Fossil finds give clues about flying reptiles in the Sahara 100 million years ago

Three new species of toothed pterosaurs — flying reptiles of the Cretaceous period, some 100 million years ago — have been identified in Africa by an international team of scientists led by Baylor University.

The pterosaurs, which soared above a world dominated by predators, formed part of an ancient river ecosystem in Africa that teemed with life including fish, crocodiles, turtles and several predatory dinosaurs.

“Pterosaur remains are very rare, with most known from Europe, South America and Asia. These new finds are very exciting and provide a window into the world of pterosaurs in Cretaceous Africa,” said lead author Megan L. Jacobs, a doctoral candidate in geosciences at Baylor University.

The study, published in the journal Cretaceous Research, is helping to uncover the poorly known evolutionary history of Africa during the time of the dinosaurs. The research finds that African pterosaurs were quite similar to those found on other continents. Their world included crocodile-like hunters and carnivorous dinosaurs, with few herbivores. Many predators, including the toothed pterosaurs, preyed on a superabundance of fish.

“For such large animals, they would have weighed very little,” Jacobs said. “Their wingspans were around 10 to 13 feet, with their bones almost paper-thin and full of air, very similar to birds. This allowed these awesome creatures to reach incredible sizes and still be able to take off and soar the skies.”

Pterosaurs snatched up their prey while on the wing, using a set of large spike-like teeth to grab. Large pterosaurs such as these would have been able to forage over hundreds of miles, with fossil evidence showing they flew between South America and Africa, similar to present-day birds such as condors and albatrosses, researchers said.

The specimens — identified by researchers from chunks of jaws with teeth — were obtained from fossil miners in a small village called Beggaa, just outside Erfoud in southeast Morocco. These villagers daily climb halfway up the side of a large escarpment, known as the Kem Kem beds, to a layer of a coarse sand, the most fossiliferous bed.

“They excavate everything they find, from teeth to bones to almost complete skeletons,” Jacobs said. “They then sell their finds to dealers and scientists who conduct fieldwork, ensuring the villagers make enough money to survive while we get new fossils to describe. These pterosaur fragments are unique and can be identified easily — if you know what to look for.”

One of the species, Anhanguera, previously was only known to be from Brazil. Another, Ornithocheirus, had until now only been found in England and Middle Asia.

This year’s find brings to five the total of toothed pterosaurs whose remains have been found in the Kem Kem beds, with the first described in the 1990s and the second one last year, Jacobs said. The specimens will be part of an acquisition in a museum in Morocco.


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Journal Reference:

  1. Megan L. Jacobs, David M. Martill, David M. Unwin, Nizar Ibrahim, Samir Zouhri, Nicholas R. Longrich. New toothed pterosaurs (Pterosauria: Ornithocheiridae) from the middle Cretaceous Kem Kem beds of Morocco and implications for pterosaur palaeobiogeography and diversityCretaceous Research, 2020; 110: 104413 DOI: 10.1016/j.cretres.2020.104413

Ancestor of all animals identified in Australian fossils

A team led by UC Riverside geologists has discovered the first ancestor on the family tree that contains most familiar animals today, including humans.

The tiny, wormlike creature, named Ikaria wariootia, is the earliest bilaterian, or organism with a front and back, two symmetrical sides, and openings at either end connected by a gut. The paper is published today in Proceedings of the National Academy of Sciences.

The earliest multicellular organisms, such as sponges and algal mats, had variable shapes. Collectively known as the Ediacaran Biota, this group contains the oldest fossils of complex, multicellular organisms. However, most of these are not directly related to animals around today, including lily pad-shaped creatures known as Dickinsonia that lack basic features of most animals, such as a mouth or gut.

The development of bilateral symmetry was a critical step in the evolution of animal life, giving organisms the ability to move purposefully and a common, yet successful way to organize their bodies. A multitude of animals, from worms to insects to dinosaurs to humans, are organized around this same basic bilaterian body plan.

Evolutionary biologists studying the genetics of modern animals predicted the oldest ancestor of all bilaterians would have been simple and small, with rudimentary sensory organs. Preserving and identifying the fossilized remains of such an animal was thought to be difficult, if not impossible.

For 15 years, scientists agreed that fossilized burrows found in 555 million-year-old Ediacaran Period deposits in Nilpena, South Australia, were made by bilaterians. But there was no sign of the creature that made the burrows, leaving scientists with nothing but speculation.

Scott Evans, a recent doctoral graduate from UC Riverside; and Mary Droser, a professor of geology, noticed miniscule, oval impressions near some of these burrows. With funding from a NASA exobiology grant, they used a three-dimensional laser scanner that revealed the regular, consistent shape of a cylindrical body with a distinct head and tail and faintly grooved musculature. The animal ranged between 2-7 millimeters long and about 1-2.5 millimeters wide, with the largest the size and shape of a grain of rice — just the right size to have made the burrows.

“We thought these animals should have existed during this interval, but always understood they would be difficult to recognize,” Evans said. “Once we had the 3D scans, we knew that we had made an important discovery.”

The researchers, who include Ian Hughes of UC San Diego and James Gehling of the South Australia Museum, describe Ikaria wariootia, named to acknowledge the original custodians of the land. The genus name comes from Ikara, which means “meeting place” in the Adnyamathanha language. It’s the Adnyamathanha name for a grouping of mountains known in English as Wilpena Pound. The species name comes from Warioota Creek, which runs from the Flinders Ranges to Nilpena Station.

“Burrows of Ikaria occur lower than anything else. It’s the oldest fossil we get with this type of complexity,” Droser said. “Dickinsonia and other big things were probably evolutionary dead ends. We knew that we also had lots of little things and thought these might have been the early bilaterians that we were looking for.”

In spite of its relatively simple shape, Ikaria was complex compared to other fossils from this period. It burrowed in thin layers of well-oxygenated sand on the ocean floor in search of organic matter, indicating rudimentary sensory abilities. The depth and curvature of Ikaria represent clearly distinct front and rear ends, supporting the directed movement found in the burrows.

The burrows also preserve crosswise, “V”-shaped ridges, suggesting Ikaria moved by contracting muscles across its body like a worm, known as peristaltic locomotion. Evidence of sediment displacement in the burrows and signs the organism fed on buried organic matter reveal Ikaria probably had a mouth, anus, and gut.

“This is what evolutionary biologists predicted,” Droser said. “It’s really exciting that what we have found lines up so neatly with their prediction.”


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Beetles changed their diet during the Cretaceous period International team decodes 99 million-year-old amber fossils

Like a snapshot, amber preserves bygone worlds. An international team of paleontologists from the University of Bonn has now described four new beetle species in fossilized tree resin from Myanmar, which belong to the Kateretidae family. They still exist today, with only a few species. As well as the about 99 million years old insects, the amber also includes pollen. It seems that the beetles helped the flowering plants to victory, because they contributed to their propagation. In turn, the beetles benefited from the new food source. The results have now been published in the journal “iScience.”

The researchers have described the new beetle species using specimens in four amber pieces from Myanmar (previously known as Burma). The pieces are estimated to be 99 million years old and date from the Cretaceous period, when dinosaurs were a rich and diverse group. Two of the pieces are in the Museum of Natural Sciences of Barcelona (Spain), while the other two specimens are kept in the Institute of Geology and Palaeontology in Nanjing (China).

“Although Myanmar surprises us time and again with finds of great scientific importance, amber pieces containing numerous organisms are not often found there,” says project leader Dr. David Peris, who comes from Spain and is a postdoc at the Institute for Geosciences at the University of Bonn with an Alexander von Humboldt Foundation’s fellowship. He carried out the project with scientists from the USA, Spain, Germany, China and the Czech Republic.

Three of the examined amber pieces contained numerous beetles, while the fourth piece contained only one specimen of this family. Many pollen grains of different groups of seed plants, some of them long extinct, have been preserved with the beetles in the tree resin. Peris: “This close association suggests that the grains were distributed in the viscous lump of resin by the movement of the beetles.”

The beetle family still exists today

The Kateretidae are a small family of beetles with less than 100 described modern species that today live in South America and other temperate and subtropical regions. The species of this family feed on pollen and flower parts. Due to their dietary habits, they are nowadays regarded as pollinators of flowering plants (angiosperms). But in the middle Cretaceous period their rapid development had just begun. Previously, the Earth was colonized by gymnosperms, literally meaning “naked seeds,” which also includes our conifers. “The most important aspect of this study is that the pollen grains in three of the amber pieces do not belong to flowering plants,” says Peris. The pollen grains on the beetle of the fourth piece of amber, however, come from a water lily, a group of very primitive angiosperms that emerged at an early stage.

Living together for mutual benefit

There are other pollinating insects in amber, but almost all of them concern gymnosperms. When flowering plants (angiosperms) began their early development, they represented a new resource that was used by the Kateretidae. The beetles adapted quickly and formed a mutually beneficial symbiosis: The flowering plants served the beetles as a food source and these animals contributed to the propagation of the new angiosperms by pollination.

In earlier studies it was speculated that the beetles might belong to the insect groups that pollinated the earliest flowers. Some of these animals had developed the ability to pollinate gymnosperms well before the appearance of angiosperms. “Our study supports this hypothesis of significant host plant relocation, as there are no Kateretidae associated with gymnosperms today,” says Peris. Adapting to the new resource has proven to be an evolutionary advantage.


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‘Wonderchicken’ fossil from the age of dinosaurs reveals origin of modern birds

The oldest fossil of a modern bird yet found, dating from the age of dinosaurs, has been identified by an international team of palaeontologists.

The spectacular fossil, affectionately nicknamed the ‘Wonderchicken’, includes a nearly complete skull, hidden inside nondescript pieces of rock, and dates from less than one million years before the asteroid impact which eliminated all large dinosaurs.

Writing in the journal Nature, the team, led by the University of Cambridge, believe the new fossil helps clarify why birds survived the mass extinction event at the end of the Cretaceous period, while the giant dinosaurs did not.

Detailed analysis of the skull shows that it combines many features common to modern chicken- and duck-like birds, suggesting that the ‘Wonderchicken’ is close to the last common ancestor of modern chickens and ducks. The fossil was found in a limestone quarry near the Belgian-Dutch border, making it the first modern bird from the age of dinosaurs found in the northern hemisphere.

The fossil doesn’t look like much on first glance, with only a few small leg bone fragments poking out from a piece of rock the size of a deck of cards. Even those small bones attracted the researchers’ interest, since bird fossils from this point in Earth’s history are so rare.

Using high-resolution X-ray CT scans, the researchers peered through the rock to see what was lying beneath the surface. What they saw, just one millimetre beneath the rock, was the find of a lifetime: a nearly complete 66.7-million-year-old bird skull.

“The moment I first saw what was beneath the rock was the most exciting moment of my scientific career,” said Dr Daniel Field from Cambridge’s Department of Earth Sciences, who led the research. “This is one of the best-preserved fossil bird skulls of any age, from anywhere in the world. We almost had to pinch ourselves when we saw it, knowing that it was from such an important time in Earth’s history.

“The ability to CT scan fossils, like we can at the Cambridge Biotomography Centre, has completely transformed how we study palaeontology in the 21st century.”

“Finding the skull blew my mind,” said co-author Juan Benito, also from Cambridge, who was CT scanning the fossils with Field when the skull was discovered. “Without these cutting-edge scans, we never would have known that we were holding the oldest modern bird skull in the world.”

The skull, despite its age, is clearly recognisable as a modern bird. It combines many features common to the group that includes living chickens and ducks — a group called Galloanserae. Field describes the skull as a kind of ‘mash-up’ of a chicken and a duck.

“The origins of living bird diversity are shrouded in mystery — other than knowing that modern birds arose at some point towards the end of the age of dinosaurs, we have very little fossil evidence of them until after the asteroid hit,” said co-author Albert Chen, a PhD student based at Cambridge. “This fossil provides our earliest direct glimpse of what modern birds were like during the initial stages of their evolutionary history.”

While the fossil is colloquially known as the Wonderchicken, the researchers have given it the slightly more elegant name of Asteriornis, in reference to Asteria, the Greek Titan goddess of falling stars.

“We thought it was an appropriate name for a creature that lived just before the end-Cretaceous asteroid impact,” said co-author Dr Daniel Ksepka from the Bruce Museum in Greenwich, Connecticut. “In Greek mythology, Asteria transforms herself into a quail, and we believe Asteriornis was close to the common ancestor that today includes quails, as well as chickens and ducks.”

The fact that Asteriornis was found in Europe is another thing which makes it so extraordinary. “The late Cretaceous fossil record of birds from Europe is extremely sparse,” said co-author Dr John Jagt from the Natuurhistorische Museum Maastricht in the Netherlands. “The discovery of Asteriornis provides some of the first evidence that Europe was a key area in the early evolutionary history of modern birds.”

“This fossil tells us that early on, at least some modern birds were fairly small-bodied, ground-dwelling birds that lived near the seashore,” said Field. “Asteriornis now gives us a search image for future fossil discoveries — hopefully it ushers in a new era of fossil finds that help clarify how, when and where modern birds first evolved.”

The announcement of the Wonderchicken find coincides with a new exhibit at Cambridge’s Sedgwick Museum of Earth Sciences, where visitors can learn more about Asteriornis and see the fossil up close. “Dawn of the Wonderchicken” runs from 19 March to 15 June. Admission is free.

Dr Daniel Field is funded by a UKRI Future Leaders Fellowship. He is a University Lecturer in the Department of Earth Sciences at the University of Cambridge, and a Fellow of Christ’s College Cambridge.


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Dinosaur stomping ground in Scotland reveals thriving middle Jurassic ecosystem

During the Middle Jurassic Period, the Isle of Skye in Scotland was home to a thriving community of dinosaurs that stomped across the ancient coastline, according to a study published March 11, 2020 in the open-access journal PLOS ONE by Paige dePolo and Stephen Brusatte of the University of Edinburgh, Scotland and colleagues.

The Middle Jurassic Period is a time of major evolutionary diversification in many dinosaur groups, but dinosaur fossils from this time period are generally rare. The Isle of Skye in Scotland is an exception, yielding body and trace fossils of diverse Middle Jurassic ecosystems, serving as a valuable location for paleontological science as well as tourism.

In this paper, dePolo and colleagues describe two recently discovered fossil sites preserving around 50 dinosaur footprints on ancient coastal mudflats. These include the first record on the Isle of Skye of a track type called Deltapodus, most likely created by a stegosaurian (plate-backed) dinosaur. These are the oldest Deltapodus tracks known, and the first strong evidence that stegosaurian dinosaurs were part of the island’s Middle Jurassic fauna. Additionally, three-toed footprints represent multiple sizes of early carnivorous theropods and a series of other large tracks are tentatively identified as some of the oldest evidence of large-bodied herbivorous ornithopod dinosaurs.

All tracks considered, these two sites expand the known diversity of what was apparently a thriving ecosystem of Middle Jurassic dinosaurs in Scotland, including at least one type of dinosaur (stegosaurs) not previously known from the region. These findings reflect the importance of footprints as a source of information supplemental to body fossils. Furthermore, the authors stress the importance of revisiting previously explored sites; these new sites were found in an area that has long been popular for fossil prospecting, but the trackways were only recently revealed by storm activity.

Lead author dePolo says: “These new tracksites help us get a better sense of the variety of dinosaurs that lived near the coast of Skye during the Middle Jurassic than what we can glean from the island’s body fossil record. In particular, Deltapodus tracks give good evidence that stegosaurs lived on Skye at this time.”

Author Brusatte adds: “These new tracksites give us a much clearer picture of the dinosaurs that lived in Scotland 170 million years ago. We knew there were giant long-necked sauropods and jeep-sized carnivores, but we can now add plate-backed stegosaurs to that roster, and maybe even primitive cousins of the duck-billed dinosaurs too. These discoveries are making Skye one of the best places in the world for understanding dinosaur evolution in the Middle Jurassic.”


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Journal Reference:

  1. dePolo PE, Brusatte SL, Challands TJ, Foffa D, Wilkinson M, Clark NDL, et al. Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, ScotlandPLOS ONE, 2020 DOI: 10.1371/journal.pone.0229640

Mystery surrounding dinosaur footprints on a cave ceiling in Central Queensland solved

The mystery surrounding dinosaur footprints on a cave ceiling in Central Queensland has been solved, in article published in Historical Biology, after more than a half a century.

University of Queensland palaeontologist Dr Anthony Romilio discovered pieces to a decades-old puzzle in an unusual place — a cupboard under the stairs of a suburban Sydney home.

“The town of Mount Morgan near Rockhampton has hundreds of fossil footprints and has the highest dinosaur track diversity for the entire eastern half of Australia,” Dr Romilio said.

“Earlier examinations of the ceiling footprints suggested some very curious dinosaur behaviour; that a carnivorous theropod walked on all four legs.

“You don’t assume T. rex used its arms to walk, and we didn’t expect one of its earlier predatory relatives of 200 million years ago did either.”

Researchers wanted to determine if this dinosaur did move using its feet and arms, but found accessing research material was difficult.

“For a decade the Mount Morgan track site has been closed, and the published 1950s photographs don’t show all the five tracks,” Dr Romilio said.

However Dr Romilio had a chance meeting with local dentist Dr Roslyn Dick, whose father found many dinosaur fossils over the years.

“I’m sure Anthony didn’t believe me until I mentioned my father’s name — Ross Staines,” Ms Dick said.

“Our father was a geologist and reported on the Mount Morgan caves containing the dinosaur tracks in 1954.

“Besides his published account, he had high-resolution photographs and detailed notebooks, and my sisters and I had kept it all.

“We even have his dinosaur footprint plaster cast stored under my sister’s Harry Potter cupboard in Sydney.”

Dr Romilio said the wealth and condition of ‘dinosaur information’ archived by Ms Dick and her sisters Heather Skinner and Janice Millar was amazing.

“I’ve digitised the analogue photos and made a virtual 3D model of the dinosaur footprint, and left the material back to the family’s care,” he said.

“In combination with our current understanding of dinosaurs, it told a pretty clear-cut story.”

The team firstly concluded that all five tracks were foot impressions — that none were dinosaur handprints.

Also the splayed toes and moderately long middle digit of the footprints resembled two-legged herbivorous dinosaur tracks, differing from prints made by theropods.

“Rather than one dinosaur walking on four legs, it seems as though we got two dinosaurs for the price of one — both plant-eaters that walked bipedally along the shore of an ancient lake,” Dr Romilio said.

“The tracks lining the cave-ceiling were not made by dinosaurs hanging up-side-down, instead the dinosaurs walked on the lake sediment and these imprints were covered in sand.

“In the Mount Morgan caves, the softer lake sediment eroded away and left the harder sandstone in-fills.”


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Journal Reference:

  1. Anthony Romilio, Roslyn Dick, Heather Skinner, Janice Millar. Archival data provides insights into the ambiguous track-maker gait from the Lower Jurassic (Sinemurian) Razorback beds, Queensland, Australia: evidence of theropod quadrupedalism? Historical Biology, 2020; 1 DOI: 10.1080/08912963.2020.1720014

Rare lizard fossil preserved in amber

The tiny forefoot of a lizard of the genus Anolis was trapped in amber about 15 to 20 million years ago. Every detail of this rare fossil is visible under the microscope. But the seemingly very good condition is deceptive: The bone is largely decomposed and chemically transformed, very little of the original structure remains. The results, which are now presented in the journal PLOS ONE, provide important clues as to what exactly happens during fossilization.

How do fossils stay preserved for millions of years? Rapid embedding is an important prerequisite for protecting the organisms from access by scavengers, for example. Decomposition by microorganisms can for instance be prevented by extreme aridity. In addition, the original substance is gradually replaced by minerals. The pressure from the sediment on top of the fossil ensures that the fossil is solidified. “That’s the theory,” says Jonas Barthel, a doctoral student at the Institute for Geosciences at the University of Bonn. “How exactly fossilization proceeds is currently the subject of intensive scientific investigation.”

Amber is considered an excellent preservative. Small animals can be enclosed in a drop of tree resin that hardens over time. A team of geoscientists from the University of Bonn has now examined an unusual find from the Dominican Republic: The tiny forefoot of a lizard of the genus Anolis is enclosed in a piece of amber only about two cubic centimeters in size. Anolis species still exist today.

Vertebrate inclusions in amber are very rare

The Stuttgart State Museum of Natural History has entrusted the exhibit to the paleontologists of the University of Bonn for examination. “Vertebrate inclusions in amber are very rare, the majority are insect fossils,” says Barthel. The scientists used the opportunity to investigate the fossilization of the seemingly very well preserved vertebrate fragment. Since 2018 there is a joint research project of the University of Bonn with the German Research Foundation, which contributes to the understanding of fossilization using experimental and analytical approaches. The present study was also conducted within the framework of this project.

The researchers had thin sections prepared for microscopy at the Institute for Evolutionary Biology at the University of Bonn. The claws and toes are very clearly visible in the honey-brown amber mass, almost as if the tree resin had only recently dripped onto them — yet the tiny foot is about 15 to 20 million years old.

Scans in the micro-computer tomograph of the Institute for Geosciences revealed that the forefoot was broken in two places. One of the fractures is surrounded by a slight swelling. “This is an indication that the lizard had perhaps been injured by a predator,” says Barthel. The other fracture happened after the fossil was embedded — exactly at the place where a small crack runs through the amber.

Amber did not protect from environmental influences

The analysis of a thin section of bone tissue using Raman spectroscopy revealed the state of the bone tissue. The mineral hydroxyapatite in the bone had been transformed into fluoroapatite by the penetration of fluorine. Barthel: “This is surprising, because we assumed that the surrounding amber largely protects the fossil from environmental influences.” However, the small crack may have encouraged chemical transformation by allowing mineral-rich solutions to find their way in. In addition, Raman spectroscopy shows that collagen, the bone’s elastic component, had largely degraded. Despite the seemingly very good state of preservation, there was actually very little left of the original tissue structure.

“We have to expect that at least in amber from the Dominican Republic, macromolecules are no longer detectable,” says the supervisor of the study, Prof. Dr. Jes Rust from the Institute for Geosciences. It was not possible to detect more complex molecules such as proteins, but final analyses are still pending. The degradation processes in this amber deposit are therefore very advanced, and there is very little left of the original substance.

Acids in tree resin attack bone

Amber is normally considered an ideal preservative: Due to the tree resin, we have important insights into the insect world of millions of years. But in the lizard’s bone tissue, the resin might even have accelerated the degradation processes: Acids in the tree secretion have probably attacked the apatite in the bone — similar to tooth decay.


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New thalattosaur species discovered in Southeast Alaska

Scientists at the University of Alaska Fairbanks have identified a new species of thalattosaur, a marine reptile that lived more than 200 million years ago.

The new species, Gunakadeit joseeae, is the most complete thalattosaur ever found in North America and has given paleontologists new insights about the thalattosaurs’ family tree, according to a paper published today in the journal Scientific Reports. Scientists found the fossil in Southeast Alaska in 2011.

Thalattosaurs were marine reptiles that lived more than 200 million years ago, during the mid to late Triassic Period, when their distant relatives — dinosaurs — were first emerging. They grew to lengths of up to 3-4 meters and lived in equatorial oceans worldwide until they died out near the end of the Triassic.

“When you find a new species, one of the things you want to do is tell people where you think it fits in the family tree,” said Patrick Druckenmiller, the paper’s lead author and director and earth sciences curator at the University of Alaska Museum of the North. “We decided to start from scratch on the family tree.”

Prior to the discovery of Gunakadeit joseeae, it had been two decades since scientists had thoroughly updated thalattosaur interrelationships, Druckenmiller said. The process of re-examining a prehistoric animal’s family tree involves analyzing dozens and dozens of detailed anatomical features from fossil specimens worldwide, then using computers to analyze the information to see how the different species could be related.

Druckenmiller said he and collaborator Neil Kelley from Vanderbilt University were surprised when they identified where Gunakadeit joseeae landed.

“It was so specialized and weird, we thought it might be out at the furthest branches of the tree,” he said. Instead it’s a relatively primitive type of thalattosaur that survived late into the existence of the group.

“Thalattosaurs were among the first groups of land-dwelling reptiles to readapt to life in the ocean,” Kelley said. “They thrived for tens of millions of years, but their fossils are relatively rare so this new specimen helps fill an important gap in the story of their evolution and eventual extinction.”

That the fossil was found at all is a remarkable. It was located in rocks in the intertidal zone. The site is normally underwater all but a few days a year. In Southeast Alaska, when extreme low tides hit, people head to the beaches to explore. That’s exactly what Jim Baichtal, a geologist with the U.S. Forest Service’s Tongass National Forest, was doing on May 18, 2011, when low tides of -3.7 feet were predicted.

He and a few colleagues, including Gene Primaky, the office’s information technology professional, headed out to the Keku Islands near the village of Kake to look for fossils. Primaky saw something odd on a rocky outcrop and called over Baichtal, “Hey Jim! What is this?” Baichtal immediately recognized it as a fossilized intact skeleton. He snapped a photo with his phone and sent it to Druckenmiller.

A month later, the tides were forecasted to be almost that low, -3.1 feet, for two days. It was the last chance they would have to remove the fossil during daylight hours for nearly a year, so they had to move fast. The team had just four hours each day to work before the tide came in and submerged the fossil.

“We rock-sawed like crazy and managed to pull it out, but just barely,” Druckenmiller said. “The water was lapping at the edge of the site.”

Once the sample was back at the UA Museum of the North, a fossil preparation specialist worked in two-week stints over the course of several years to get the fossil cleaned up and ready for study.

When they saw the fossil’s skull, they could tell right away that it was something new because of its extremely pointed snout, which was likely an adaptation for the shallow marine environment where it lived.

“It was probably poking its pointy schnoz into cracks and crevices in coral reefs and feeding on soft-bodied critters,” Druckenmiller said. Its specialization may have been what ultimately led to its extinction. “We think these animals were highly specialized to feed in the shallow water environments, but when the sea levels dropped and food sources changed, they had nowhere to go.”

Once the fossil was identified as a new species, it needed a name. To honor the local culture and history, elders in Kake and representatives of Sealaska Corp. agreed the Tlingit name “Gunakadeit” would be appropriate. Gunakadeit is a sea monster of Tlingit legend that brings good fortune to those who see it. The second part of the new animal’s name, joseeae, recognizes Primaky’s mother, Joseé Michelle DeWaelheyns.


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New species of Allosaurus discovered in Utah

A remarkable new species of meat-eating dinosaur has been unveiled at the Natural History Museum of Utah. Paleontologists unearthed the first specimen in early 1990s in Dinosaur National Monument in northeastern Utah. The huge carnivore inhabited the flood plains of western North America during the Late Jurassic Period, between 157-152 million years ago, making it the geologically oldest species of Allosaurus, predating the more well-known state fossil of Utah, Allosaurus fragilis. The newly named dinosaur Allosaurus jimmadseni, was announced today in the open-access scientific journal PeerJ.

The species belongs to the allosauroids, a group of small to large-bodied, two-legged carnivorous dinosaurs that lived during the Jurassic and Cretaceous periods. Allosaurus jimmadseni, possesses several unique features, among them a short narrow skull with low facial crests extending from the horns in front of the eyes forward to the nose and a relatively narrow back of the skull with a flat surface to the bottom of the skull under the eyes. The skull was weaker with less of an overlapping field of vision than its younger cousin Allosaurus fragilisAllosaurus jimmadseni evolved at least 5 million years earlier than fragilis, and was the most common and the top predator in its ecosystem. It had relatively long legs and tail, and long arms with three sharp claws. The name Allosaurus translates as “different reptile,” and the second part, jimmadseni, honors Utah State Paleontologist James H. Madsen Jr.

Following an initial description by Othniel C. Marsh in 1877, Allosaurus quickly became the best known — indeed the quintessential — Jurassic theropod. The taxonomic composition of the genus has long been a debate over the past 130 years. Paleontologists argue that there are anywhere between one and 12 species of Allosaurus in the Morrison Formation of North America. This study recognizes only two species — A. fragilis and A. jimmadseni.

“Previously, paleontologists thought there was only one species of Allosaurus in Jurassic North America, but this study shows there were two species — the newly described Allosaurus jimmadseni evolved at least 5 million years earlier than its younger cousin, Allosaurus fragilis,” said co-lead author Mark Loewen, research associate at the Natural History Museum of Utah, and associate professor in the Department of Geology and Geophysics at the University of Utah led the study. “The skull of Allosaurus jimmadseni is more lightly built than its later relative Allosaurus fragilis, suggesting a different feeding behavior between the two.”

George Engelmann of the University of Nebraska, Omaha initially discovered the initial skeleton of the new species within Dinosaur National Monument in 1990. In 1996, several years after the headless skeleton was collected, the radioactive skull belonging to the skeleton using a radiation detector by Ramal Jones of the University of Utah. Both skeleton and skull were excavated by teams from Dinosaur National Monument.

“Big Al,” another specimen belonging to the new species, was discovered in Wyoming on United States Bureau of Land Management (BLM) land in 1991 and is housed in the collections of the Museum of The Rockies in Bozeman, Montana. Previously thought to belong to Allosaurus fragilis, “Big Al” was featured in the BBC’s 2001 “Walking with Dinosaurs: Ballad of Big Al” video. Over the last 30 years, crews from various museums have collected and prepared materials of this new species. Other specimens include “Big Al Two” at the Saurier Museum Aathal in Switzerland and Allosaurus material from the Dry Mesa Quarry of Colorado at Brigham Young University.

Early Morrison Formation dinosaurs were replaced by some of the most iconic dinosaurs of the Late Jurassic

Allosaurus jimmadseni lived on the semi-arid Morrison Formation floodplains of the interior of western North America. The older rocks of the Morrison Formation preserve a fauna of dinosaurs distinct from the iconic younger Morrison Formation faunas that include Allosaurus fragilis, Diplodocus and Stegosaurus. Paleontologists have recently determined that specimens of this new species of dinosaur lived in several places throughout the western interior of North America (Utah, Colorado and Wyoming).

Study summary

Dinosaurs were the dominant members of terrestrial ecosystems during the Mesozoic. However, the pattern of evolution and turnover of ecosystems during the middle Mesozoic remains poorly understood. The authors report the discovery of the earliest member of the group of large-bodied allosauroids in the Morrison Formation ecosystem that was replaced by Allosaurus fragilis and illustrate changes acquired in the genus over time. The study includes an in-depth description of every bone of the skull and comparisons with the cranial materials of other carnivorous dinosaurs. Finally, the study recognizes just two species of Allosaurus in North America with Allosaurus fragilis replacing its earlier relative Allosaurus jimmadseni.

Fact sheet: Major points of the paper

  • A remarkable new species of meat-eating dinosaur, Allosaurus jimmadseni, is described based on two spectacularly complete skeletons. The first specimen was unearthed in Dinosaur National Monument, in northeastern Utah.
  • Allosaurus jimmadseni is distinguished by a number of unique features, including low crests running from above the eyes to the snout and a relatively narrow back of the skull with a flat surface to the bottom of the upper skull under the eyes. The skull was weaker with less of an overlapping field of vision than its younger cousin Allosaurus fragilis.
  • At 155 million years old, Allosaurus jimmadseni is the geologically-oldest species of Allosaurus predating the more well-known State Fossil of Utah Allosaurus fragilis.
  • Allosaurus jimmadseni was the most common and the top predator in its ecosystem. It had relatively long legs and tail, and long arms with three sharp claws.

Study design

  • Comparison of the bones with all other known allosauroid dinosaurs indicate that the species possessed unique features of the upper jaw and cheeks (maxilla and jugal) and a decorative crest stretching from just in front of the eyes to the nose.
  • Many of the comparisons were made with the thousands of bones of Allosaurus fragilis collected from the famous Cleveland-Lloyd Dinosaur Quarry administered by the Bureau of Land Management that are housed in the collections of the Natural History Museum of Utah.
  • On the basis of these features, the scientific team named it a new genus and species of dinosaur, Allosaurus jimmadseni (translating to “Jim Madsen’s different reptile”).
  • Allosaurus jimmadseni is particularly notable for its slender, narrow skull with short sharp nasal crests compared to its close relative and successor Allosaurus fragilis.
  • The study was funded in part by the University of Utah, the National Park Service and the National Science Foundation.

New dinosaur name: Allosaurus jimmadseni

  • The first part of the name, Allosaurus, (a·luh·SAW·ruhs) can be translated from Greek as the “other,” “strange” or “different” and “lizard” or “reptile” literally to “different reptile.” The second part of the name jimmadseni (gym-MAD-sehn-eye) honors the late Utah State Paleontologist James Madsen Jr. who excavated and studied tens of thousands of Allosaurus bones from the famous Cleveland-Lloyd Dinosaur Quarry in central Utah and contributed greatly to the knowledge of Allosaurus.

Size

  • Allosaurus jimmadseni was approximately 26 to 29 feet (8-9 meters) long.
  • Allosaurus jimmadseni weighed around 4000 lbs. (1.8 metric tonnes).

Relationships

  • Allosaurus jimmadseni belongs to a group of carnivorous dinosaurs called “allosauroids,” the same group as the famous Allosaurus fragilis.
  • Other dinosaurs found in rocks containing Allosaurus jimmadseni include the carnivorous theropods Torvosaurus and Ceratosaurus; the long-necked sauropods Haplocanthosaurus and Supersaurus; and the plate-backed stegosaur Hesperosaurus.
  • Allosaurus jimmadseni is closely related to the State Fossil of Utah, Allosaurus fragilis.

Anatomy

  • Allosaurus jimmadseni was a two-legged carnivore, with long forelimbs and sharp, recurved claws that were likely used for grasping prey.
  • Like other allosauroid dinosaurs, Allosaurus jimmadseni had a large head full of 80 sharp teeth. It was also the most common carnivore in its ecosystem.

Age and geography

  • Allosaurus jimmadseni lived during the Kimmeridgian stage of the Late Jurassic period, which spanned from approximately 157 million to 152 million years ago.
  • Allosaurus jimmadseni lived in a semi-arid inland basin filled with floodplains, braided stream systems, lakes, and seasonal mudflats along the western interior of North America.
  • Allosaurus jimmadseni represents the earliest species of Allosaurus in the world.

Discovery

  • Allosaurus jimmadseni can be found in a geologic unit known as the Salt Wash Member of the Morrison Formation and its equivalents exposed in Colorado, Wyoming, and Utah.
  • The first specimen of Allosaurus jimmadseni was discovered in the National Park Service administered by Dinosaur National Monument in Uintah County, near Vernal, Utah.
  • Allosaurus jimmadseni was first discovered by George Engelmann of the University of Nebraska, Omaha on July 15, 1990 during a contracted paleontological inventory of the Morrison Formation of Dinosaur National Monument.
  • Another specimen of Allosaurus jimmadseni known as “Big Al,” was found on land administered by the U.S. Department of the Interior’s Bureau of Land Management in Wyoming.
  • Further specimens of Allosaurus jimmadseni have been subsequently recognized in the collections of various museums.
  • Allosaurus jimmadseni specimens are permanently housed in the collections of Dinosaur National Monument, Utah; the Museum of the Rockies, Bozeman, Montana; the Saurier Museum of Aathal, Switzerland; the South Dakota School of Mines, Rapid City, South Dakota; Brigham Young University’s Museum of Paleontology, Provo, Utah; and the United States National Museum (Smithsonian) Washington D.C.
  • These discoveries are the result of a continuing collaboration between the Natural History Museum of Utah, the National Park Service, and the Bureau of Land Management.

Excavation

  • The first skeleton of Allosaurus jimmadseni was excavated during the summers of 1990 to 1994 by staff of the National Park Service’s Dinosaur National Monument. The skeleton block was so heavy it required the use of explosives to remove surrounding rock and a helicopter to fly out the 2700 kg block. The head of the skeleton was missing
  • The first bones of Allosaurus jimmadseni discovered included toes and some tail vertebrae. Later excavation revealed most of an articulated skeleton missing the head and part of the tail.
  • The radioactive skull of the first specimen of Allosaurus jimmadseni, which had previously eluded discovery, was found in 1996 by Ramal Jones of the University of Utah using a radiation detector.

Preparation

  • It required seven years to fully prepare all of the bones of Allosaurus jimmadseni.
  • Much of the preparation was done by then Dinosaur National Monument employees Scott Madsen and Ann Elder, with some assistance from Dinosaur National Monument volunteers and students at Brigham Young University.

Story Source:

Materials provided by University of UtahNote: Content may be edited for style and length.


Journal Reference:

  1. Daniel J. Chure, Mark A. Loewen. Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North AmericaPeerJ, 2020; 8: e7803 DOI: 10.7717/peerj.7803

New feathered dinosaur shows dinosaurs grew up differently from birds

A new species of feathered dinosaur has been discovered in China, and described by American and Chinese authors and published today in the journal, The Anatomical Record.

The one-of-a-kind specimen offers a window into what the earth was like 120 million years ago. The fossil preserves feathers and bones that provide new information about how dinosaurs grew and how they differed from birds.

“The new dinosaur fits in with an incredible radiation of feathered, winged animals that are closely related to the origin of birds,” said Dr. Ashley Poust, who analyzed the specimens while he was a student at Montana State University and during his time as a Ph.D. student at University of California, Berkeley. Poust is now postdoctoral researcher at the San Diego Natural History Museum.

“Studying specimens like this not only shows us the sometimes-surprising paths that ancient life has taken, but also allows us to test ideas about how important bird characteristics, including flight, arose in the distant past.”

Scientists named the dinosaur Wulong bohaiensis. Wulong is Chinese for “the dancing dragon” and references the position of the beautifully articulated specimen.

About the Discovery

The specimen was found more than a decade ago by a farmer in China, in the fossil-rich Jehol Province, and since then has been housed in the collection of The Dalian Natural History Museum in Liaoning, a northeastern Chinese province bordering North Korea and the Yellow Sea. The skeletal bones were analyzed by Poust alongside his advisor Dr. David Varricchio from Montana State University while Poust was a student there.

Larger than a common crow and smaller than a raven, but with a long, bony tail which would have doubled its length, Wulong bohaiensis had a narrow face filled with sharp teeth. Its bones were thin and small, and the animal was covered with feathers, including a wing-like array on both its arms and legs and two long plumes at the end of its tail.

This animal is one of the earliest relatives of Velociraptor, the famous dromaeosaurid theropod dinosaur that lived approximately 75 million years ago. Wulong’s closest well-known relative would have been Microraptor, a genus of small, four-winged paravian dinosaurs.

The discovery is significant not only because it describes a dinosaur that is new to science, but also because it shows connection between birds and dinosaurs.

“The specimen has feathers on its limbs and tail that we associate with adult birds, but it had other features that made us think it was a juvenile,” said Poust. To understand this contradiction, the scientists cut up several bones of the new dinosaur to examine under a microscope. This technique, called bone histology, is becoming a regular part of the paleontology toolbox, but it’s still sometimes difficult to convince museums to let a researcher remove part of a nice skeleton. “Thankfully, our coauthors at the Dalian Natural History Museum were really forward thinking and allowed us to apply these techniques, not only to Wulong, but also to another dinosaur, a close relative that looked more adult called Sinornithosaurus.”

The bones showed that the new dinosaur was a juvenile. This means that at least some dinosaurs were getting very mature looking feathers well before they were done growing. Birds grow up very fast and often don’t get their adult plumage until well after they are full sized. Showy feathers, especially those used for mating, are particularly delayed. And yet here was an immature dinosaur with two long feathers extending beyond the tip of the tail.

“Either the young dinosaurs needed these tail feathers for some function we don’t know about, or they were growing their feathers really differently from most living birds,” explained Poust.

An additional surprise came from the second dinosaur the scientists sampled; Sinornithosaurus wasn’t done growing either. The bone tissue was that of an actively growing animal and it lacked an External Fundamental System: a structure on the outside of the bone that vertebrates form when they’re full size. “Here was an animal that was large and had adult looking bones: we thought it was going to be mature, but histology proved that idea wrong. It was older than Wulong, but seems to have been still growing. Researchers need to be really careful about determining whether a specimen is adult or not. Until we learn a lot more, histology is really the most dependable way.”

In spite of these cautions, Poust says there is a lot more to learn about dinosaurs.

“We’re talking about animals that lived twice as long ago as T. rex, so it’s pretty amazing how well preserved they are. It’s really very exciting to see inside these animals for the first time.”

About the Jehol Biota

The area in which the specimen was found is one of the richest fossil deposits in the world. The Jehol biota is known for the incredible variety of animals that were alive at the time. It is also one of the earliest bird-rich environments, where birds, bird-like dinosaurs, and pterosaurs all shared the same habitat.

“There was a lot of flying, gliding, and flapping around these ancient lakes,” says Poust. “As we continue to discover more about the diversity of these small animals it becomes interesting how they all might have fit into the ecosystem.” Other important changes were happening at the same time in the Early Cretaceous, including the spread of flowering plants. “It was an alien world, but with some of the earliest feathers and earliest flowers, it would have been a pretty one.”


Story Source:

Materials provided by San Diego Natural History MuseumNote: Content may be edited for style and length.