Who was king before Tyrannosaurus? Uzbek fossil reveals new top dino
Iconic tyrannosauroids like T. rex famously dominated the top of the food web at the end of the reign of the dinosaurs. But they didn’t always hold that top spot.
In a new study published in Royal Society Open Science, a research team led by the University of Tsukuba has described a new genus and species belonging to the Carcharodontosauria, a group of medium- to large-sized carnivorous dinosaurs that preceded the tyrannosauroids as apex predators.
The new dinosaur, named Ulughbegsaurus uzbekistanensis, was found in the lower Upper Cretaceous Bissekty Formation of the Kyzylkum Desert in Uzbekistan, and therefore lived about 90 million years ago. Two separate evolutionary analyses support classification of the new dinosaur as the first definitive carcharodontosaurian discovered in the Upper Cretaceous of Central Asia.
“We described this new genus and species based on a single isolated fossil, a left maxilla, or upper jawbone,” explains study first author Assistant Professor Kohei Tanaka. “Among theropod dinosaurs, the size of the maxilla can be used to estimate the animal’s size because it correlates with femur length, a well-established indicator of body size. Thus, we were able to estimate that Ulughbegsaurus uzbekistanensis had a mass of over 1,000 kg, and was approximately 7.5 to 8.0 meters in length, greater than the length of a full-grown African elephant.”
This size greatly exceeds that of any other carnivore known from the Bissekty Formation, including the small-sized tyrannosauroid Timurlengia described from the same formation. Therefore, the newly named dinosaur likely topped the food web in its early Late Cretaceous ecosystem.
The genus’s namesake is fittingly regal; Ulughbegsaurus is named for Ulugh Beg, the 15th century mathematician, astronomer, and sultan of the Timurid Empire of Central Asia. The species is named for the country where the fossil was discovered.
Before the Late Cretaceous, carcharodontosaurians like Ulughbegsaurus disappeared from the paleocontinent that included Central Asia. This disappearance is thought to have been related to the rise of tyrannosauroids as apex predators, but this transition has remained poorly understood because of the scarcity of relevant fossils.
Senior author Professor Yoshitsugu Kobayashi at the Hokkaido University Museum explains “The discovery of Ulughbegsaurus uzbekistanensis fills an important gap in the fossil record, revealing that carcharodontosaurians were widespread across the continent from Europe to East Asia. As one of the latest surviving carcharodontosaurians in Laurasia, this large predator’s coexistence with a smaller tyrannosauroid reveals important constraints on the transition of the apex predator niche in the Late Cretaceous.”
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Journal Reference:
- Kohei Tanaka, Otabek Ulugbek Ogli Anvarov, Darla K. Zelenitsky, Akhmadjon Shayakubovich Ahmedshaev, Yoshitsugu Kobayashi. A new carcharodontosaurian theropod dinosaur occupies apex predator niche in the early Late Cretaceous of Uzbekistan. Royal Society Open Science, 2021; 8 (9): 210923 DOI: 10.1098/rsos.210923
500-million-year-old fossil represents rare discovery of ancient animal in North America
Many scientists consider the “Cambrian explosion” — which occurred about 530-540 million years ago — as the first major appearance of many of the world’s animal groups in the fossil record. Like adding pieces to a giant jigsaw puzzle, each discovery dating from this time period has added another piece to the evolutionary map of modern animals. Now, researchers at the University of Missouri have found a rare, 500-million-year-old “worm-like” fossil called a palaeoscolecid, which is an uncommon fossil group in North America. The researchers believe this find, from an area in western Utah, can help scientists better understand how diverse the Earth’s animals were during the Cambrian explosion.
Jim Schiffbauer, an associate professor of geological sciences in the MU College of Arts and Science and one of the study’s co-authors, said that while this fossil has the same anatomical organization as modern worms, it doesn’t exactly match with anything we see on modern Earth.
“This group of animals are extinct, so we don’t see them, or any modern relatives, on the planet today,” Schiffbauer said. “We tend to call them ‘worm-like’ because it’s hard to say that they perfectly fit with annelids, priapulids, or any other types of organism on the planet today that we would generally call a “worm.” But palaeoscolecids have the same general body plan, which in the history of life has been an incredibly successful body plan. So, this is a pretty cool addition because it expands the number of worm-like things that we know about from 500 million years ago in North America and adds to our global occurrences and diversity of the palaeoscolecids.”
At the time, this palaeoscolecid was likely living on an ocean floor, said Wade Leibach, an MU graduate teaching assistant in the College of Arts and Science, and lead author on the study.
“It is the first known palaeoscolecid discovery in a certain rock formation — the Marjum Formation of western Utah — and that’s important because this represents one of only a few palaeoscolecid taxa in North America,” Leibach said. “Other examples of this type of fossil have been previously found in much higher abundance on other continents, such as Asia, so we believe this find can help us better understand how we view prehistoric environments and ecologies, such as why different types of organisms are underrepresented or overrepresented in the fossil record. So, this discovery can be viewed from not only the perspective of its significance in North American paleontology, but also broader trends in evolution, paleogeography and paleoecology.”
Leibach, who switched his major from biology to geology after volunteering to work with the invertebrate paleontology collections at the University of Kansas, began this project as an undergraduate student by analyzing a box of about a dozen fossils in the collections of the KU Biodiversity Institute. Initially, Leibach and one of his co-authors, Anna Whitaker, who was a graduate student at KU at the time and now is at the University of Toronto-Mississauga, analyzed each fossil using a light microscope, which identified at least one of the fossils to be a palaeoscolecid.
Leibach worked with Julien Kimmig, who was at the KU Biodiversity Institute at the time and is now at Penn State University, to determine that, in order to be able to confirm their initial findings, he would need the help of additional analyses provided by sophisticated microscopy equipment located at the MU X-ray Microanalysis Core, which is directed by Schiffbauer. Using the core facility at MU, Leibach focused his analysis on the indentations left in the fossil by the ancient animal’s microscopic plates, which are characteristic of the palaeoscolecids.
“These very small mineralized plates are usually nanometers-to-micrometers in size, so we needed the assistance of the equipment in Dr. Schiffbauer’s lab to be able to study them in detail because their size, orientation and distribution is how we classify the organism to the genus and species levels,” Leibach said.
Leibach said the team found a couple reasons about why this particular fossil may be found in limited quantities in North America as compared to other parts of the world. They are:
- Geochemical limitations or different environments that may be more predisposed to preserving these types of organisms.
- Ecological competition, which may have driven this type of organism to be less competitive or less abundant in certain areas.
The new taxon is named Arrakiscolex aasei after the fictional planet Arrakis in the novel “Dune” by Frank Herbert, which is inhabited by a species of armored worm and the collector of the specimens Arvid Aase.
The study, “First palaeoscolecid from the Cambrian (Miaolingian, Drumian) Marjum Formation of western Utah,” was published in Acta Palaeontologica Polonica, an international quarterly journal which publishes papers from all areas of paleontology. Funding was provided by a National Science Foundation CAREER grant (1652351), a National Science Foundation Earth Sciences Instrumentation and Facilities grant (1636643), a University of Kansas Undergraduate Research grant, a student research grant provided by the South-Central Section of the Geological Society of America, and the J. Ortega-Hernández Laboratory for Invertebrate Palaeobiology at Harvard University. The study’s authors would like to thank Arvid Aase and Thomas T. Johnson for donating the specimens analyzed in the study.The new taxon is named Arrakiscolex aasei after the fictional planet Arrakis in the novel “Dune” by Frank Herbert, which is inhabited by a species of armored worm and the collector of the specimens Arvid Aase.
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Materials provided by University of Missouri-Columbia. Note: Content may be edited for style and length.
Journal Reference:
- Wade Leibach, Rudy Lerosey-Aubril, Anna Whitaker, James Schiffbauer, Julien Kimmig. First palaeoscolecid from the Cambrian (Miaolingian, Drumian) Marjum Formation of western Utah. Acta Palaeontologica Polonica, 2021; 66 DOI: 10.4202/app.00875.2021
Massive new animal species discovered in half-billion-year-old Burgess Shale
ROM palaeontologists unearth one of the largest radiodonts of the Cambrian explosion
Palaeontologists at the Royal Ontario Museum (ROM) have uncovered the remains of a huge new fossil species belonging to an extinct animal group in half-a-billion-year-old Cambrian rocks from Kootenay National Park in the Canadian Rockies. The findings were announced on September 8, 2021, in a study published in Royal Society Open Science.
Named Titanokorys gainesi, this new species is remarkable for its size. With an estimated total length of half a meter, Titanokorys was a giant compared to most animals that lived in the seas at that time, most of which barely reached the size of a pinky finger.
“The sheer size of this animal is absolutely mind-boggling, this is one of the biggest animals from the Cambrian period ever found,” says Jean-Bernard Caron, ROM’s Richard M. Ivey Curator of Invertebrate Palaeontology.
Evolutionarily speaking, Titanokorys belongs to a group of primitive arthropods called radiodonts. The most iconic representative of this group is the streamlined predator Anomalocaris, which may itself have approached a metre in length. Like all radiodonts, Titanokorys had multifaceted eyes, a pineapple slice-shaped, tooth-lined mouth, a pair of spiny claws below its head to capture prey and a body with a series of flaps for swimming. Within this group, some species also possessed large, conspicuous head carapaces, with Titanokorys being one of the largest ever known.
“Titanokorys is part of a subgroup of radiodonts, called hurdiids, characterized by an incredibly long head covered by a three-part carapace that took on myriad shapes. The head is so long relative to the body that these animals are really little more than swimming heads,” added Joe Moysiuk, co-author of the study, and a ROM-based Ph.D. student in Ecology & Evolutionary Biology at the University of Toronto.
Why some radiodonts evolved such a bewildering array of head carapace shapes and sizes is still poorly understood and was likely driven by a variety of factors, but the broad flattened carapace form in Titanokorys suggests this species was adapted to life near the seafloor.
“These enigmatic animals certainly had a big impact on Cambrian seafloor ecosystems. Their limbs at the front looked like multiple stacked rakes and would have been very efficient at bringing anything they captured in their tiny spines towards the mouth. The huge dorsal carapace might have functioned like a plough,” added Dr. Caron, who is also an Associate Professor in Ecology & Evolutionary Biology and Earth Sciences at the University of Toronto, and Moysiuk’s Ph.D. advisor.
All fossils in this study were collected around Marble Canyon in northern Kootenay National Park by successive ROM expeditions. Discovered less than a decade ago, this area has yielded a great variety of Burgess Shale animals dating back to the Cambrian period, including a smaller, more abundant relative of Titanokorys named Cambroraster falcatusin reference to its Millennium Falcon-shaped head carapace. According to the authors, the two species might have competed for similar bottom-dwelling prey.
The Burgess Shale fossil sites are located within Yoho and Kootenay National Parks and are managed by Parks Canada. Parks Canada is proud to work with leading scientific researchers to expand knowledge and understanding of this key period of earth history and to share these sites with the world through award-winning guided hikes. The Burgess Shale was designated a UNESCO World Heritage Site in 1980 due to its outstanding universal value and is now part of the larger Canadian Rocky Mountain Parks World Heritage Site.
The discovery of Titanokorys gainesi was profiled in the CBC’s The Nature of Things episode “First Animals.” These and other Burgess Shale specimens will be showcased in a new gallery at ROM, the Willner Madge Gallery, Dawn of Life, opening in December 2021.
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Materials provided by Royal Ontario Museum. Note: Content may be edited for style and length.
Journal Reference:
- J.-B. Caron, J. Moysiuk. A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity. Royal Society Open Science, 2021; 8 (9): 210664 DOI: 10.1098/rsos.210664
Newly identified mosasaur was fish-hunting monster
Researchers name species for husband-wife paleontologists in Kansas
Researchers at the University of Cincinnati identified a new species of mosasaur — an 18-foot-long fish-eating monster that lived 80 million years ago.
UC assistant professor-educator Takuya Konishi and his student, UC graduate Alexander Willman, named the mosasaur Ectenosaurus everhartorum after paleontologists Mike and Pamela Everhart. The mosasaur inhabited the Western Interior Seaway in what today is western Kansas.
The discovery was announced this week in the Canadian Journal of Earth Sciences.
The newly identified mosasaur marks only the second species in the genus Ectenosaurus.
“Mosasaurs in western Kansas have been well sampled and well researched. Those two factors create tall odds when you try to find something new,” Konishi said.
Mosasaurs were enormous marine reptiles, some as big as school buses. They inhabited oceans around the world during the Cretaceous period around the time of Tyrannosaurus rex. If Ectenosaurus clidastoides with its long, slender jaws resembles a gharial crocodile, Konishi said the new species is closer to a false gharial crocodile with notably blunter jaws.
Konishi, who teaches in the Biological Sciences Department of UC’s College of Arts and Sciences, first encountered the fossil in 2004 while working as a graduate student in systematics and evolution. Konishi was studying fossils of Platecarpus, a different genus of mosasaur in storage at Fort Hays State University’s Sternberg Museum of Natural History, when he recognized something odd about one specimen.
“It wasn’t a platecarpus. The frontal bone above the eye socket was much longer. The bones of Platecarpus should have had a broader triangle,” he said. “That was one telltale sign.”
Konishi suspected the specimen was a type of ectenosaur, only one species of which had been identified. But the teeth seemed all wrong. The now-empty sockets that would have contained the mosasaur’s sharp, curved teeth in the unidentified specimen would have extended around the front of its mouth, unlike other recognized species that has a toothless rostrum, the bony protuberance at the front of the mouth.
For years, the fossils puzzled him.
“Some things just stick in your mind and they’re hard to let go,” he said.
But the mystery would have to wait because Konishi was busy finishing his doctoral degree and launching an academic career that would bring him to UC’s College of Arts and Sciences.
The first mosasaur fossils were found in the Netherlands a half-century before anyone used the term “dinosaur.” Mosasaurs began to capture the nation’s attention after the Civil War when the nation’s premier paleontologists, Othniel Charles Marsh and Edward Drinker Cope, began to study Cretaceous limestone in Kansas in a partnership that became a bitter public feud. Since then, Kansas has become world-renowned for mosasaur research.
Generations of experts have come to Kansas to study its specimens, which are on display at museums around the world.
“It’s a famous place for mosasaur research. It’s quite well known,” Konishi said. “So I thought I don’t have to be the guy to place a stake. I’m sure someone will catch it. But nobody did.”
Ectenosaur is unusual for how few specimens have been found in the genus compared to other mosasaurs, Konishi said.
“In western Kansas we have over 1,500 mosasaur specimens. Out of those we can only find one specimen each representing these two species of ectenosaur,” Konishi said. “That’s sort of crazy.”
When Konishi confirmed with the Sternberg Museum that no other researchers were studying the specimen, he asked them to ship the fossils to UC. When he opened the carefully bubble-wrapped contents, his initial impressions were confirmed.
“By then I had looked at all the other known Platecarpus specimens under the sun, as it were. And this specimen was distinct from the others,” he said. “To me it was so obvious.”
At the same time, Konishi’s student Willman inquired about working on a research project. He received a UC Undergraduate STEM Experience grant to help with the taxonomic identification.
“I was beyond excited to be part of the discovery,” Willman said.
The third author on the study, Michael Caldwell, is a professor of biology at the University of Alberta, Edmonton.
Willman illustrated the fossils in painstaking detail to help scientists understand the morphological differences that make the mosasaur unique.
“I was very happy with how he brought these broken bones to life,” Konishi said. “It helped make our case very convincing to anyone that this is something new that warrants the establishment of a new taxon.”
The researchers dedicated the project to the late Dale Russell, whose work has had a profound impact in North American mosasaur paleontology, Konishi said. But they named the mosasaur for the Everharts, a Kansas couple who have spent more than 30 years sharing their fossils with museums and leading research field trips in the fossil-rich Smoky Hill Chalk.
“We’re still in a little bit of shock at the news. It’s very exciting,” Pamela Everhart said.
“It’s a great honor,” said Mike Everhart, author of “Oceans of Kansas” about mosasaurs and other prehistoric life that inhabited the Western Interior Seaway during the Cretaceous Period.
Mosasaurs are very special to him, he said.
“The oceans would not have been a safe place for swimming in the Cretaceous,” he said. “Mosasaurs were the top predator in the ocean during those times.”
Story Source:
Materials provided by University of Cincinnati. Original written by Michael Miller. Note: Content may be edited for style and length.
Journal Reference:
- Alexander J. Willman, Takuya Konishi, Michael W. Caldwell. A new species of Ectenosaurus (Mosasauridae: Plioplatecarpinae) from western Kansas, USA, reveals a novel suite of osteological characters for the genus. Canadian Journal of Earth Sciences, 2021; 741 DOI: 10.1139/cjes-2020-0175
Tyrannosaurus rex’s jaw had sensors to make it an even more fearsome predator
Tyrannosaurus rex was not just a huge beast with a big bite, it had nerve sensors in the very tips of its jaw enabling it to better detect — and eat — its prey, a new study published in the peer-reviewed journal Historical Biology today finds.
“T. rex was an even more fearsome predator than previously believed,” explains lead author Dr Soichiro Kawabe, from the Institute of Dinosaur Research at Fukui Prefectural University, in Japan.
“Our findings show the nerves in the mandible (an area of the jaw) of Tyrannosaurus rex is more complexly distributed than those of any other dinosaurs studied to date, and comparable to those of modern-day crocodiles and tactile-foraging birds, which have extremely keen senses.
“What this means is that T. rex was sensitive to slight differences in material and movement; it indicates the possibility that it was able to recognize the different parts of their prey and eat them differently depending on the situation.
“This completely changes our perception of T. rex as a dinosaur that was insensitive around its mouth, putting everything and anything in biting at anything and everything including bones.”
Whilst the morphology of vessels and nerves in the jaw have been analysed in several fossil reptiles, this study is the very first investigation of the internal structure of the mandible of T. rex.
Dr Kawabe, who was joined by Dr Soki Hattori Assistant Professor at the Institute of Dinosaur Research, used computed tomography (CT) to analyse and reconstruct the distribution neurovascular canal of a fossil mandible of T. rex, which was originally found in Hell Creek Formation, Montana.
They then compared their reconstruction to other dinosaurs such as Triceratops, as well as living crocodiles and birds.
This enabled the researchers to describe the well-preserved canals that houses the vessels and nerves in dentary of Tyrannosaurus rex.
“The present study reveals the presence of neurovascular canals with complex branching in the lower jaw of Tyrannosaurus, especially in the anterior region of the dentary, and it is assumed that a similarly complex branching neurovascular canal would also be present in its upper jaw,” says Dr Kawabe.
He added: “The neurovascular canal with branching pattern as complex as that of the extant crocodilians and ducks, suggests that the trigeminal nervous system in Tyrannosaurus probably functioned as a sensitive sensor in the snout.
“It must be noted that the sensitivity of the snout in Tyrannosaurus may not have been as enhanced as that of the crocodilians because Tyrannosaurus lacks the thick neural tissue occupying the neurovascular canal unlike extant crocodiles.
“Nevertheless, the sensitivity of the snout of Tyrannosaurus was considerably greater than that of the ornithischian dinosaurs compared in this study.”
The results of the paper are consistent with analyses of the skull surface of another tyrannosaurid, Daspletosaurus, and the neurovascular canal morphology within the maxilla of allosaurid Neovenator, which indicate that the facial area of theropods may have been highly sensitive.
“These inferences also suggest that, in addition to predation, tyrannosaurids’ jaw tips were adapted to perform a series of behaviours with fine movements including nest construction, parental care, and intraspecific communication,” Dr Hattori adds.
Limitations of the study include the team not analysing the full mandible area of T. rex and other dinosaurs used for comparison, however as the proportion not researched is insignificant, the trend shown “should be a reasonable estimate.”
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Materials provided by Taylor & Francis Group. Note: Content may be edited for style and length.
Journal Reference:
- Soichiro Kawabe, Soki Hattori. Complex neurovascular system in the dentary of Tyrannosaurus. Historical Biology, 2021; 1 DOI: 10.1080/08912963.2021.1965137