Spectacular fossil plants preserved within a volcanic ash fall in China have shed light on an evolutionary race 300 million years ago, which was eventually won by the seed-bearing plants that dominate so much of the Earth today.

New research into fossils found at the ‘Pompeii of prehistoric plants’, in Wuda, Inner Mongolia, reveals that the plants, called Noeggerathiales, were highly-evolved members of the lineage from which came seed plants.

Noeggerathiales were important peat-forming plants that lived around 325 to 251 million years ago. Understanding their relationships to other plant groups has been limited by poorly preserved examples until now.

The fossils found in China have allowed experts to work out that Noeggerathiales are more closely related to seed plants than to other fern groups.

No longer considered an evolutionary dead-end, they are now recognized as advanced tree-ferns that evolved complex cone-like structures from modified leaves. Despite their sophistication, Noeggerathiales fell victim to the profound environmental and climate changes of 251 million years ago that destroyed swamp ecosystems globally.

The international research team, led by palaeontologists at Nanjing Institute of Geology and Palaeontology and the University of Birmingham, today published its findings in the Proceedings of the National Academy of Sciences (PNAS).

Co-author Dr. Jason Hilton, Reader in Palaeobiology at the University of Birmingham’s Institute of Forest Research, commented: “Noeggerathiales were recognized as early as the 1930s, but scientists have treated them as a ‘taxonomic football’, endlessly kicked around without anyone identifying their place in the Story of Life.

“The spectacular fossil plants found in China are becoming renowned as the plant equivalent of Pompeii. Thanks to this slice of life preserved in volcanic ash, we were able to reconstruct a new species of Noeggerathiales that finally settles the group’s affinity and evolutionary importance.

“The fate of the Noeggerathiales is a stark reminder of what can happen when even very advanced life forms are faced with rapid environmental change.”

The researchers studied complete Noeggerathiales preserved in a bed of volcanic ash 66 cm thick formed 298 million years ago, smothering all the plants growing in a nearby swamp.

The ash stopped the fossils from rotting or being consumed, and preserved many complete individuals in microscopic detail.

Lead-Author Jun Wang, Professor of Palaeobotany at Nanjing Institute of Geology and Palaeontology, commented: “Many specimens were identified in excavations in 2006-2007 when a few leaves were visible on the surface of the ash. It looked they might be connected to each other and a stem below — we revealed the crown on site, but then extracted the specimens complete to take them back to the lab.

“It has taken many years to study these fully and the additional specimens we have found more recently. The complete trees are the most impressive fossil plants I have seen and because of our careful work they are also some of the most important to science.”

The researchers also deduced that that the ancestral lineage from which seed plants evolved diversified alongside the earliest seed plant radiation during the Devonian, Carboniferous and Permian periods, and did not rapidly die out as previously thought.

Reference:
Jun Wang, Jason Hilton, Hermann W. Pfefferkorn, Shijun Wang, Yi Zhang, Jiri Bek, Josef Pšenička, Leyla J. Seyfullah, David Dilcher. Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation. Proceedings of the National Academy of Sciences, 2021; 118 (11): e2013442118 DOI: 10.1073/pnas.2013442118

Note: The above post is reprinted from materials provided by University of Birmingham.

Some of Australia’s most famous animals—wombat, platypus, kangaroos and the extinct marsupial tiger thylacine—have been traced back to their fossil ancestors in remarkable finds in central South Australia.

Now a remote expedition to a large inland salt lake in 2017 has sifted through remains unearthed in Namba Formation deposits to describe a tiny new skink, an ancestor of Australia’s well-known bluetongue lizards—to be named in honor of world-renown Flinders University lizard researcher Professor Mike Bull.

The new species, unveiled in the Royal Society’s Open Science today, is described as Australia’s oldest—a 25 million-year-old skink named Proegernia mikebulli after the late Flinders University Professor Mike Bull.

It was found by Flinders University and South Australian Museum palaeontologists and volunteers at a rich fossil site on Lake Pinpa located on the 602,000 square hectare Frome Downs Station, seven hours drive north of capital city Adelaide.

Following the crusted shoreline of a salt lake, the team homed in on a cross section of sediments where fossil excavations of ancestors of koala, a predatory bird, and fragments of a thylacine were previously unearthed. Remains of prehistoric fish, platypus, dolphins and crocodilians have also been found nearby.

“It was 45 C in the shade that day and hard work digging through the clay, but it was definitely worth it once the tiniest of bone fragments turned out to be those of the oldest Australian skink,” says lead author palaeo-herpetologist Dr. Kailah Thorn, who conducted the research at Flinders University as part of her Ph.D.

The once-verdant interior of Australia is considered the cradle of Australia’s unique fauna and in particular its reptile diversity.

“Fossil lizards are often too small to be identified when you’re in the field. Lizard skulls are made of more than 20 individual bones that all disarticulate when they fossilize,” says Dr. Thorn, who now works as curator of the Edward de Courcy Clarke Earth Sciences Museum at the University of Western Australia.

The discovery of the tiny fossil lizards in an area the size of one million soccer fields was enabled by building an understanding of the geology of the region, and targeting fossiliferous bands of silt to thoroughly sieve and sort back at the lab, she explains.

“These lizard fossils owe their discovery to the patient sorting of tiny bones,” says lead author, vertebrate palaeontologist Flinders University Associate Professor Trevor Worthy. “A teaspoon holds hundreds of tiny bones—all revealed in translucent splendor under a microscope.”

“Once every 30 spoons something else is found among the fish—usually a tiny mammal tooth. But the 2017 discovery of the oldest skink was a golden moment for a palaentologist,” he says.

When researchers placed the fossil in the evolutionary tree of lizards, it was found to be an early member of the Australian skink subfamily Egerniinae—the group now encompassing bluetongues, sleepy lizards (shinglebacks), land mullets and spiny-tailed skinks.

The newly described lizard Proegernia mikebulli is named after the late Flinders University Professor Mike Bull, who passed away suddenly in late 2016.

Inspired generations of Australian herpetologists, Professor Bull’s wide-ranging research career centered on social skinks from the Egerniinae subfamily, their behavior, parasites, and conservation.

“Our colleague Professor Bull’s long-term ecological studies of sleepy lizards were a massive contribution to biology,” says co-author Matthew Flinders Professor Mike Lee (Flinders University / SA Museum).

“The fossil record is essentially data from a long-term natural ecological study, so its fitting that this fossil lizards is named after in honor of Mike.”

Reference:
A new species of Proegernia from the Namba Formation in South Australia and the early evolution and environment of Australian egerniine skinks, Royal Society Open Science, royalsocietypublishing.org/doi/10.1098/rsos.201686

Note: The above post is reprinted from materials provided by Flinders University.

Long held in a private collection, the newly analysed tooth of an approximately 9-year-old Neanderthal child marks the hominin’s southernmost known range. Analysis of the associated archaeological assemblage suggests Neanderthals used Nubian Levallois technology, previously thought to be restricted to Homo sapiens.

With a high concentration of cave sites harbouring evidence of past populations and their behaviour, the Levant is a major centre for human origins research. For over a century, archaeological excavations in the Levant have produced human fossils and stone tool assemblages that reveal landscapes inhabited by both Neanderthals and Homo sapiens, making this region a potential mixing ground between populations. Distinguishing these populations by stone tool assemblages alone is difficult, but one technology, the distinct Nubian Levallois method, is argued to have been produced only by Homo sapiens.

In a new study published in Scientific Reports, researchers from the Max Planck Institute for the Science of Human History teamed up with international partners to re-examine the fossil and archaeological record of Shukbah Cave. Their findings extend the southernmost known range of Neanderthals and suggest that our now-extinct relatives made use of a technology previously argued to be a trademark of modern humans. This study marks the first time the lone human tooth from the site has been studied in detail, in combination with a major comparative study examining the stone tool assemblage.

“Sites where hominin fossils are directly associated with stone tool assemblages remain a rarity — but the study of both fossils and tools is critical for understanding hominin occupations of Shukbah Cave and the larger region,” says lead author Dr Jimbob Blinkhorn, formerly of Royal Holloway, University of London and now with the Pan-African Evolution Research Group (Max Planck Institute for the Science of Human History).

Shukbah Cave was first excavated in the spring of 1928 by Dorothy Garrod, who reported a rich assemblage of animal bones and Mousterian-style stone tools cemented in breccia deposits, often concentrated in well-marked hearths. She also identified a large, unique human molar. However, the specimen was kept in a private collection for most of the 20th century, prohibiting comparative studies using modern methods. The recent re-identification of the tooth at the Natural History Museum in London has led to new detailed work on the Shukbah collections.

“Professor Garrod immediately saw how distinctive this tooth was. We’ve examined the size, shape and both the external and internal 3D structure of the tooth, and compared that to Holocene and Pleistocene Homo sapiens and Neanderthal specimens. This has enabled us to clearly characterise the tooth as belonging to an approximately 9 year old Neanderthal child,” says Dr. Clément Zanolli, from Université de Bordeaux. “Shukbah marks the southernmost extent of the Neanderthal range known to date,” adds Zanolli.

Although Homo sapiens and Neanderthals shared the use of a wide suite of stone tool technologies, Nubian Levallois technology has recently been argued to have been exclusively used by Homo sapiens. The argument has been made particularly in southwest Asia, where Nubian Levallois tools have been used to track human dispersals in the absence of fossils.

“Illustrations of the stone tool collections from Shukbah hinted at the presence of Nubian Levallois technology so we revisited the collections to investigate further. In the end, we identified many more artefacts produced using the Nubian Levallois methods than we had anticipated,” says Blinkhorn. “This is the first time they’ve been found in direct association with Neanderthal fossils, which suggests we can’t make a simple link between this technology and Homo sapiens.”

“Southwest Asia is a dynamic region in terms of hominin demography, behaviour and environmental change, and may be particularly important to examine interactions between Neanderthals and Homo sapiens,” adds Prof Simon Blockley, of Royal Holloway, University of London. “This study highlights the geographic range of Neanderthal populations and their behavioural flexibility, but also issues a timely note of caution that there are no straightforward links between particular hominins and specific stone tool technologies.”

“Up to now we have no direct evidence of a Neanderthal presence in Africa,” said Prof Chris Stringer of the Natural History Museum. “But the southerly location of Shukbah, only about 400 km from Cairo, should remind us that they may have even dispersed into Africa at times.”

Partnerships

Researchers involved in this study include scholars from the Max Planck Institute for the Science of Human History, Royal Holloway, University of London, the Université de Bordeaux, the Max Planck Institute for Chemical Ecology, the University of Malta, and the Natural History Museum, London. This work was supported by the Leverhulme trust (RPH-2017-087).

Reference:
James Blinkhorn, Clément Zanolli, Tim Compton, Huw S. Groucutt, Eleanor M. L. Scerri, Lucile Crété, Chris Stringer, Michael D. Petraglia & Simon Blockley. Nubian Levallois technology associated with southernmost Neanderthals. Scientific Reports, 2021 DOI: 10.1038/s41598-021-82257-6

Note: The above post is reprinted from materials provided by Max Planck Institute for the Science of Human History.

Every spring, phytoplankton blooms flourish across the ocean. The single-celled, photosynthetic organisms pull carbon dioxide from the atmosphere and produce oxygen—part of a carbon sequestration system known as the biological pump.

Widely used numerical and satellite-based models assume that primary production and net community production (or the net amount of carbon removed from the atmosphere through the biological pump) are greatest in ecosystems dominated by plankton larger than 20 micrometers, known as microplankton, and lowest in those dominated by plankton smaller than 2 micrometers, known as picoplankton. However, the role of plankton in between those sizes, known as nanoplankton, has largely been ignored. Now Juranek et al. show that nanoplankton may play a more significant role than previously thought.

The team studied the relationship between size and productivity in a region of the North Pacific Transition Zone (NPTZ), a subtropical-subpolar, basin-sized feature characterized by strong physical, chemical, and ecological gradients. The team members conducted three transects of the NPTZ in the spring or early summer of 2016, 2017, and 2019, crossing a feature known as the transition zone chlorophyll front, where net community production rates were as much as five times higher than those south of the transition zone.

The authors used a combination of approaches to characterize the size and diversity of plankton ranging from 0.5 to 100 micrometers in diameter. These measurements were compared to productivity rates determined both by an incubation-based method and by tracking the ratio of dissolved oxygen to argon in the seawater, which is related to net organic carbon production.

These coordinated data streams revealed a strong and previously unidentified link between variation in net community production and the biomass of nanoplankton. With additional insights from modeling, the authors suggest that both bottom-up factors, such as nutrient supply, and top-down factors, like size-specific grazing by predators, contribute to the importance of nanoplankton in the transition zone.

Models that fail to account for these middle-sized plankton may underestimate primary production and the efficiency of the biological pump, the researchers say. Understanding the role of nanoplankton will be critical as scientists work to understand how climate change may affect the carbon cycle in the future.

Reference:
Lauren W. Juranek et al. The Importance of the Phytoplankton “Middle Class” to Ocean Net Community Production, Global Biogeochemical Cycles (2020). DOI: 10.1029/2020GB006702

Note: The above post is reprinted from materials provided by American Geophysical Union.

Members of Syracuse University’s College of Arts and Sciences are shining new light on an enduring mystery — one that is millions of years in the making.

A team of paleontologists led by Professor Cathryn Newton has increased scientists’ understanding of whether Devonian marine faunas, whose fossils are lodged in a unit of bedrock in Central New York known as the Hamilton Group, were stable for millions of years before succumbing to waves of extinctions.

Drawing on 15 years of quantitative analysis with fellow professor Jim Brower (who died in 2018), Newton has continued to probe the structure of these ancient fossil communities, among the most renowned on Earth.

The group’s findings, reported by the Geological Society of America (GSA), provide critical new evidence for the unusual, long-term stability of these Devonian period communities.

Such persistence, Newton says, is a longstanding scientific enigma. She and her colleagues tested the hypothesis that these ancient communities displayed coordinated stasis — a theory that attempts to explain the emergence and disappearance of species across geologic time.

Newton and Brower, along with their student Willis Newman G’93, found that Devonian marine communities vary more in species composition than the theory predicts. Newton points out that they sought not to disprove coordinated stasis but rather to gain a more sophisticated understanding of when it is applicable. “Discovering more about the dynamics of these apparently stable Devonian communities is critical,” she says. “Such knowledge has immediate significance for marine community changes in our rapidly warming seas.”

Since geologist James Hall Jr. first published a series of volumes on the region’s Devonian fossils and strata in the 1840s, the Hamilton Group has become a magnet for research scientists and amateur collectors alike. Today, Central New York is frequently used to test new ideas about large-scale changes in Earth’s organisms and environments.

During Middle Devonian time (approximately 380-390 million years ago), the faunal composition of the region changed little over 4-6 million years. “It’s a significant amount for marine invertebrate communities to remain stable, or ‘locked,'” explains Newton, a professor in the Department of Earth and Environmental Sciences.

She, Brower and student researchers spent years examining eight communities of animals that once dwelled in a warm, shallow sea on the northern rim of the Appalachian Basin (which, eons ago, lay south of the equator). When the organisms died, sediment from the seafloor began covering their shells and exoskeletons. Minerals from the sediment gradually seeped into their remains, causing them to fossilize. The process also preserved many of them in living position, conserving original shell materials at some sites.

These fossils currently populate exposed bedrock throughout Central New York, ranging from soft, dark, deep-water shale to hard, species-rich, shelf siltstone. “Communities near the top of the bedrock exhibit more taxonomic and ecological diversity than those at the bottom,” Newton says. “We can compare the community types and composition through time. They are remarkable sites.”

Coordinated stasis has been a source of contention since 1995, when it was introduced. At the center of the dispute are two model-based explanations: environmental tracking and ecological locking.

Environmental tracking suggests that faunas follow their environment. “Here, periods of relative stasis are flanked by coordinated extinctions or regional disappearances. When the environment changes, so do marine faunas,” says Newton, also Professor of Interdisciplinary Sciences and Dean Emerita of Arts and Sciences.

Ecological locking, in contrast, views marine faunas as tightly structured communities, resistant to large-scale taxonomic change. Traditionally, this model has been used to describe the stability of lower Hamilton faunas.

Newton and her colleagues analyzed more than 80 sample sites, each containing some 300 specimens. Special emphasis was placed on the Cardiff and Pecksport Members, two rock formations in the Finger Lakes region that are part of the ancient Marcellus subgroup, famed for its natural gas reserves.

“We found that lower Hamilton faunas, with two exceptions, do not have clear counterparts among upper ones. Therefore, our quantitative tests do not support the ecological locking model as an explanation for community stability in these faunas,” she continues.

Newton considers this project a final tribute to Newman, a professor of biology at the State University of New York at Cortland, who died in 2014, and Brower, who fell seriously ill while the manuscript was being finalized. “Jim knew that he likely would not live to see its publication,” says Newton, adding that Brower died as the paper was submitted to GSA.

She says this new work extends and, in some ways, completes the team’s earlier research by further analyzing community structures in the Marcellus subgroup. “It has the potential to change how scientists view long-term stability in ecological communities.”

Reference:
Cathryn R. Newton, Willis B. Newman, James C. Brower. Quantitative paleoecology of marine faunas in the lower Hamilton Group (Middle Devonian, central New York): Significance for probing models of long-term community stability. GeoScience World, 2021 DOI: 10.1130/2020.2545(09)

Note: The above post is reprinted from materials provided by Syracuse University. Original written by Rob Enslin.

A newly discovered trace fossil of an ancient burrow has been named after University of Alberta paleontologist Murray Gingras. The fossil, discovered by a former graduate student, has an important role to play in gauging how salty ancient bodies of water were, putting together a clearer picture of our planet’s past.

“Naming the fossil after Gingras was a straightforward decision since his research focuses on tying modern observations of how salinity and substrate affect organism burrowing to ancient burrow appearance and species abundance trends.”

Trace fossils are a type of fossil that preserves activity of ancient life in the geological record. They include fossilized footprints, nests, droppings and, in this case, a fossilized burrow dug by an organism that lived in a watery environment.

The fossilized burrow, named Glossifungites gingrasi, is from the late Cretaceous of central Utah and was home to water-dwelling insects, similar to mayflies, more than 90 million years ago.

“Fossils like this are significant because they help us narrow down what type of organism dug the burrow — which in turn will tell us about the salinity of the water in which they lived,” said King.

Many organisms make use of burrows for shelter and protection while they feed. These animal-constructed sedimentary structures give researchers a clearer picture of biological communities and are important in understanding ancient rivers, bays, estuaries and oceans through their oxygenation levels and saltiness, King explained.

Murray Gingras, professor in the Department of Earth and Atmospheric Sciences, was the co-advisor for King’s doctoral studies and for the master’s degree of another researcher on the team, Andrew La Croix, now an assistant professor at the University of Waikato.

“I was surprised and honoured,” said Gingras of the recognition. “I have been recognized with a few different awards over the years, but nothing really came close to the pride and elation I felt when Ryan informed me that he and Andrew formally named a trace fossil for me.”

Reference:
M. Ryan King, Andrew D. La Croix, Terry A. Gates, Paul B. Anderson, Lindsay E. Zanno. Glossifungites gingrasi n. isp., a probable subaqueous insect domicile from the Cretaceous Ferron Sandstone, Utah. Journal of Paleontology, 2021; 1 DOI: 10.1017/jpa.2020.115

Note: The above post is reprinted from materials provided by University of Alberta. Original written by Andrew Lyle.