Together with colleagues from Belgium and the USA, Senckenberg scientist Gerald Mayr described a new fossil owl species. The skeleton of Primoptynx poliotauros is the oldest fossil of an owl preserved in such a state of completeness. The discovery provides unique insights into the lifestyle of the earliest owls. Unlike modern owls, the large extinct owl presumably did not kill its prey with its beak but with its talons, similar to goshawks and eagles. The study will be published today in the “Journal of Vertebrate Paleontology.”

Discoveries from the early stages of owl evolution are exceedingly rare. An approximately 60-million-year-old leg bone is the oldest fossil that can be assigned to an owl. “Other owls from this time period are also only known on the basis of individual bones and fragments. Therefore, I was especially pleased when I received a largely complete owl skeleton from the North American Willwood Formation for study, which my colleague and the study’s co-author, Philip Gingerich, had discovered 30 years ago,” explains Dr. Gerald Mayr of the Senckenberg Research Institute and Natural History Museum in Frankfurt, Germany.

The newly described animal belongs to a previously unknown, very large species of fossil owl. Except for the skull, all major bones of the 55-million-year-old bird are preserved. “The fossil owl was about the size of a modern Snowy Owl. However, it is clearly distinguished from all extant species by the different size of its talons. While in present-day owls the talons on all toes are approximately the same size, the newly described species Primoptynx poliotauros has noticeably enlarged talons on its hind toe and second toe,” explains Mayr.

These toe proportions are known from modern diurnal raptors, e.g., eagles and goshawks. These birds, which are not closely related to owls, pierce their prey with their sharp talons. Mayr and his colleagues therefore assume that the extinct owl also used its feet to kill its prey. “By contrast, present-day owls use their beak to kill prey items – thus, it appears that the lifestyle of this extinct owl clearly differed from that of its modern relatives,” adds the ornithologist from Frankfurt.

Moreover, the new discovery reveals a high level of diversity among the owls of the early Eocene in North America – from the small species Eostrix gulottai, measuring a mere 12 centimeters, to the newly discovered, roughly 60-centimeter-tall bird.

“It is not clear why owls changed their hunting technique in the course of their evolution. However, we assume that it may be related to the spread of diurnal birds of prey in the late Eocene and early Oligocene, approximately 34 million years ago. Competition for prey with diurnal birds of prey may have triggered feeding specializations in owls, possibly also leading to these charismatic birds’ nocturnal habits,” adds Mayr in closing.

Reference:
Mayr, G., Gingerich, P.D. and Smith, Th. (2020): Skeleton of a new owl from the early Eocene of North America (Aves, Strigiformes) with an accipitrid-like foot morphology. Journal of Vertebrate Paleontology, DOI: 10.1080/02724634.2020.1769116

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

In a study published today in the Nature journal Scientific Reports, Senckenberg scientist Mónica Solórzano-Kraemer defines specific time periods for the terms amber, copal, and resin. Together with researchers from the Universitat de Barcelona, the Instituto Geológico y Minero de España, and the University of Kansas, she also advocates the introduction of the term “defaunation resin.” These fossilizations, formed after 1760, fall into a time period significantly impacted by humans. They often provide the only direct opportunity to trace environmental changes and species loss.

Around the world, species go extinct every day—and the losses are particularly high in tropical areas such as the lowland forests. “These very landscapes were, and are, home to a large number of resin-producing trees,” explains Mónica Solórzano-Kraemer of the Senckenberg Research Institute and Natural History Museum in Frankfurt, and she continues, “In these resins, we can find animals that have been preserved over several hundreds, or even thousands, of years, thus giving us insights into a bygone, often no longer existing fauna.”

‘Defaunation resin’ is the name given to these fossilizations by Solórzano-Kraemer and her Spanish and American colleagues Xavier Delclòs, Enrique Peñalver, and Michael Engel in their recently published study. Defaunation refers to the loss of species and populations of wild animals, analog to the term deforestation for the loss of forests. From now on, this name is intended to be used for all resins that were formed after the year 1760. “With this, we want to establish a clear differentiation from the terms ‘copal’ and ‘amber,’ while at the same time emphasizing the importance of the young resins, which were deposited during an age massively influenced by humans,” adds the researcher from Frankfurt.

The chosen time period is oriented on the—as yet informal—Anthropocene epoch, which started with the onset of the industrial revolution and is characterized by deforestation, loss of species diversity, and additional environmental changes caused by humans. “Apart from historical collections, these comparatively young resins often provide the only opportunity to examine bygone ecosystems and to quantify the loss of species,” adds Solórzano-Kraemer.

For the term ‘copal,’ the team suggests an age classification between 2.58 million years ago and the year 1760; from now on, the term ‘amber’ is only to be used for fossilizations that are older than 2.58 million years. “This clear demarcation is very important for us to ensure comparability. Over 120 new species have been described from East African and Malagasy ‘copals’ alone, and many others will follow—we therefore need a uniform and succinct terminology that can be allocated to a specific time period,” adds Solórzano-Kraemer in conclusion.

Reference:
Mónica M. Solórzano-Kraemer et al. A revised definition for copal and its significance for palaeontological and Anthropocene biodiversity-loss studies, Scientific Reports (2020). DOI: 10.1038/s41598-020-76808-6

Note: The above post is reprinted from materials provided by Senckenberg Research Institute and Natural History Museum.

Fossil bones collected in the early 1990s on Henderson Island, part of the Pitcairn Group, have revealed a new species of Polynesian sandpiper.

The Henderson Sandpiper, a small wading bird that has been extinct for centuries, is described in an article in the Zoological Journal of the Linnean Society published last week.

The newly-described bird is formally named Prosobonia sauli after Cook Islands-based ornithologist and conservationist Edward K Saul.

A team of researchers from New Zealand, Australia, Denmark, Switzerland, the Netherlands and China, led by Canterbury Museum Research Curator Natural History Dr Vanesa De Pietri, described the Henderson Sandpiper from 61 fossilised bones cared for by the Natural History Museum at Tring in England.

Canterbury Museum Visiting Researcher Dr Graham Wragg collected the bones from caves and overhangs on Henderson Island in 1991 and 1992 during the Sir Peter Scott Commemorative Expedition to the Pitcairn Islands.

Prosobonia sauli is the fifth known species of Polynesian sandpiper. All but one of the species, the endangered Tuamotu Sandpiper (Prosobonia parvirostris), are extinct.

“We think Prosobonia sauli probably went extinct soon after humans arrived on Henderson Island, which archaeologists estimate happened no earlier than the eleventh century,” says Dr De Pietri.

“It’s possible these humans brought with them the Polynesian rat, which Polynesian sandpiper populations are very vulnerable to.”

DNA of the living Tuamotu Sandpiper and the extinct Tahiti Sandpiper (Prosobonia leucoptera), which is known only from a skin in the Naturalis Biodiversity Center in the Netherlands, was used to determine how Polynesian sandpipers are related to other wading birds.

“We found that Polynesian sandpipers are early-diverging members of a group that includes calidrine sandpipers and turnstones. They are unlike other sandpipers in that they are restricted to islands of the Pacific and do not migrate,” says Dr De Pietri.

Comparisons with the other two extinct Polynesian sandpiper species, the Kiritimati Sandpiper (Prosobonia cancellata) and the Mo’orea Sandpiper (Prosobonia ellisi), are complicated. These birds are known only from illustrations primarily by William Wade Ellis, an artist and Surgeon’s Mate on Captain James Cook’s third expedition, who probably saw the birds alive in the 1770s.

Compared to the Tuamotu Sandpiper, its geographically closest cousin, the Henderson Sandpiper had longer legs and a wider, straighter bill, indicating how it foraged for food. It probably adapted to the habitats available on Henderson Island, which are different to those on other islands where Polynesian sandpipers were found.

Henderson Island is the largest island in the Pitcairn Group, in the middle of the South Pacific Ocean. It has been uninhabited since around the fifteenth century and was designated a World Heritage Site by the United Nations in 1988.

Dr Paul Scofield, Canterbury Museum Senior Curator Natural History and one of the study’s co-authors, says Henderson Island is home to a number of unique species, a handful of which are landbirds like the Henderson Sandpiper.

“The island is really quite remarkable because every landbird species that lives there, or that we know used to live there, is not found anywhere else,” he says.

Dr De Pietri says the study shows the need to protect the one remaining Polynesian sandpiper species, the Tuamotu Sandpiper.

“We know that just a few centuries ago there were at least five Polynesian sandpiper species scattered around the Pacific. Now there’s only one, and its numbers are declining, so we need to ensure we look after the remaining populations.”

This research was supported by a grant from the Marsden Fund Council, managed by the Royal Society Te Ap?rangi, as well as the R S Allan Fund managed by Canterbury Museum.

Reference:
Vanesa L De Pietri, Trevor H Worthy, R Paul Scofield, Theresa L Cole, Jamie R Wood, Kieren J Mitchell, Alice Cibois, Justin J F J Jansen, Alan J Cooper, Shaohong Feng, Wanjun Chen, Alan Jd Tennyson, Graham M Wragg. A new extinct species of Polynesian sandpiper (Charadriiformes: Scolopacidae: Prosobonia) from Henderson Island, Pitcairn Group, and the phylogenetic relationships of Prosobonia. Zoological Journal of the Linnean Society, 2020; DOI: 10.1093/zoolinnean/zlaa115

Note: The above post is reprinted from materials provided by Canterbury Museum.

Arthropods have been among the most successful animals on Earth since the Cambrian Period, about 520 million years ago. They are the most familiar and ubiquitous, and constitute nearly 80% of all animal species today, far more than any other animals.

But how did arthropods evolve, and what did their ancestors look like? These have been a major conundrum in animal evolution puzzling generations of scientists for more than a century.

Now, researchers from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS) have discovered a shrimp-like fossil with five eyes, which has provided important insights into the early evolutionary history of arthropods. The study was published in Nature on Nov. 4.

The fossil species, Kylinxia, was collected from the Chengjiang fauna in southwest China’s Yunnan Province. The fauna documents the most complete early animal fossils in the Cambrian time.

Prof. Huang Diying, corresponding author for the study from NIGPAS, said, “Kylinxia is a very rare chimeric species. It combines morphological features from different animals, which is analogous to ‘kylin,’ a chimeric creature in traditional Chinese mythology.”

“Owing to very special taphonomic conditions, the Kylinxia fossils exhibit exquisite anatomical structures. For example, nervous tissue, eyes and digestive system—these are soft body parts we usually cannot see in conventional fossils,” said Prof. Zhao Fangchen, co-corresponding author of the study.

Kylinxia shows distinctive features of true arthropods, such as a hardened cuticle, a segmented trunk and jointed legs. However, it also integrates the morphological characteristics present in very ancestral forms, including the bizarre five eyes of Opabinia, known as the Cambrian “weird wonder,” as well as the iconic raptorial appendages of Anomalocaris, the giant apex predator in the Cambrian ocean.

Among the Chengjiang fauna, Anomalocaris is a top predator that can reach two meters in body length, and has been regarded as an ancestral form of arthropod. But huge morphological differences exist between Anomalocaris and true arthropods. There is a great evolutionary gap between the two that can hardly be bridged. This gap has become a crucial “missing link” in the origin of arthropods.

The research team conducted detailed anatomical examinations of the fossils of Kylinxia. They demonstrated that the first appendages in Anomalocaris and true arthropods were homologous. The phylogenetic analyses suggested that there was affinity between the front appendages of Kylinxia, small predatory appendages in front of the mouth of Chelicerata (a group that includes spiders and scorpions) and the antennae of Mandibulata (a subdivision of arthropods including insects such as ants and bees).

“Our results indicate that the evolutionary placement of Kylinxia is right between Anomalocaris and the true arthropods. Therefore, our finding reached the evolutionary root of the true arthropods,” said Prof. Zhu Maoyan, a co-author of the study.

“Kylinxia represents a crucial transitional fossil predicted by Darwin’s evolutionary theory. It bridges the evolutionary gap from Anomalocaris to true arthropods and forms a key “missing link” in the origin of arthropods, contributing strong fossil evidence for the evolutionary theory of life,” said Dr. Zeng Han, first author of the study.

Reference:
An early Cambrian euarthropod with radiodont-like raptorial appendages, Nature (2020). DOI: 10.1038/s41586-020-2883-7

Note: The above post is reprinted from materials provided by Chinese Academy of Sciences.

Pterodactyls and other related winged reptiles that lived alongside the dinosaurs steadily improved their ability to fly to become the deadly masters of the sky over the course of millions of years.

A new study published in the journal Nature has shown that pterosaurs — a group of creatures that became Earth’s first flying vertebrates — evolved to improve their flight performance over their 150 million-year existence, before they went extinct at the same time as the dinosaurs 66 million years ago.

Scientists from the Universities of Reading, Lincoln and Bristol carried out the most detailed study yet into how animals evolve to become better suited to their environments over time. They combined fossil records with a new model of flight based on today’s living birds to measure their flight efficiency and fill in the gaps in our knowledge of their evolutionary story.

This allowed the scientists to track the gradual evolution of pterosaurs and demonstrate that they became twice as good at flying over the course of their history. It also showed that their evolution was caused by consistent small improvements over a long period, rather than sudden evolutionary bursts as had been previously suggested.

Professor Chris Venditti, an evolutionary biologist at the University of Reading and lead author of the study, funded by the Leverhulme Trust, said: “Pterosaurs were a diverse group of winged lizards, with some the size of sparrows and others with the wingspan of a light aircraft. Fans of the movie Jurassic World will have seen a dramatisation of just how huge and lethal these creatures would have been. Their diet consisted mostly of other animals, from insects to smaller dinosaurs.

“Despite their eventual prowess in the air being well-known, the question of whether pterosaurs got better at flying and whether this gave them an advantage over their ancestors has puzzled scientists for decades. There are many examples of how natural selection works on relatively short time scales, but until now it has been very difficult to demonstrate whether plants or animals adapt to become more efficient over a long period.

“Our new method has allowed us to study long-term evolution in a completely new way, and answer this question at last by comparing the creatures at different stages of their evolutionary sequence over many millions of years.”

Pterosaurs evolved from land-based animals and first emerged as flyers in the Early Triassic period, around 245 million years ago. The first fossils are from 25 million years later.

The scientists monitored changes to pterosaur flight efficiency by using fossils to measure their wingspan and body size at different stages. Their new model based on living birds was applied to the data for 75 pterosaur species, which showed that pterosaurs gradually got better at flying over millions of years.

The models showed that pterosaurs adapted their body shape and size to use 50% less energy when flying over their 150 million-year history. They showed that the creatures increased in mass by 10 times, some to eventually weigh more than 300kg.

The new method also revealed that one group of pterosaurs — azhdarchoids — was an exception to the rule. Scientists have disagreed over how well these animals flew, but the new study showed that they did not get any better throughout their existence.

The enlarged size of azhdarchoids appeared to provide their survival advantage instead, with one animal — Quetzlcoatlus — growing to the height of a giraffe.

Dr Joanna Baker, evolutionary biologist and co-author at the University of Reading said: “This is unique evidence that although these animals were competent fliers, they probably spent much of their time on the ground. Highly efficient flight probably didn’t offer them much of an advantage, and our finding that they had smaller wings for their body size is in line with fossil evidence for their reduced reliance on flight.”

Professor Stuart Humphries, biophysicist and author from the University of Lincoln said: “One of the few things that haven’t changed over the last 300 million years are the laws of physics, so it has been great to use those laws to understand the evolution of flight in these amazing animals.”

Professor Mike Benton at the University of Bristol said, “Until recently, paleontologists could describe the anatomy of creatures based on their fossils and work out their functions. It’s really exciting now to be able to calculate the operational efficiency of extinct animals, and then to compare them through their evolution to see how efficiency has changed. We don’t just have to look at the fossils with amazement, but can really get to grips with what they tell us.”

Reference:
Chris Venditti, Joanna Baker, Michael J. Benton, Andrew Meade, Stuart Humphries. 150 million years of sustained increase in pterosaur flight efficiency. Nature, 2020; DOI: 10.1038/s41586-020-2858-8

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

About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. A short and flat tail, used for balance, helps identify it as a new species, according to research published in the Journal of Vertebrate Paleontology.

Paleontologists at the Chinese Academy of Scientists and Canadian Museum of Nature have analysed two skeletons from a thin layer of limestone in two quarries in southwest China. They identified the skeletons as nothosaurs, Triassic marine reptiles with a small head, fangs, flipper-like limbs, a long neck, and normally an even longer tail, probably used for propulsion. However, in the new species, the tail is short and flat.

“Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we’ve identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey,” says Dr Qing-Hua Shang from the Chinese Academy of Sciences, in Beijing.

The scientists have named the new species Brevicaudosaurus jiyangshanensis, from the Latin ‘brevi’ for ‘short,’ ‘caudo’ for ‘tail,’ and the Greek ‘sauros’ for ‘lizard.’ The most complete skeleton of the two was found in Jiyangshan quarry, giving the specimen its species name. It’s just under 60cm long.

The skeleton gives further clues to its lifestyle. The forelimbs are more strongly developed than the hind limbs, suggesting they played a role in helping the reptile to swim. However, the bones in the front feet are short compared to other species, limiting the power with which it could pull through the water. Most of its bones, including the vertebrae and ribs, are thick and dense, further contributing to the stocky, stout appearance of the reptile, and limiting its ability to swim quickly but increasing stability underwater.

However, thick, high-mass bones act as ballast. What the reptile lost in speed, it gained in stability. Dense bones, known as pachyostosis, may have made it neutrally buoyant in shallow water. Together with the flat tail, this would have helped the predator to float motionless underwater, requiring little energy to stay horizontal. Neutral buoyancy should also have enabled it to walk on the seabed searching for slow-moving prey.

Highly dense ribs may also suggest the reptile had large lungs. As suggested by the lack of firm support of the body weight, nothosaurs were oceanic nut they needed to come to the water surface for oxygen. They have nostrils on the snout through which they breathed. Large lungs would have increased the time the species could spend under water.

The new species features a bar-shaped bone in the middle ear called the stapes, used for sound transmission. The stapes was generally lost in other nothosaurs or marine reptiles during preservation. Scientists had predicted that if a stapes was found in a nothosaur, it would be thin and slender like in other species of this branch of the reptilian family tree. However, in B. jiyangshanensis it is thick and elongate, suggesting it had good hearing underwater.

“Perhaps this small, slow-swimming marine reptile had to be vigilante for large predators as it floated in the shallows, as well as being a predator itself,” says co-author Dr. Xiao-Chun Wu from the Canadian Museum of Nature.

Reference:
Qing-Hua Shang, Xiao-Chun Wu, Chun Li. A New Ladinian Nothosauroid (Sauropterygia) from Fuyuan, Yunnan Province, China. Journal of Vertebrate Paleontology, 2020; e1789651 DOI: 10.1080/02724634.2020.1789651

Note: The above post is reprinted from materials provided by Taylor & Francis Group.

A new study of coprolites, fossil poop, shows the detail of food webs in the ancient shallow seas around Bristol in south-west England. One hungry fish ate part of the head of another fish before snipping off the tail of a passing reptile.

Marie Cueille, a visiting student at the University of Bristol’s School of Earth Sciences, was working on a collection of hundreds of fish poops from the Rhaetian bone bed near Chipping Sodbury in South Gloucestershire, dated at 205 million years ago.

She applied new scanning technology to look inside these coprolites and found an amazing array of food remains.

Marie said: “The ancient fishes and sharks of the Rhaetian seas were nearly all carnivores. Their coprolites contain scales, teeth, and bones, and these tell us who was eating whom. In fact, all the fish seem to have been snapping at each other, although the general rule of the sea probably applied: if it’s smaller than you, eat it.”

The CT scans of one tiny coprolite, measuring only a centimeter or so in length, contained only three bones, one a highly tuberculated skull bone of another fish, and two vertebrae from the tail of a small marine reptile called Pachystropheus.

Dr. Chris Duffin, who collaborated on the project added: “This shark probably snapped at another fish or scavenged some flesh from the head region of a dead fish. But it didn’t just strip off the flesh but swallowed great chunks of bone at the same time. Then it snapped at a Pachystropheus swimming by and had a chunk of its tail.”

Professor Mike Benton, who co-supervised the study, said: “What amazed us was that the bones and scales inside the coprolites were almost completely undamaged. Today, most predators that swallow their prey whole, such as sharks, crocodiles or killer whales, have powerful stomach acids that dissolve the bone away. These ancient fishes must have had a painful time passing their feces which were absolutely bristling with relatively large chunks of bone.”

The researchers also identified for the first time some coprolites of crabs and lobsters, so this completes the food web. The marine reptiles and sharks were feeding on smaller fishes, which in turn fed on even smaller fishes and lobsters. Some also had crushing teeth adapted to feeding on oysters and other molluscs.

The study has a classical resonance as well, because Rhaetian coprolites from bonebeds near Bristol were some of those studied by William Buckland (1784–1856) in the 1820s when he invented the name coprolite. Buckland was professor of geology at Oxford University, but also Dean of Christ Church, and known for his unusual eating habits. Possibly his interest in eating exotic animals (he would serve his guests roasted dormice or potted panther but declared that moles and house flies were inedible) gave him an interest in animal diets.

Buckland pioneered the use of coprolites to reconstruct ancient food webs. He also collected specimens from the Jurassic around Lyme Regis, and many were supplied by famous fossil collector Mary Anning (1799–1847). Buckland even had these larger coprolites cut across and set into the top of a table, which was highly polished and doubtless formed a conversation opener during lunch and tea parties in the Dean’s lodgings.

The new work also sheds light on the Mesozoic Marine Revolution, the time when marine ecosystems modernized. The coprolites from Bristol show a complex, modern-style ecosystem with lobsters, bony fishes, sharks and marine reptiles at the top of the food web. Reconstructing the timing of the event is of current interest, and the new work suggests the process began earlier than had been thought.

Reference:
Marie Cueille et al. Fish and crab coprolites from the latest Triassic of the UK: From Buckland to the Mesozoic Marine Revolution, Proceedings of the Geologists’ Association (2020). DOI: 10.1016/j.pgeola.2020.07.011

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