The schematic of the proposed method. Locations of interest are shown with maximum inundation extent on the training set. S-net station segments are marked with colored lines. Credit: Nature Communications (2022). DOI: 10.1038/s41467-022-33253-5
Detailed predictions about how an approaching tsunami will impact the northeastern coastline in Japan can be made in fractions of a second rather than half an hour or so—buying precious time for people to take appropriate action. This potentially life-saving technology exploits the power of machine learning.
The catastrophic tsunami that struck northeast Japan on March 11, 2011 claimed the lives of about 18,500 people. Many lives might have been saved if early warning of the impending tsunami had included accurate predictions of how high the water would reach at different points along the coastline and further inland.
The coast now boasts the world’s largest network of sensors for monitoring movement of the ocean floor. The 150 offshore stations making up this network provide early warning of tsunamis. But to be meaningful, the data generated by the sensors needs to be converted into tsunami heights and extents along the coastline.
This usually requires numerically solving difficult nonlinear equations, which typically takes about 30 minutes on a standard computer. But the 2011 tsunami hit some parts of the coast a mere 45 minutes after the earthquake.
Now, Iyan Mulia of the RIKEN Prediction Science Laboratory and co-workers have used machine learning to cut the calculation time to less than one second.
“The main advantage of our method is the speed of predictions, which is crucial for early warning,” explains Mulia. “Conventional tsunami modeling provides predictions after 30 minutes, which is too late. But our model can make predictions within seconds.”
Since tsunamis are rare occurrences, the team trained their machine-learning system using more than 3,000 computer-generated tsunami events. They then tested it with 480 other tsunami scenarios and three actual tsunamis. Their machine-learning-based model could achieve comparable accuracy at only 1% the computational effort.
The same deep-learning approach could be used for other disaster scenarios where time is of the essence. “The sky’s the limit—you can apply this method to any kind of disaster predictions where the time constraint is very limited,” says Mulia, who first became interested in studying tsunamis after the 2004 Indian Ocean tsunami devastated coastal regions in his home country of Indonesia. “I’m now working on a storm surge prediction, also using machine learning.”
The work is published in the journal Nature Communications.
Mulia notes that the method is only accurate for large tsunamis that are higher than about 1.5 meters, so he and his team are now seeking to improve its accuracy for smaller tsunamis.
Reference:
Iyan E. Mulia et al, Machine learning-based tsunami inundation prediction derived from offshore observations, Nature Communications (2022). DOI: 10.1038/s41467-022-33253-5
Note: The above post is reprinted from materials provided by RIKEN.
Summer precipitation and black carbon emission characteristics. a The spatial pattern of summer precipitation using the Climatic Research Unit (CRU) dataset overlain with summer 500 hPa wind fields for the period 2001–2016, using the ERA-Interim dataset over the Tibetan plateau (TP) and South Asia (denoted by red polygon). NTP and STP delineate the northern and southern Tibetan plateau boundaries.
Black carbon aerosol is the product of incomplete combustion of fossil fuels and biomass, and has strong light absorption. Black carbon deposition in snow ice reduces the albedo of the snow ice surface, accelerating the melting of glaciers and snow cover, and thus changing the hydrological process and water resources in the region.
The South Asia region adjacent to the Tibetan Plateau is one of the regions with high black carbon emission in the world. Black carbon aerosol from South Asia can transport across the Himalayan Mountains to the inland region of the Tibetan Plateau.
Recently, a joint research team led by Prof. Kang Shichang from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS), Prof. Chen Deliang from the University of Gothenburg and Prof. Robert Gillies from the Utah State University analyzed the influence of black carbon aerosols on regional precipitation and glaciers over the Qinghai-Tibet Plateau.
Their findings were published in Nature Communications on Nov. 30.
The researchers found that since the 21st century, the South Asian black carbon aerosols have indirectly affected the material supply of the Tibetan Plateau glaciers by changing water vapor transport in the South Asian monsoon.
“Black carbon aerosols in South Asia heat up the middle and upper atmosphere, thus increasing the north-south temperature gradient,” said Prof. Kang. “Accordingly, the convective activity in South Asia is enhanced, which causes convergence of water vapor in South Asia. Meanwhile, black carbon also increases the number of cloud condensation nuclei in the atmosphere.”
These changes in meteorological conditions caused by black carbon aerosols make more water vapor form precipitation in South Asia, and less water vapor transmit to the Tibetan Plateau. As a result, precipitation in the central and southern Tibetan Plateau decreases during monsoon, especially in the southern part of the Tibetan Plateau.
The decrease of precipitation further leads to the decrease of material supply of glaciers. From 2007 to 2016, the reduced material supply accounted for 11.0% of the average glacier material loss on the Tibetan Plateau and 22.1% in the southern part of the plateau.
“The transboundary transport and deposition of black carbon aerosols in South Asia accelerate glacier ablation on the Tibetan Plateau. Meanwhile, the reduction of plateau summer precipitation will reduce the material supply of plateau glacier, which will increase the amount of glacier material deficit,” said Prof. Kang.
Reference:
Junhua Yang et al, South Asian black carbon is threatening the water sustainability of the Asian Water Tower, Nature Communications (2022). DOI: 10.1038/s41467-022-35128-1
A team from the University of South Florida is on the ground in Hawaii studying Mauna Loa, the largest active volcano in the world, to improve efforts that can help protect residents from lava flow. While slow-moving, lava averages 2,200 degrees Fahrenheit and destroys everything in its path.
The team is collecting data that will be used to create models that can help improve lava flow forecasting tools that are useful in determining how hazards impact populations. One such tool, known as MOLASSES, is a simulation engine that forecasts inundation areas of lava flow.
MOLASSES was created by USF geosciences Professor Chuck Connor, who says using the radar to gather data is essential in understanding volcano topography and improving the lava flow models.
“We want to make hazard maps that help people understand where they live and what the risks are,” Connor said. “We can’t stop a volcano from erupting, but we can give people warning about the lava flow.”
Shortly after Mauna Loa’s eruption in late November — the first since 1984 — USF geosciences Professor Tim Dixon sent two graduate students, Taha Chorsi and Mahsa Afra, to Hawaii with a Terrestrial Radar Interferometer, a rare, ground-based instrument that measures where the landscape is changing and how quickly those changes are occurring.
Chorsi and Afra delivered the radar to USF alumna Lis Gallant, a National Science Foundation postdoctoral research fellow at the United States Geological Survey Hawaiian Volcano Observatory.
Using the radar, the USF scientists were able to capture the thickening of Mauna Loa’s lava flows. The novelty of the ground-based instrument is its ability to measure the lava’s surface and create a three-dimensional map within a span of minutes.
“A lot of volcano science happens in hostile terrains,” Gallant said. “This radar is a particularly powerful instrument because it can see through moisture, and now, we can definitely say it would be well-suited in areas where visibility is poor and to immediately help hazard response.”
The team will review this data over the next several months to determine where the Mauna Loa lava flow was moving and the velocities of those movements. The data can be used to better understand how lava flows move and advance, which in turn can be used by scientists to improve tools used to forecast lava flow hazards through models.
Dixon has had great success using the radar to monitor Earth movements in glaciers, landslides, earthquakes and volcanoes. Many of his students, including Chorsi and Afra, have worked alongside him over the years to learn the radar and develop a user manual.
“There’s probably only a hundred people in the world who can successfully use this instrument,” Dixon said.
Fig. 1: Some adult individuals watch over the newly-hatched Europasaurus chicks which are leaving the nest to join their herd. Commissioned artwork by Davide Bonadonna.
Europasaurus is a long-necked, herbivorous dinosaur that lived in the Late Jurassic, about 154 million years ago, on a small island in modern-day Germany. Recently, scientists from the universities of Vienna and Greifswald examined fossil braincase material of Europasaurus with the aid of micro-computed tomography (micro-CT). The digital reconstruction of the inner ear of Europasaurus gave the researchers new insights not only into its hearing ability, but also into its reproductive and social behaviour. The study was recently published in eLife.
Like its famous relative Brachiosaurus, Europasaurus belongs to the group of sauropod dinosaurs, which include the largest land-living animals that ever lived on Earth. Some representatives could attain body lengths of around 40 metres, possibly weighing up to 80 metric tons. However, Europasaurus holgeri was a comparatively small sauropod species with a body height of up to three metres.
Europasaurus, which lived about 154 million years ago on an island in modern-day Germany, constitutes the first dinosaur for which the evolutionary phenomenon of insular dwarfism was demonstrated: large island-dwelling animals become smaller over a number of generations. Possibly, Europasaurus represents the fossil counterpart to the recent Sumatran tiger and rhino, which are smaller than their closest relatives from the mainland.
Fossil skull remains of very young to fully-grown adults have been examined
For the study that has just been published, scientists from the universities of Greifswald and Vienna examined fossil braincase material of Europasaurus, belonging to different age stages: from very young and small individuals to adult ones. In order to learn more about these long extinct animals, the researchers reconstructed the cavities that once housed the brain and inner ears with the aid of micro-CT.
The part of the inner ear being responsible for hearing, the lagena or cochlea, turns out to be relatively long in Europasaurus. This suggests that these animals had a good sense of hearing, rendering intraspecific communication crucial and gregarious behavior likely.
Europasaurus was probably precocial
Another part of the inner ear is relevant for the sense of equilibrium and consists of three tiny arches. The scientists found that the inner ear cavities within very small specimens resemble the respective cavities of adults in form and size. “This supposes that very young individuals of Europasaurus strongly relied on the ability to equilibrate already. Some considered skull remains were so tiny (~2 cm) that they may belong to hatchlings, which renders the species precocial,” says Sebastian Stumpf from the University of Vienna. Whereas some sauropods weighed several tens of tons more than their newly-hatched offspring (posing a lethal threat for the latter), the hatchlings of Europasaurus may have immediately followed the herd in some approximation.
Reference:
Marco Schade, Nils Knötschke, Marie K Hörnig, Carina Paetzel, Sebastian Stumpf. Neurovascular anatomy of dwarf dinosaur implies precociality in sauropods. eLife, 2022; 11 DOI: 10.7554/eLife.82190
Close up photograph of the mammal foot among the ribs of Microraptor. Photograph by Hans Larsson, who retains the copyright on these images. These may be used in any article in association with this story. / Gros plan photo du pied de mammifère parmi les côtes de Microraptor. Photographie de Hans Larsson, qui détient les droits d’auteur sur ces images. Ceux-ci peuvent être utilisés dans n’importe quel article en association avec cette histoire.
Microraptor was an opportunistic predator, feeding on fish, birds, lizards — and now small mammals. The discovery of a rare fossil reveals the creature was a generalist carnivore in the ancient ecosystem of dinosaurs.
Finding the last meal of any fossil animal is rare. When McGill University Professor Hans Larsson saw a complete mammal foot inside the rib cage of the small, feathered dinosaur, his jaw dropped. Of the many hundreds of carnivorous dinosaur skeletons, only 20 cases preserve their last meals. This new find makes 21.
“At first, I couldn’t believe it. There was a tiny rodent-like mammal foot about a centimeter long perfectly preserved inside a Microraptor skeleton. These finds are the only solid evidence we have about the food consumption of these long extinct animals — and they are exceptionally rare,” says Larsson, who came across the fossil while visiting museum collections in China.
Microraptor was not a picky eater
Fully feathered with wings on both its arms and legs, this dinosaur is closely linked to the origin of birds. Microraptor was about the size of a crow and one of the smallest dinosaurs. The first specimen was discovered in deposits in Liaoning, China, in the early 2000s.
“We already know of Microraptor specimens preserved with parts of fish, a bird, and a lizard in their bellies. This new find adds a small mammal to their diet, suggesting these dinosaurs were opportunistic and not picky eaters,” says Larsson who is a Professor of Biology at the Redpath Museum of McGill University.
“Knowing they were not specialized to any particular food is a big deal,” he adds. According to the team of researchers, this could be the first evidence of a generalist carnivore in dinosaur ecosystems. Generalist predators are important stabilizers in today’s ecosystems, like foxes and crows, because they can feed among several species that may have differing population abundances.
“Knowing that Microraptor was a generalist carnivore puts a new perspective on how ancient ecosystems may have worked and a possible insight into the success of these small, feathered dinosaurs,” says Larsson.
Reference:
David W. E. Hone, T. Alexander Dececchi, Corwin Sullivan, Xu Xing, Hans C. E. Larsson. Generalist diet of Microraptor zhaoianus included mammals. Journal of Vertebrate Paleontology, 2022; DOI: 10.1080/02724634.2022.2144337
Artist’s life reconstruction of adult and newly born Triassic ichthyosaurs Shonisaurus, 2022. Credit: Gabriel Ugueto.
Today’s marine giants — such as blue and humpback whales — routinely make massive migrations across the ocean to breed and give birth in waters where predators are scarce, with many congregating year after year along the same stretches of coastline. Now, new research from a team of scientists — including researchers with the Smithsonian Institution, Vanderbilt University, the Natural History Museum of Utah, the University of Utah, University of Nevada, Reno, University of Edinburgh, University of Texas at Austin, Vrije Universiteit Brussels and University of Oxford — suggests that nearly 200 million years before giant whales evolved, school bus-sized marine reptiles called ichthyosaurs may have been making similar migrations to breed and give birth together in relative safety.
The findings, published today in the journal Current Biology, examine a rich fossil bed in the renowned Berlin-Ichthyosaur State Park (BISP) in Nevada’s Humboldt-Toiyabe National Forest, where many 50-foot-long ichthyosaurs (Shonisaurus popularis)lay petrified in stone. Led by Neil Kelley, Vanderbilt University scientist and former Smithsonian’s National Museum of Natural History Peter Buck postdoctoral fellow, and co-authored by the museum’s curator of fossil marine mammals Nicholas Pyenson, the study offers a plausible explanation as to how at least 37 of these marine reptiles came to meet their ends in the same locality — a question that has vexed paleontologists for more than half a century.
“We present evidence that these ichthyosaurs died here in large numbers because they were migrating to this area to give birth for many generations across hundreds of thousands of years,” Pyenson said. “That means this type of behavior we observe today in whales has been around for more than 200 million years.”
Over the years, some paleontologists have proposed that BISP’s ichthyosaurs — predators resembling oversized chunky dolphins that have been adopted as Nevada’s state fossil — died in a mass stranding event such as those that sometimes afflicts modern whales, or that the creatures were poisoned by toxins from a nearby harmful algal bloom. The problem is that these hypotheses lack strong lines of scientific evidence to support them.
To try to solve this prehistoric mystery, the team combined newer paleontological techniques such as 3D scanning and geochemistry with traditional paleontological perseverance by poring over archival materials, photographs, maps, field notes and drawer after drawer of museum collections for shreds of evidence that could be reanalyzed.
Although most well-studied paleontological sites excavate fossils so they can be more closely studied by scientists at research institutions, the main attraction for visitors to the Nevada State Park-run BISP is a barn-like building that houses what researchers call Quarry 2, an array of ichthyosaurs that have been left embedded in the rock for the public to see and appreciate. Quarry 2 has partial skeletons from an estimated seven individual ichthyosaurs that all appear to have died around the same time.
“When I first visited the site in 2014, my first thought was that the best way to study it would be to create a full-color, high-resolution 3D model,” Kelley said. “A 3D model would allow us to study the way these large fossils were arranged in relation to one another without losing the ability to go bone by bone.”
To do this, Kelley, Pyenson and the research team collaborated with Jon Blundell, a member of the Smithsonian Digitization Program Office’s 3D Program team, and Holly Little, a long-time collaborator with Pyenson and the 3D Program’s team and currently the informatics manager in the museum’s Department of Paleobiology. While Pyenson and Kelley were physically measuring bones and studying the site using traditional paleontological techniques, Little and Blundell used digital cameras and a spherical laser scanner to take hundreds of photographs and millions of point measurements that were then stitched together using specialized software to create a 3D model of the fossil bed.
To further home in on what might have befallen these extinct marine reptiles, the team collected tiny samples of the rock surrounding the fossils and performed a series of geochemical tests to look for signs of environmental disturbance.
One test measured mercury, which often accompanies large-scale volcanic activity, and found no significantly increased levels. Other tests examined different types of carbon and determined that there was no evidence of sudden increases in organic matter in the marine sediments that would result in a dearth of oxygen in the surrounding waters (though, like whales, the ichthyosaurs breathed air).
These geochemical tests revealed no signs that these ichthyosaurs perished because of some cataclysm that would have seriously disturbed the ecosystem in which they died. Kelley, Pyenson and other colleagues on the research team continued to look beyond Quarry 2 to the surrounding geology and all the fossils that had previously been excavated from the area.
The geologic evidence indicates that when the ichthyosaurs died, their bones eventually sank to the bottom of the sea, rather than along a shoreline shallow enough to suggest stranding, ruling out another hypothesis. Even more telling, though the area’s limestone was chockfull of large adult Shonisaurus specimens, other marine vertebrates were scarce. The bulk of the other fossils at BISP come from small invertebrates such as clams and ammonites (spiral-shelled relatives of today’s squid).
“There are so many large, adult skeletons from this one species at this site and almost nothing else,” Pyenson said. “There are virtually no remains of things like fish or other marine reptiles for these ichthyosaursto feed on, and there are also no juvenile Shonisaurus skeletons.”
The researchers’ paleontological dragnet had eliminated some of the potential causes of death and started to provide intriguing clues about the type of ecosystem these marine predators were swimming in, but the evidence still did not clearly point to an alternative explanation.
The research team found a key piece of the puzzle when they discovered tiny ichthyosaur remains among new fossils collected at BISP and hiding within older museum collections. Careful comparison of the bones and teeth using micro-CT X-ray scans at Vanderbilt University revealed that these small bones were in fact embryonic and newborn Shonisaurus.
“Once it became clear that there was nothing for them to eat here, and there were large adult Shonisaurus along with embryos and newborns but no juveniles, we started to seriously consider whether this might have been a birthing ground,” Kelley said.
Further analysis of the various strata in which the different clusters of ichthyosaur bones were found also revealed that the ages of the many fossil beds of BISP were separated by at least hundreds of thousands of years, if not millions.
“Finding these different spots with the same species spread across geologic time with the same demographic pattern tells us that this was a preferred habitat that these large oceangoing predators returned to for generations,” Pyenson said. “This is a clear ecological signal, we argue, that this was a place that Shonisaurus used to give birth, very similar to today’s whales. Now we have evidence that this sort of behavior is 230 million years old.”
Kelley said the next step for this line of research is to investigate other ichthyosaur and Shonisaurus sites in North America with these new findings in mind to begin to recreate their ancient world — perhaps by looking for other breeding sites or for places with greater diversity of other species that could have been rich feeding grounds for this extinct apex predator.
The 3D scans of the site are now available for other researchers to study and for the public to explore via the open-source Smithsonian’s Voyager platform, which is developed and maintained by Blundell’s team members at the Digitization Program Office. An interactive digital experience about the research team’s study, including a 3D model of ichthyosaur sites analyzed, is also available on the Digitization Program Office’s website.
“Our work is public,” Blundell said. “We aren’t just scanning sites and objects and locking them up. We create these scans to open up the collection to other researchers and members of the public who can’t physically get to the Smithsonian.”
This research was conducted under research permits issued by the U.S. Forest Service and Nevada State Parks, and it was supported by funding from the Smithsonian, University of Nevada, Reno, Vanderbilt University and University of Utah.
Reference:
Neil P. Kelley, Randall B. Irmis, Paige E. dePolo, Paula J. Noble, Danielle Montague-Judd, Holly Little, Jon Blundell, Cornelia Rasmussen, Lawrence M.E. Percival, Tamsin A. Mather, Nicholas D. Pyenson. Grouping behavior in a Triassic marine apex predator. Current Biology, 2022; 32 (24): 5398 DOI: 10.1016/j.cub.2022.11.005
Dinosaur ancestors are shown in this artist’s conception of life in the Chañares formation approximately 235 million years. Credit: Victor O. Leshyk / www.paleovista.com
Climate change, rather than competition, played a key role in the ascendancy of dinosaurs through the Late Triassic and Early Jurassic periods.
According to new research, changes in global climate associated with the Triassic-Jurassic mass extinction — which wiped out many large terrestrial vertebrates such as the giant armadillo-like aetosaurs — actually benefitted the earliest dinosaurs.
In particular, sauropod-like dinosaurs, which became the giant herbivore species of the later Jurassic like Diplodocus and Brachiosaurus, were able to thrive and expand across new territories as the planet warmed up after the extinction event, 201 million years ago.
The new evidence is published in Current Biology, by an international team of palaeontologists led by the Universities of Birmingham and Bristol, in the UK, Friedrich-Alexander University Erlangen-Nu?rnberg (FAU), in Germany, and the University of São Paulo in Brazil.
The team compared computer models of prehistoric global climate conditions such as temperature and rainfall with data on the different locations of dinosaurs taken from sources such as the Paleobiology Database. They showed how the sauropods, and sauropod-like animals, with their long tails and necks and small heads, were the runaway success story of a turbulent period of evolution.
Dr Emma Dunne, now a lecturer in palaeontology at FAU, carried out the research while at the University of Birmingham. She said: “What we see in the data suggests that instead of dinosaurs being outcompeted by other large vertebrates, it was variations in climate conditions that were restricting their diversity. But once these conditions changed across the Triassic-Jurassic boundary, they were able to flourish.
“The results were somewhat surprising, because it turns out that sauropods were really fussy from the get-go: later in their evolution they continue to stay in warmer areas and avoid polar regions.”
Co-author on the paper, Professor Richard Butler, at the University of Birmingham, said: “Climate change appears to have been really important in driving the evolution of early dinosaurs. What we want to do next is use the same techniques to understand the role of climate in the next 120 million years of the dinosaur story.”
The research was funded by the Leverhulme Trust and the European Research Council.
Reference:
Emma M. Dunne, Alexander Farnsworth, Roger B.J. Benson, Pedro L. Godoy, Sarah E. Greene, Paul J. Valdes, Daniel J. Lunt, Richard J. Butler. Climatic controls on the ecological ascendancy of dinosaurs. Current Biology, 2022; DOI: 10.1016/j.cub.2022.11.064
Pterodactylus antiquus, DMA-JP-2014/004, from the Upper Jurassic (Kimmeridgian) Torleite Formation of Painten; overview photograph.
Pterosaurs, the flying reptiles of the dinosaur era, originated in the Late Triassic (227 million years ago) and became extinct at the end-Cretaceous extinction event (66 million years ago). With wing spans ranging from 1 to 12 meters, they dominated the world’s skies for more than 160 million years.
The first described and named pterosaur — and namesake of the whole group — is Pterodactylus from the famous Solnhofen Limestone of Bavaria, southern Germany. Originally described in 1784 by the Italian naturalist Cosimo Alessandro Collini, the fossil was considered to be an aquatic animal for 25 years, before Georges Cuvier found out it was a flying reptile belonging to a new, previously unrecognized group.
The oldest specimen of this iconic pterosaur was recently found near Painten, a small town in the southern part of the Franconian Alb in central Bavaria. The fossil, described in a study in the journal Fossil Record, is about one million years older than other Pterodactylus specimens.
The specimen was unearthed in 2014 during excavations in an active limestone quarry. It took more than 120 hours of meticulous mechanical work using pneumatic tools and needles before the researchers could study it. The research team behind the discovery are Felix Augustin, Andreas Matzke, Panagiotis Kampouridis and Josephina Hartung from the University of Tübingen (Germany) and Raimund Albersdörfer from the Dinosaurier Museum Altmühltal (Germany).
“The rocks of the quarry, which yielded the new Pterodactylus specimen, consist of silicified limestone that has been dated to the upper Kimmeridgian stage (around 152 million years ago),” explains Felix Augustin of the University of Tübingen, who is the lead author of the study. “Previously, Pterodactylus had only been found in younger rocks of southern Germany belonging to the Tithonian stage that follows after the Kimmeridgian.”
The specimen is a complete, well-preserved skeleton of a small-sized individual. “Only a very small portion of the left mandible as well as of the left and right tibia is missing. Otherwise, the skeleton is nearly perfectly preserved with every bone present and in its roughly correct anatomical position,” the researchers write in their study.
With a 5-cm-long skull, the Painten Pterodactylus represents a rare “sub-adult” individual. “Generally, the Pterodactylus specimens are not evenly distributed across the full size range but predominantly fall into distinct size-classes that are separated by marked gaps. The specimen from Painten is a rare representative of the first gap between the small and large sizes,” explains Augustin. “The Painten Pterodactylus was of an intermediate, and rarely found, ontogenetic age at the time of its death, between two consecutive year-classes.”
The Painten quarry has yielded many other “exquisitely preserved fossils,” including ichthyosaurs, turtles, marine and terrestrial crocodile-relatives, and dinosaurs. Many of them, like this new pterosaur specimen, are on display in the new Dinosaurier Museum Altmühltal in Denkendorf (Bavaria, Germany).
Reference:
Felix J. Augustin, Panagiotis Kampouridis, Josephina Hartung, Raimund Albersdörfer, Andreas T. Matzke. The geologically oldest specimen of Pterodactylus: a new exquisitely preserved skeleton from the Upper Jurassic (Kimmeridgian) Plattenkalk deposits of Painten (Bavaria, Germany). Fossil Record, 2022; 25 (2): 331 DOI: 10.3897/fr.25.90692
Fossils from the Fezouata Shale. From left to right, a non-mineralized arthropod (Marrellomorpha), a palaeoscolecid worm and a trilobites. Credit Emmanuel Martin.
Discoveries at a major new fossil site in Morocco suggest giant arthropods — relatives of modern creatures including shrimps, insects and spiders — dominated the seas 470 million years ago.
Early evidence from the site at Taichoute, once undersea but now a desert, records numerous large “free-swimming” arthropods.
More research is needed to analyse these fragments, but based on previously described specimens, the giant arthropods could be up to 2m long.
An international research team say the site and its fossil record are very different from other previously described and studied Fezouata Shale sites from 80km away.
They say Taichoute (considered part of the wider “Fezouata Biota”) opens new avenues for paleontological and ecological research.
“Everything is new about this locality — its sedimentology, paleontology, and even the preservation of fossils — further highlighting the importance of the Fezouata Biota in completing our understanding of past life on Earth,” said lead author Dr Farid Saleh, from the University of Lausanne and and Yunnan University.
Dr Xiaoya Ma, from the University of Exeter and Yunnan University, added: “While the giant arthropods we discovered have not yet been fully identified, some may belong to previously described species of the Fezouata Biota, and some will certainly be new species.
“Nevertheless, their large size and free-swimming lifestyle suggest they played a unique role in these ecosystems.”
The Fezouata Shale was recently selected as one of the 100 most important geological sites worldwide because of its importance for understanding the evolution during the Early Ordovician period, about 470 million years ago.
Fossils discovered in these rocks include mineralised elements (eg shells), but some also show exceptional preservation of soft parts such as internal organs, allowing scientists to investigate the anatomy of early animal life on Earth.
Animals of the Fezouata Shale, in Morocco’s Zagora region, lived in a shallow sea that experienced repeated storm and wave activities, which buried the animal communities and preserved them in place as exceptional fossils.
However, nektonic (or free-swimming) animals remain a relatively minor component overall in the Fezouata Biota.
The new study reports the discovery of the Taichoute fossils, preserved in sediments that are a few million years younger than those from the Zagora area and are dominated by fragments of giant arthropods.
“Carcasses were transported to a relatively deep marine environment by underwater landslides, which contrasts with previous discoveries of carcass preservation in shallower settings, which were buried in place by storm deposits,” said Dr Romain Vaucher, from the University of Lausanne.
Professor Allison Daley, also from the University of Lausanne, added: “Animals such as brachiopods are found attached to some arthropod fragments, indicating that these large carapaces acted as nutrient stores for the seafloor dwelling community once they were dead and lying on the seafloor.”
Dr Lukáš Laibl, from the Czech Academy of Sciences, who had the opportunity to participate in the initial fieldwork, said: “Taichoute is not only important due to the dominance of large nektonic arthropods.
“Even when it comes to trilobites, new species so far unknown from the Fezouata Biota are found in Taichoute.”
Dr Bertrand Lefebvre, from the University of Lyon, who is the senior author on the paper, and who has been working on the Fezouata Biota for the past two decades, concluded: “The Fezouata Biota keeps surprising us with new unexpected discoveries.”
The paper, published in the journal Scientific Reports, is entitled: “New fossil assemblages from the Early Ordovician Fezouata Biota.”
Reference:
Farid Saleh, Romain Vaucher, Muriel Vidal, Khadija El Hariri, Lukáš Laibl, Allison C. Daley, Juan Carlos Gutiérrez-Marco, Yves Candela, David A. T. Harper, Javier Ortega-Hernández, Xiaoya Ma, Ariba Rida, Daniel Vizcaïno, Bertrand Lefebvre. New fossil assemblages from the Early Ordovician Fezouata Biota. Scientific Reports, 2022; 12 (1) DOI: 10.1038/s41598-022-25000-z
A seismogram of 2011 Tōhoku earthquake and tsunami recorded at Weston Observatory in Massachusetts, USA. Credit: Image from Wikimedia Commons.
The great 2011 earthquake that caused the tsunami in northeastern Japan is still remembered for its destructive power.
Also known as the Mw 9.0 Tohoku earthquake, the seismic nature of this calamity was not initially entirely clear. While earthquakes resulting from built-up tectonic stress in reverse faulting had only been partially released. In previous studies where complete releases have been posited, the hypothesis was based on seismicity observation and simulation, or on direct stress measurement data above the fault only by using log data.
Now, a team of researchers at Kyoto University has found evidence that a complete stress release may have contributed to the record-breaking event.
“The minor differences between maximum and minimum post-earthquake horizontal stresses near the fault suggest that the Tohoku earthquake occurred upon a complete stress release,” explains lead author Weiren Lin.
The team found that both sedimentary formations above and below the plate boundary fault lie in the stress state of normal faults in which vertical stress is greater than maximum horizontal stress.
“Knowledge about stress changes before and after this earthquake, both above and below a gently dipping fault, can provide us insights into how fault slipping caused the ensuing tsunami,” the author reflects.
Lin’s team was able to collect data for the stress state above the source fault of the Tohoku earthquake, at the boundary between the North American plate and the subducting Pacific plate. However, geophysical data for the stress state below this zone was unreliable.
To address this problem, the team studied one of four drill core samples collected by the Japan Trench Fast — or JFAST — Drilling Project from below the source fault and was the first to successfully reveal the stress state at that depth.
“Our new data show good consistency with previous results above the fault, suggesting that combining geophysical data and core samples to comprehensively investigate stress states is effective.”
Reference:
Weiren Lin, Yuhji Yamamoto, Takehiro Hirose. Three-dimensional stress state above and below the plate boundary fault after the 2011 Mw 9.0 Tohoku earthquake. Earth and Planetary Science Letters, 2023; 601: 117888 DOI: 10.1016/j.epsl.2022.117888
Artist’s impression of an individual 525-million-year-old Cardiodictyon catenulum on the shallow coastal sea floor, emerging from the shelter of a small stromatolite, rock-like structures built by microorganisms that were common at the time. Credit: Nicholas Strausfeld
Fossils of a tiny sea creature that died more than half a billion years ago may compel a science textbook rewrite of how brains evolved.
A study published in Science — led by Nicholas Strausfeld,a Regents Professor in the University of Arizona Department of Neuroscience, and Frank Hirth, a reader of evolutionary neuroscience at King’s College London — provides the first detailed description of Cardiodictyon catenulum, a wormlike animal preserved in rocks in China’s southern Yunnan province. Measuring barely half an inch (less than 1.5 centimeters) long and initially discovered in 1984, the fossil had hidden a crucial secret until now: a delicately preserved nervous system, including a brain.
“To our knowledge, this is the oldest fossilized brain we know of, so far,” Strausfeld said.
Cardiodictyon belonged to an extinct group of animals known as armored lobopodians, which were abundant early during a period known as the Cambrian, when virtually all major animal lineages appeared over an extremely short time between 540 million and 500 million years ago. Lobopodians likely moved about on the sea floor using multiple pairs of soft, stubby legs that lacked the joints of their descendants, the euarthropods — Greek for “real jointed foot.” Today’s closest living relatives of lobopodians are velvet worms that live mainly in Australia, New Zealand and South America.
Fossils of Cardiodictyon reveal an animal with a segmented trunk in which there are repeating arrangements of neural structures known as ganglia. This contrasts starkly with its head and brain, both of which lack any evidence of segmentation.
“This anatomy was completely unexpected because the heads and brains of modern arthropods, and some of their fossilized ancestors, have for over a hundred years been considered as segmented,” Strausfeld said.
According to the authors, the finding resolves a long and heated debate about the origin and composition of the head in arthropods, the world’s most species-rich group in the animal kingdom. Arthropods include insects, crustaceans, spiders and other arachnids, plus some other lineages such as millipedes and centipedes.
“From the 1880s, biologists noted the clearly segmented appearance of the trunk typical for arthropods, and basically extrapolated that to the head,” Hirth said. “That is how the field arrived at supposing the head is an anterior extension of a segmented trunk.”
“But Cardiodictyon shows that the early head wasn’t segmented, nor was its brain, which suggests the brain and the trunk nervous system likely evolved separately,” Strausfeld said.
Brains do fossilize
Cardiodictyon was part of the Chengjiang fauna, a famous deposit of fossils in the Yunnan Province discovered by paleontologist Xianguang Hou. The soft, delicate bodies of lobopodians have preserved well in the fossil record, but other than Cardiodictyon none have been scrutinized for their head and brain, possibly because lobopodians are generally small. The most prominent parts of Cardiodictyon were a series of triangular, saddle-shaped structures that defined each segment and served as attachment points for pairs of legs. Those had been found in even older rocks dating back to the advent of the Cambrian.
“That tells us that armored lobopodians might have been the earliest arthropods,” Strausfeld said, predating even trilobites, an iconic and diverse group of marine arthropods that went extinct around 250 million years ago.
“Until very recently, the common understanding was ‘brains don’t fossilize,'” Hirth said. “So you would not expect to find a fossil with a preserved brain in the first place. And, second, this animal is so small you would not even dare to look at it in hopes of finding a brain.”
However, work over the last 10 years, much of it done by Strausfeld, has identified several cases of preserved brains in a variety of fossilized arthropods.
A common genetic ground plan for making a brain
In their new study, the authors not only identified the brain of Cardiodictyon but also compared it with those of known fossils and of living arthropods, including spiders and centipedes. Combining detailed anatomical studies of the lobopodian fossils with analyses of gene expression patterns in their living descendants, they conclude that a shared blueprint of brain organization has been maintained from the Cambrian until today.
“By comparing known gene expression patterns in living species,” Hirth said, “we identified a common signature of all brains and how they are formed.”
In Cardiodictyon, three brain domains are each associated with a characteristic pair of head appendages and with one of the three parts of the anterior digestive system.
“We realized that each brain domain and its corresponding features are specified by the same combination genes, irrespective of the species we looked at,” added Hirth. “This suggested a common genetic ground plan for making a brain.”
Lessons for vertebrate brain evolution
Hirth and Strausfeld say the principles described in their study probably apply to other creatures outside of arthropods and their immediate relatives. This has important implications when comparing the nervous system of arthropods with those of vertebrates, which show a similar distinct architecture in which the forebrain and midbrain are genetically and developmentally distinct from the spinal cord, they said.
Strausfeld said their findings also offer a message of continuity at a time when the planet is changing dramatically under the influence of climatic shifts.
“At a time when major geological and climatic events were reshaping the planet, simple marine animals such as Cardiodictyon gave rise to the world’s most diverse group of organisms — the euarthropods — that eventually spread to every emergent habitat on Earth, but which are now being threatened by our own ephemeral species.”
Funding for this work was provided by the National Science Foundation, the University of Arizona Regents Fund, and the UK Biotechnology and Biological Sciences Research Council.
Reference:
Nicholas J. Strausfeld, Xianguang Hou, Marcel E. Sayre, Frank Hirth. The lower Cambrian lobopodian Cardiodictyon resolves the origin of euarthropod brains. Science, 2022; 378 (6622): 905 DOI: 10.1126/science.abn6264
Artistic reconstruction of the Ordovician fossils Mieridduryn bonniae. Original artwork by Franz Anthony
The most famous fossils from the Cambrian explosion of animal life over half a billion years ago are very unlike their modern counterparts. These “weird wonders,” such as the five-eyed Opabinia with its distinctive frontal proboscis, and the fearsome apex predator Anomalocaris with its radial mouthparts and spiny feeding appendages, have become icons in popular culture. However, they were only quite recently recognised as extinct stages of evolution that are crucial for understanding the origins of one of the largest and most important animal phyla, the arthropods (a group that includes modern crabs, spiders, and millipedes).
In an article published today in Nature Communications, two new specimens with striking similarities to Opabinia are described from a new fossil deposit recording life in the Ordovician Period, 40 million years after the Cambrian explosion. This deposit, located in a sheep field near Llandrindod Wells in mid Wales (UK), was discovered during the COVID-19 lockdowns by independent researchers and Llandrindod residents Dr Joseph Botting and Dr Lucy Muir, Honorary Research Fellows at Amgueddfa Cymru — National Museum Wales.
The quarry is well known as one of several local sites yielding new species of fossil sponges. “When the lockdown started, I thought I’d make one more trip to collect some last sponges before finally writing them up,” said Botting, “of course, that was the day that I found something sticking its tentacles out of a tube instead.”
“This is the sort of thing that palaeontologists dream of, truly soft-body preservation,” said Muir, “we didn’t sleep well, that night.” That was the beginning of an extensive and ongoing investigation that grew into an international collaboration, with lead author Dr Stephen Pates (University of Cambridge) and senior author Dr Joanna Wolfe (The Department of Organismic and Evolutionary Biology at Harvard University).
Among the fossils unearthed so far are two very unexpected leftovers from the Cambrian “weird wonders.” Pates met with Botting and Muir to study the specimens using microscopes purchased through crowd-funding to examine the tiny specimens. The larger specimen measured 13 mm, while the smaller measured a miniscule 3 mm (for comparison Opabinia specimens can be 20 times as long).
Exhaustive studies during this visit revealed additional details in the new specimens. Some of these features are also found in Opabinia, such as triangular, squishy lobopod ‘legs’ for interacting with the sediment, and — in the smaller specimen — a tail fan with blades similar in shape to Opabinia’s recently described sister, Utaurora. However other features recognised in the material, such as sclerites covering the head as well as the presence of spines on the proboscis, were not known from any opabiniid and instead hinted at possible radiodont (including Anomalocaris) affinities. The differences between the two specimens led the researchers to wonder were these due to changes during the growth of one species, or did they instead suggest that two distinct species were present in this new deposit?
The authors describe the new taxon, Mieridduryn bonniae, with the larger specimen designated the holotype. The status of the smaller specimen was left open, reflecting these different possibilities. “The size of the smaller specimen is comparable to some modern arthropod larvae — we had to take into account this possibility in our analyses,” said Wolfe.
The genus name Mieridduryn is derived from the Welsh language, and translates as “bramble-snout,” reflecting the spiny proboscis in the new material. It is pronounced like “me-airy-theerin.” “Many scientific names are made using Latin or Greek words,” Muir said, “but we really wanted to honour Wales, where the specimens were discovered, and so chose to use the Welsh language.” The species name bonniae pays tribute to the niece of the landowners, Bonnie. “The landowners have been very supportive of our research, and Bonnie has been avidly following our progress, even attending some of our Zoom updates,” said Botting.
The researchers used phylogenetic analyses, comparing the new fossils with 57 other living and fossil arthropods, radiodonts, and panarthropods, to determine their place in the history of arthropod evolution. “The best-supported position for our Welsh specimens, whether considered as one or two species, were more closely related to modern arthropods than to opabiniids. These analyses suggested that Mieridduryn and the smaller specimen were not “true” opabiniids,” said Pates.
Crucially, these results suggested that a proboscis — thought to represent a fused pair of head appendages — was not unique to opabiniids, but instead was present in the common ancestor of radiodonts and deuteropods (more derived, modern arthropods), and through evolutionary time may have reduced to become the labrum that covers the mouth in modern arthropods. However, the second-best-supported position for these specimens was as true opabiniids, so the authors enquired a bit further to test the robustness of this first result.
“These Welsh animals are 40 million years younger than Opabinia and Utaurora” said Wolfe, “so it was important to assess the implications of some features, such as spines on the appendages or a carapace, evolving convergently with radiodonts in our analyses.” If some, or all, the features shared between the Welsh animals and radiodonts were instead considered to have evolved convergently, the analyses strongly favoured these specimens being considered true opabiniids, the first from outside North America and the youngest by 40 million years. Whatever the eventual conclusion, the fossils are an important new piece in the arthropod evolutionary jigsaw.
These small but scientifically mighty fossils are some of the first findings from this important new Ordovician fauna. Botting and Muir continue their work in the small quarry in the sheep field with more still to come. Muir added, “Even the sheep know we are on to something special here, they usually come to watch.”
Reference:
Stephen Pates, Joseph P. Botting, Lucy A. Muir, Joanna M. Wolfe. Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution. Nature Communications, 2022; 13 (1) DOI: 10.1038/s41467-022-34204-w
Thanks to its geothermally active location, the town of Kusatsu, Gunma Prefecture (in the background of this image), is one of Japan’s most popular onsen (hot springs) destinations. The acidic and vibrant turquoise Yugama crater lake, however, is definitely not suitable for swimming. Credit: Tomoya Obase
Volcanic eruptions are dangerous and difficult to predict. A team at the University of Tokyo has found that the ratio of atoms in specific gases released from volcanic fumaroles (gaps in the Earth’s surface) can provide an indicator of what is happening to the magma deep below — similar to taking a blood test to check your health. This can indicate when things might be “heating up.” Specifically, changes in the ratio of argon-40 and helium-3 can indicate how frothy the magma is, which signals the risk of different types of eruption. Understanding which ratios of which gases indicate a certain type of magma activity is a big step. Next, the team hopes to develop portable equipment which can provide on-site, real-time measurements for a 24/7 volcanic activity monitoring and early warning system.
Does the thought of standing on a volcano make you quiver with excitement, or fear? For many people, living in the shadow of a volcano is part of daily life. Japan has 111 active volcanoes and an average of 15 volcanic “events,” including eruptions, every year. But these events are notoriously difficult to predict and can be deadly. In 2014, Mount Ontake, Japan’s second-highest volcano and a famous tourist spot, unexpectedly erupted, sadly killing 58 people and leaving five missing. Earthquake activity is typically an early warning sign, but some eruptions (including the one at Ontake) can occur without clear earthquake signals and so disaster mitigators, like the Japan Meteorological Agency, would benefit from other reliable ways to forewarn residents of the next potential disaster.
Fumaroles are holes and cracks in the Earth’s surface (the crust), which release gas and steam and often occur around volcanoes. The ejected gas is made up of a mix of chemicals. Its composition can provide us with insight into what is happening below the Earth’s crust in the mantle, where magma (molten rock) forms and pushes upwards, eventually erupting as lava. Researchers already know that the ratio of isotopes (atoms from an element with the same chemical properties but different mass) of certain gases can indicate hidden magma activity. “We knew that the helium isotope ratio occasionally changes from a low value, similar to the helium found in the Earth’s crust, to a high value, like that in the Earth’s mantle, when the activity of magma increases. This was based on an observation of the helium isotope ratio of cold spring gas in El Hierro Island, in the Canary Islands (in the Atlantic Ocean off the northwestern coast of Africa), where an eruption occurred in 2011,” explained Professor Hirochika Sumino from the Research Center for Advanced Science and Technology. “But we didn’t know why we had more mantle-derived helium during magmatic unrest.”
To gain further insight, Sumino and team decided to monitor gases from six fumaroles around the active Kusatsu-Shirane volcano, which lies about 150 kilometers northwest of Tokyo in Gunma Prefecture. The team collected samples every few months for seven years between 2014 and 2021. After collection, they took the samples back to the lab and analyzed them using state-of-the-art equipment called a noble gas mass spectrometer. This enabled them to precisely measure isotopic compositions, including that of ultratrace (tiny but important) isotopes, such as helium-3, which is typically more abundant in the mantle compared to the crust or air.
“We succeeded in detecting changes in the magma-derived argon-40/helium-3 ratio, related to magmatic unrest. Using computer models, we revealed that the ratio reflects how much the magma underground is foaming, making bubbles of volcanic gases which separate from the liquid magma,” explained Sumino. “How much magma foams controls how much magmatic gas is provided to the hydrothermal system beneath a volcano and how buoyant the magma is. The former is related to a risk of phreatic eruption, in which an increase in water pressure in the hydrothermal system causes the eruption. The latter would increase the rate of magma ascent, resulting in a magmatic eruption.
“When you compare a volcano with a human body, the conventional geophysical methods represented by observations of earthquakes and crustal deformation are similar to listening to the chest and taking body size measurements. In these cases, it is difficult to know what health problem causes some noise in your chest or a sudden increase in your weight, without a detailed medical check. On the other hand, analyzing the chemical and isotope composition of elements in fumarolic gases is like a breath or blood test. This means we are looking at actual material directly derived from magma to know precisely what is going on with the magma.”
For now, gas samples have to be collected out in the field and brought back to the lab for analysis, which is a challenging and time-consuming process. However, Sumino has experience of improving noble gas mass spectrometers and hopes to develop a new tool which would enable them to perform the same analysis, but in real time and out in the field. “We want to be able to detect changes in magma activity as soon as possible,” said Sumino. “Now we are developing a portable mass spectrometer for on-site, real-time monitoring of noble gas isotope ratios from fumarolic gases. Our next step is to establish a noble gas analysis protocol with this new instrument, to make it a reality that all active volcanoes — at least those which have the potential to cause disaster to local residents — are monitored 24 hours a day, seven days a week.”
Reference:
Tomoya Obase, Hirochika Sumino, Kotaro Toyama, Kaori Kawana, Kohei Yamane, Muga Yaguchi, Akihiko Terada, Takeshi Ohba. Monitoring of magmatic–hydrothermal system by noble gas and carbon isotopic compositions of fumarolic gases. Scientific Reports, 2022; 12 (1) DOI: 10.1038/s41598-022-22280-3
Field area and glacier retreat due to calving. (A) Location of Börgen Bay at the West Antarctic Peninsula. Bathymetry from ETOPO 1 global relief model (74). (B) Bathymetry of Börgen Bay from multibeam echosounder data and coastline/topography from Landsat imagery (see Materials and Methods). Dots mark locations of conductivity-temperature-depth (CTD) profiles used here, with profiles taken before (red) and after (blue) the calving event. (C) Landsat images of the William Glacier front from (top) 17 January 2020 and (bottom) 24 January 2020. In both panels, the orange line marks the glacier front on 17 January 2020 to highlight the retreat of the glacier between those dates. Credit: Science Advances (2022). DOI: 10.1126/sciadv.add0720
Scientists on a research vessel in Antarctica watched the front of a glacier disintegrate and their measurements “went off the scale.” As well as witnessing disruptions on the ocean surface, they recorded “internal” underwater tsunamis as tall as a house, a phenomenon that has been previously missed in the understanding of ocean mixing and in computer models.
The team, led by British Antarctic Survey (BAS) researchers, report their observations today in the journal Science Advances.
Internal tsunamis are an important factor in ocean mixing, which affects life in the ocean, temperatures at different depths, and how much ice the ocean can melt. Ice in Antarctica flows to the coast along glacier-filled valleys. While some ice melts into the ocean, much breaks off into icebergs, which range in size from small chunks up to the size of a country.
A team on board the BAS research ship RRS James Clark Ross was taking ocean measurements close to the William Glacier, situated on the Antarctic Peninsula, as the front of it dramatically disintegrated into thousands of small pieces.
The William Glacier typically has one or two large calving events per year, and the team estimated this one broke off around 78,000 square meters of ice—around the area of 10 football pitches—with the front of the glacier towering 40 meters above sea level.
Before it broke away, the water temperature was cooler at around 50-100 meters in depth, and warmer below this. After the calving, this changed dramatically, with temperature much more even across different depths.
Lead author of the study Professor Michael Meredith, head of the Polar Oceans team at BAS, said, “This was remarkable to see, and we were lucky to be in the right place at the right time. Lots of glaciers end in the sea, and their ends regularly split off into icebergs. This can cause big waves at the surface but we know now it also creates waves inside the ocean. When they break, these internal waves cause the sea to mix and this affects life in the sea, how warm it is at different depths and how much ice it can melt. This is important for us to understand better.
“Ocean mixing influences where nutrients are in the water and that matters for ecosystems and biodiversity. We thought we knew what caused this mixing—in summer, we thought it was mainly wind and tides, but it never occurred to us that iceberg calving could cause internal tsunamis that would mix things up so substantially.”
Professor James Scourse, Head of the Department of Earth and Environmental Sciences at the University of Exeter, was Principal Scientific Officer on the RRS James Clark Ross at the time of the calving event, which was captured by a Sky News team on board at the time.
Two other scientists from Exeter have been central to the interpretation of the data captured, Dr. Katy Sheen and Ph.D. student Tobias Ehmen of the Centre for Geography and Environmental Science on the Penryn Campus.
“Often the most important and exciting discoveries in science are serendipitous—you happen to be at the right place at the right time with the right instruments and the right people—and because you know it’s important you just make sure you tweak the work plan to make the most of what nature has offered you,” Professor Scourse said. “We did that in Börgen Bay back in January 2020 and as a result we’ve produced the first data on a process that has implications for how fast the ocean is able to melt the ice sheets. This has implications for all of us.”
As opposed to the waves caused by wind and tides, tsunamis are caused by geophysical events where water is suddenly shifted, for example, by an earthquake or landslide.
Internal tsunamis have been noticed in a handful of places, caused by landslides. Until now, no one had noticed that they are happening around Antarctica, probably all the time because of the thousands of calving glaciers there. Other places with glaciers are likely affected also, including Greenland and elsewhere in the Arctic.
This chance observation and understanding is important, as glaciers are set to retreat and calve more as global warming continues. This could likely increase the number of internal tsunamis created and the mixing they cause.
This process is not factored into current computer models enabling us to predict what might happen around Antarctica. This discovery changes our understanding of how the ocean around Antarctica is mixed and will improve knowledge about what it means for climate, the ecosystem and sea level rise.
Professor Meredith remarked, “Our fortuitous timing shows how much more we need to learn about these remote environments and how they matter for our planet.”
Reference:
Michael P. Meredith et al, Internal tsunamigenesis and ocean mixing driven by glacier calving in Antarctica, Science Advances (2022). DOI: 10.1126/sciadv.add0720
Giant sea scorpions once roamed the ancient Devonian sea 400 million years ago. Now, researchers are learning more about that world. Credit: Aunt Spray | Shutterstock.com
Trapped for millennia, the tiniest liquid remnants of an ancient inland sea have now been revealed. The surprising discovery of seawater sealed in what is now North America for 390 million years opens up a new avenue for understanding how oceans change and adapt with the changing climate. The method may also be useful in understanding how hydrogen can be safely stored underground and transported for use as a carbon-free fuel source.
“We discovered we can actually dig out information from these mineral features that could help inform geologic studies, such as the seawater chemistry from ancient times,” said Sandra Taylor, first author of the study and a scientist at the Department of Energy’s Pacific Northwest National Laboratory.
Taylor worked with PNNL colleagues Daniel Perea, John Cliff, and Libor Kovarik to perform the analyses in collaboration with geochemists Daniel Gregory of the University of Toronto and Timothy Lyons of the University of California, Riverside. The research team reported their discovery in the December 2022 issue of Earth and Planetary Science Letters.
Many types of minerals and gems contain small pockets of trapped liquid. Indeed, some gemstones are prized for their light-catching bubbles of liquid trapped within. What’s different in this study is that scientists were able to reveal what was inside the tiniest water pockets, using advanced microscopy and chemical analyses.
The findings of the study confirmed that the water trapped inside the rock fit the chemistry profile of the ancient inland saltwater sea that once occupied upstate New York, where the rock originated. During the Middle Devonian period, this inland sea stretched from present day Michigan to Ontario, Canada. It harbored a coral reef to rival Australia’s Great Barrier Reef. Sea scorpions the size of a pickup truck patrolled waters that harbored now-extinct creatures like trilobites, and the earliest examples of horseshoe crabs.
But eventually the climate changed, and along with that change, most of the creatures and the sea itself disappeared, leaving behind only fossil remains embedded in sediments that eventually became the pyrite rock sample used in the current experiment.
Clues to an ancient climate and to climate change
Scientists use rock samples as evidence to piece together how the climate has changed over the long span of geologic time.
“We use mineral deposits to estimate the temperature of the ancient oceans,” said Gregory, a geologist at the University of Toronto, and one of the study leaders. But there are relatively few useful examples in the geological record.
“Salt deposits from trapped seawater [halite] are relatively rare in the rock record, so there are millions of years missing in the records and what we currently know is based on a few localities where there is halite found,” Gregory said. By contrast, pyrite is found everywhere. “Sampling with this technique could open up millions of years of the geologic record and lead to new understanding of changing climate.”
Seawater surprise
The research team was trying to understand another environmental issue — toxic arsenic leaching from rock — when they noticed the tiny defects. Scientists describe the appearance of these particular pyrite minerals as framboids — derived from the French word for raspberry — because they look like clusters of raspberry segments under the microscope.
“We looked at these samples through the electron microscope first, and we saw these kind of mini bubbles or mini features within the framboid and wondered what they were,” Taylor said.
Using the precise and sensitive detection techniques of atom probe tomography and mass spectrometry — which can detect minuscule amounts of elements or impurities in minerals — the team worked out that the bubbles indeed contained water and their salt chemistry matched that of ancient seas.
From ancient sea to modern energy storage
These types of studies also have the potential to provide interesting insights into how to safely store hydrogen or other gases underground.
“Hydrogen is being explored as a low-carbon fuel source for various energy applications. This requires being able to safely retrieve and store large-amounts of hydrogen in underground geologic reservoirs. So it’s important to understand how hydrogen interacts with rocks,” said Taylor. “Atom probe tomography is one of the few techniques where you can not only measure atoms of hydrogen, but you can actually see where it goes in the mineral. This study suggests that tiny defects in minerals might be potential traps for hydrogen. So by using this technique we could figure out what’s going on at the atomic level, which would then help in evaluating and optimizing strategies for hydrogen storage in the subsurface.”
This research was conducted at EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility at PNNL. Lyons and Gregory applied to use the facility through a competitive application process. The research was also supported by a grant from the Natural Sciences and Engineering Research Council of Canada.
Reference:
S.D. Taylor, D.D. Gregory, D.E. Perea, L. Kovarik, J.B. Cliff, T.W. Lyons. Pushing the limits: Resolving paleoseawater signatures in nanoscale fluid inclusions by atom probe tomography. Earth and Planetary Science Letters, 2022; 599: 117859 DOI: 10.1016/j.epsl.2022.117859
A dazzling play of colors highlights Southern California’s long lost clam. Photo Credit: Jeff Goddard
Discovering a new species is always exciting, but so is finding one alive that everyone assumed had been lost to the passage of time. A small clam, previously known only from fossils, has recently been found living at Naples Point, just up the coast from UC Santa Barbara. The discovery appears in the journal Zookeys.
“It’s not all that common to find alive a species first known from the fossil record, especially in a region as well-studied as Southern California,” said co-author Jeff Goddard, a research associate at UC Santa Barbara’s Marine Science Institute. “Ours doesn’t go back anywhere near as far as the famous Coelacanth or the deep-water mollusk Neopilina galatheae — representing an entire class of animals thought to have disappeared 400 million years ago — but it does go back to the time of all those wondrous animals captured by the La Brea Tar Pits.”
On an afternoon low tide in November 2018, Goddard was turning over rocks searching for nudibranch sea slugs at Naples Point, when a pair of small, translucent bivalves caught his eye. “Their shells were only 10 millimeters long,” he said. “But when they extended and started waving about a bright white-striped foot longer than their shell, I realized I had never seen this species before.” This surprised Goddard, who has spent decades in California’s intertidal habitats, including many years specifically at Naples Point. He immediately stopped what he was doing to take close-up photos of the intriguing animals.
With quality images in hand, Goddard decided not to collect the animals, which appeared to be rare. After pinning down their taxonomic family, he sent the images to Paul Valentich-Scott, curator emeritus of malacology at the Santa Barbara Museum of Natural History. “I was surprised and intrigued,” Valentich-Scott recalled. “I know this family of bivalves (Galeommatidae) very well along the coast of the Americas. This was something I’d never seen before.”
He mentioned a few possibilities to Goddard, but said he’d need to see the animal in-person to make a proper assessment. So, Goddard returned to Naples Point to claim his clam. But after two hours combing just a few square meters, he still hadn’t caught sight of his prize. The species would continue to elude him many more times.
Nine trips later, in March 2019, and nearly ready to give up for good, Goddard turned over yet another rock and saw the needle in the haystack: A single specimen, next to a couple of small white nudibranchs and a large chiton. Valentich-Scott would get his specimen at last, and the pair could finally set to work on identification.
Valentich-Scott was even more surprised once he got his hands on the shell. He knew it belonged to a genus with one member in the Santa Barbara region, but this shell didn’t match any of them. It raised the exciting possibility that they had found a new species.
“This really started ‘the hunt’ for me,” Valentich-Scott said. “When I suspect something is a new species, I need to track back through all of the scientific literature from 1758 to the present. It can be a daunting task, but with experience it can go pretty quickly.”
The two researchers decided to check out an intriguing reference to a fossil species. They tracked down illustrations of the bivalve Bornia cooki from the paper describing the species in 1937. It appeared to match the modern specimen. If confirmed, this would mean that Goddard had found not a new species, but a sort of living fossil.
It is worth noting that the scientist who described the species, George Willett, estimated he had excavated and examined perhaps 1 million fossil specimens from the same location, the Baldwin Hills in Los Angeles. That said, he never found B. cooki himself. Rather, he named it after Edna Cook, a Baldwin Hills collector who had found the only two specimens known.
Valentich-Scott requested Willett’s original specimen (now classified as Cymatioa cooki) from the Natural History Museum of Los Angeles County. This object, called the “type specimen,” serves to define the species, so it’s the ultimate arbiter of the clam’s identification.
Meanwhile, Goddard found another specimen at Naples Point — a single empty shell in the sand underneath a boulder. After carefully comparing the specimens from Naples Point with Willett’s fossil, Valentich-Scott concluded they were the same species. “It was pretty remarkable,” he recalled.
Small size and cryptic habitat notwithstanding, all of this begs the question of how the clam eluded detection for so long. “There is such a long history of shell-collecting and malacology in Southern California — including folks interested in the harder to find micro-mollusks — that it’s hard to believe no one found even the shells of our little cutie,” Goddard said.
He suspects the clams may have arrived here on currents as planktonic larvae, carried up from the south during marine heatwaves from 2014 through 2016. These enabled many marine species to extend their distributions northward, including several documented specifically at Naples Point. Depending on the animal’s growth rate and longevity, this could explain why no one had noticed C. cooki at the site prior to 2018, including Goddard, who has worked on nudibranchs at Naples Point since 2002.
“The Pacific coast of Baja California has broad intertidal boulder fields that stretch literally for miles,” Goddard said, “and I suspect that down there Cymatioa cooki is probably living in close association with animals burrowing beneath those boulders.
Reference:
Paul Valentich-Scott, Jeffrey H. R. Goddard. A fossil species found living off southern California, with notes on the genus Cymatioa (Mollusca, Bivalvia, Galeommatoidea). ZooKeys, 2022; 1128: 53 DOI: 10.3897/zookeys.1128.95139
Impressions of the Ediacaran fossils Dickinsonia (at center) with the smaller anchor shaped Parvancorina (left) in sandstone of the Ediacara Member from the Nilpena Ediacara National Park in South Australia. Photo courtesy of Scott Evans.
A new study by Virginia Tech geobiologists traces the cause of the first known mass extinction of animals to decreased global oxygen availability, leading to the loss of a majority of animals present near the end of the Ediacaran Period some 550 million years ago.
The research spearheaded by Scott Evans, a postdoctoral researcher in the Department of Geosciences, part of the Virginia Tech College of Science, shows this earliest mass extinction of about 80 percent of animals across this interval. “This included the loss of many different types of animals, however those whose body plans and behaviors indicate that they relied on significant amounts of oxygen seem to have been hit particularly hard,” Evans said. “This suggests that the extinction event was environmentally controlled, as are all other mass extinctions in the geologic record.”
Evans’ work was published Nov. 7 in the Proceedings of the National Academy of Sciences, a peer-reviewed journal of the National Academy of Sciences. The study was co-authored by Shuhai Xiao, also a professor in the Department of Geosciences, and several researchers led by Mary Droser from the University of California Riverside’s Department of Earth and Planetary Sciences, where Evans earned his master’s degree and Ph.D.
“Environmental changes, such as global warming and deoxygenation events, can lead to massive extinction of animals and profound disruption and reorganization of the ecosystem,” said Xiao, who is an affiliated member of the Global Change Center, part of the Virginia Tech Fralin Life Sciences Institute. “This has been demonstrated repeatedly in the study of Earth history, including this work on the first extinction documented in the fossil record. This study thus informs us about the long-term impact of current environmental changes on the biosphere.”
What exactly caused the drop in global oxygen? That’s still up for debate. “The short answer to how this happened is we don’t really know,” Evans said. “It could be any number and combination of volcanic eruptions, tectonic plate motion, an asteroid impact, etc., but what we see is that the animals that go extinct seem to be responding to decreased global oxygen availability.”
The study by Evans and Xiao is timelier than one would think. In an unconnected study, Virginia Tech scientists recently found that anoxia, the loss of oxygen availability, is affecting the world’s fresh waters. The cause? The warming of waters brought on by climate change and excess pollutant runoff from land use. Warming waters diminish fresh water’s capacity to hold oxygen, while the breakdown of nutrients in runoff by freshwater microbes gobbles up oxygen.
“Our study shows that, as with all other mass extinctions in Earth’s past, this new, first mass extinction of animals was caused by major climate change — another in a long list of cautionary tales demonstrating the dangers of our current climate crisis for animal life,” said Evans, who is an Agouron Institute Geobiology fellow.
Some perspective: The Ediacaran Period spanned roughly 96 million years, bookended on either side by the end of Cryogenian Period — 635 million years ago — and the beginning of the Cambrian Period — 539 million years ago. The extinction event comes just before a significant break in the geologic record, from the Proterozoic Eon to the Phanerozoic Eon.
There are five known mass extinctions that stand out in the history of animals, the “Big Five,” according to Xiao, including the Ordovician-Silurian Extinction (440 million years ago), the late Devonian Extinction (370 million years ago), the Permian-Triassic Extinction (250 million years ago), the Triassic-Jurassic Extinction (200 million years ago), and the Cretaceous-Paleogene Extinction (65 million years ago).
“Mass extinctions are well recognized as significant steps in the evolutionary trajectory of life on this planet,” Evans and team wrote in the study. Whatever the instigating cause of the mass extinction, the result was multiple major shifts in environmental conditions. “Particularly, we find support for decreased global oxygen availability as the mechanism responsible for this extinction. This suggests that abiotic controls have had significant impacts on diversity patterns throughout the more than 570 million-year history of animals on this planet,” the authors wrote.
Fossil imprints in rock tell researchers how the creatures that perished in this extinction event would have looked. And they looked, in Evans’ words, “weird.”
“These organisms occur so early in the evolutionary history of animals that in many cases they appear to be experimenting with different ways to build large, sometimes mobile, multicellular bodies,” Evans said. “There are lots of ways to recreate how they look, but the take-home is that before this extinction the fossils we find don’t often fit nicely into the ways we classify animals today. Essentially, this extinction may have helped pave the way for the evolution of animals as we know them.”
The study, like scores of other recent publications, came out of the COVID-19 pandemic. Because Evans, Xiao, and their team couldn’t get access to the field, they decided to put together a global database based mostly on published records to test ideas about changing diversity. “Others had suggested that there might be an extinction at this time, but there was a lot of speculation. So we decided to put together everything we could to try and test those ideas.” Evans said. Much of the data used in the study was collected by Droser and several graduate students from the University of California Riverside.
Reference:
Scott D. Evans, Chenyi Tu, Adriana Rizzo, Rachel L. Surprenant, Phillip C. Boan, Heather McCandless, Nathan Marshall, Shuhai Xiao, Mary L. Droser. Environmental drivers of the first major animal extinction across the Ediacaran White Sea-Nama transition. Proceedings of the National Academy of Sciences, 2022; 119 (46) DOI: 10.1073/pnas.2207475119
SMU paleontologists helped find a new species of pterosaurs in Angola, where fossils of other large marine animals have been found. E. otyikokolo can be seen flying above the ocean in the ancient picture. Artwork by Karen Carr Studio.
With wings spanning nearly 16 feet, a new species of pterosaurs has been identified from the Atlantic coast of Angola.
An international team, including two vertebrate paleontologists from SMU, named the new genus and species Epapatelo otyikokolo. This flying reptile of the dinosaur age was found in the same region of Angola as fossils from large marine animals currently on display at the Smithsonian’s National Museum of Natural History.
Pterosaur fossils that date back to the Late Cretaceous are extremely rare in sub-Saharan Africa, said team member Michael J. Polcyn, research associate in the Huffington Department of Earth Sciences and senior research fellow, ISEM at SMU (Southern Methodist University).
“This new discovery gives us a much better understanding of the ecological role of the creatures that were flying above the waves of Bentiaba, on the west coast of Africa, approximately 71.5 million years ago,” Polcyn said.
Renowned paleontologist Louis L. Jacobs, SMU professor emeritus of earth sciences and president of ISEM, an interdisciplinary institute at the university, also collaborated on the research. The team’s findings were published in the journal Diversity.
Epapatelo otyikokolo is believed to have been a fish-eating pterosaur that behaved similarly to large modern-day seabirds.
“They likely spent time flying above open-water environments and diving to feed, like gannets and brown pelicans do today,” Jacobs said. “Epapatelo otyikokolo was not a small animal, and its wingspan was approximately 4.8 m, or nearly 16 feet.”
But fossils discovered since the study suggest that some of the newly identified pterosaur species could have been even larger creatures, Polcyn said. Pterosaurs were impressive creatures, with some of the largest species having wingspans of nearly 35 feet.
The genus name ‘Epapatelo’ is the translation of the word from the Angolan Nhaneca dialect meaning “wing,” and the species name “otyikokolo” is the translation of ‘lizard.’ The Nhaneca or Nyaneka people are an Indigenous group from Angola’s Namibe Province, the region where the fossils were found.
The lead author of the study was Alexandra E. Fernandes, of Museu da Lourinhã, Universidade NOVA de Lisboa and The Bavarian State Collection for Paleontology and Geology. Other co-authors include Octávio Mateus of Universidade NOVA de Lisboa and Museu da Lourinhã; Brian Andres of the University of Sheffield; Anne S. Schulp of the Naturalis Biodiversity Center and Utrecht University in the Netherlands; and Antonio Olímpio Gonçalves of the Universidade Agostinho Neto in Angola.
Jacobs and Polcyn forged the Projecto PaleoAngola partnership with collaborators in Angola, Portugal, and the Netherlands to explore and excavate Angola’s rich fossil history, and began laying the groundwork for returning the fossils to the West African nation. Back in Dallas, Jacobs, Polcyn, and research associate Diana Vineyard went to work over a period of 13 years with a small army of SMU students to prepare the fossils excavated by Projecto PaleoAngola.
This international team discovered and collected the fourteen bones from Epapatelo otyikokolo in Bentiaba, Angola, starting in 2005. Bentiaba is located on a section of Angola coastline that Jacobs has called a “museum in the ground” because so many fossils have been found in the rocks there.
Many of those fossils are currently on display at the Smithsonian’s National Museum of Natural History “Sea Monsters Unearthed” exhibit, which was co-produced with SMU. It features large marine reptiles from the Cretaceous Period — mosasaurs, turtles, and plesiosaurs.
Reference:
Alexandra E. Fernandes, Octávio Mateus, Brian Andres, Michael J. Polcyn, Anne S. Schulp, António Olímpio Gonçalves, Louis L. Jacobs. Pterosaurs from the Late Cretaceous of Angola. Diversity, 2022; 14 (9): 741 DOI: 10.3390/d14090741
Interactions of mantles at different depths. Credit: Prof. Dai Liqun’s team.
Recently, a research team led by Prof. Dai Liqun from the University of Science and Technology of China (USTC) of the Chinese Academy of Science (CAS), has revealed that the mantle sources of Cenozoic and Mesozoic mafic igneous rocks from the eastern North China craton had gone through different types of metasomatism at different depths by comparing the composition of molybdenum isotopes. Their work was published in Geology.
Subducting slabs precipitate fluids with different compositions and properties at different depths, and when interacting with mantle wedge rocks, metasomatism occurs near the interface due to significant difference in physical condition and composition. Such metasomatism changes the chemical composition of mantle wedge rocks and produces different types of magmatism. By determining the composition of magmatic rock, researchers can study the interaction of mantles at different depths, therefore revealing the structure of the subduction zone.
DAI’s team compared the composition of molybdenum isotopes in the Mesozoic-Cenozoic mafic igneous rock in the eastern North China craton and discovered a systematic difference, indicating a difference in molybdenum isotopes composition in the fluids derived in the subducting oceanic slabs at subarc and postarc depths.
The team also discovered that Mesozoic mafic igneous rocks have island-arc basalt-like features and a heavier molybdenum isotopes composition than regular mantles, indicating that they came from subducting oceanic slab-derived fluids at subarc depths in a small mantle wedge. In contrast, Cenozoic mafic igneous rocks show oncean-island basalt-like features and have lighter molybdenum isotopes than regular mantles, coming from dehydrated slab-derived melts at postarc depths in a large mantle wedge.
The difference in molybdenum isotopes composition with rutile stability at different depths was explained. Molybdenum in subducting slabs was mainly hosted in mineral rutile, which was stable at subarc depths but broke down at postarc depth. Moreover, by combining the research on Sr-Nd isotopes with that on Mo isotopes, the team further verified that the mantle source of Mesozoic and Cenozoic mafic igneous rock had gone through different types of metasomatism at different depths.
This work provided an effective method to study the interaction of mantles at different depths, which can help the understanding of subduction zone structure in the future.
Reference:
Wei Fang et al, Molybdenum isotopes in mafic igneous rocks record slab-mantle interactions from subarc to postarc depths, Geology (2022). DOI: 10.1130/G50456.1
Artist’s reconstruction of Gangtoucunia aspera as it would have appeared in life on the Cambrian seafloor, circa 514 million years ago. The individual in the foreground has part of the skeleton removed to show the soft polyp inside the skeleton. Reconstruction by Xiaodong Wang.
An exceptionally well-preserved collection of fossils discovered in eastern Yunnan Province, China, has enabled scientists to solve a centuries-old riddle in the evolution of life on earth, revealing what the first animals to make skeletons looked like. The results have been published today in Proceedings of the Royal Society B.
The first animals to build hard and robust skeletons appear suddenly in the fossil record in a geological blink of an eye around 550-520 million years ago during an event called the Cambrian Explosion. Many of these early fossils are simple hollow tubes ranging from a few millimetres to many centimetres in length. However, what sort of animals made these skeletons was almost completely unknown, because they lack preservation of the soft parts needed to identify them as belonging to major groups of animals that are still alive today.
The new collection of 514 million year old fossils includes four specimens of Gangtoucunia aspera with soft tissues still intact, including the gut and mouthparts. These reveal that this species had a mouth fringed with a ring of smooth, unbranched tentacles about 5 mm long. It’s likely that these were used to sting and capture prey, such as small arthropods. The fossils also show that Gangtoucunia had a blind-ended gut (open only at one end), partitioned into internal cavities, that filled the length of the tube.
These are features found today only in modern jellyfish, anemones and their close relatives (known as cnidarians), organisms whose soft parts are extremely rare in the fossil record. The study shows that these simple animals was among the first to build the hard skeletons that make up much of the known fossil record.
According to the researchers, Gangtoucunia would have looked similar to modern scyphozoan jellyfish polyps, with a hard tubular structure anchored to the underlying substrate. The tentacle mouth would have extended outside the tube, but could have been retracted inside the tube to avoid predators. Unlike living jellyfish polyps however, the tube of Gangtoucunia was made of calcium phosphate, a hard mineral that makes up our own teeth and bones. Use of this material to build skeletons has become more rare among animals over time.
Corresponding author Dr Luke Parry, Department of Earth Sciences, University of Oxford, said: ‘This really is a one-in-million discovery. These mysterious tubes are often found in groups of hundreds of individuals, but until now they have been regarded as ‘problematic’ fossils, because we had no way of classifying them. Thanks to these extraordinary new specimens, a key piece of the evolutionary puzzle has been put firmly in place.’
The new specimens clearly demonstrate that Gangtoucunia was not related to annelid worms (earthworms, polychaetes and their relatives) as had been previously suggested for similar fossils. It is now clear that Gangtoucunia’s body had a smooth exterior and a gut partitioned longitudinally, whereas annelids have segmented bodies with transverse partitioning of the body.
The fossil was found at a site in the Gaoloufang section in Kunming, eastern Yunnan Province, China. Here, anaerobic (oxygen-poor) conditions limit the presence of bacteria that normally degrade soft tissues in fossils.
PhD student Guangxu Zhang, who collected and discovered the specimens, said: ‘The first time I discovered the pink soft tissue on top of a Gangtoucunia tube, I was surprised and confused about what they were. In the following month, I found three more specimens with soft tissue preservation, which was very exciting and made me rethink the affinity of Gangtoucunia. The soft tissue of Gangtoucunia, particularly the tentacles, reveals that it is certainly not a priapulid-like worm as previous studies suggested, but more like a coral, and then I realised that it is a cnidarian.’
Although the fossil clearly shows that Gangtoucunia was a primitive jellyfish, this doesn’t rule out the possibility that other early tube-fossil species looked very different. From Cambrian rocks in Yunnan province, the research team have previously found well-preserved tube fossils that could be identified as priapulids (marine worms), lobopodians (worms with paired legs, closely related to arthropods today) and annelids.
Co-corresponding author Xiaoya Ma (Yunnan University and University of Exeter) said: ‘A tubicolous mode of life seems to have become increasingly common in the Cambrian, which might be an adaptive response to increasing predation pressure in the early Cambrian. This study demonstrates that exceptional soft-tissue preservation is crucial for us to understand these ancient animals.’
Reference:
Guangxu Zhang, Luke A. Parry, Jakob Vinther, Xiaoya Ma. Exceptional soft tissue preservation reveals a cnidarian affinity for a Cambrian phosphatic tubicolous enigma. Proceedings of the Royal Society B: Biological Sciences, 2022; 289 (1986) DOI: 10.1098/rspb.2022.1623
