Ancient Iowan super predator got big by front-loading its growth in its youth

Co-author Ben Otoo with a life-size illustration of Whatcheeria.
Photo Credit: Courtesy of Ben Otoo.

The Field Museum in Chicago is home to the best, most-complete fossils of a prehistoric superpredator-- but one that lived hundreds of millions of years before SUE the T. rex. Whatcheeria was a six-foot-long lake-dwelling creature with a salamander-like body and a long, narrow head; its fossils were discovered in a limestone quarry near the town of What Cheer, Iowa. There are around 350 Whatcheeria specimens, ranging from single bones to complete skeletons, that have been unearthed, and every last one of them resides in the Field Museum’s collections. In a new study in Communications Biology, these specimens helped reveal how Whatcheeria grew big enough to menace its fishy prey: instead of growing “slow and steady” the way that many modern reptiles and amphibians do, it grew rapidly in its youth.

“If you saw Whatcheeria in life, it would probably look like a big crocodile-shaped salamander, with a narrow head and lots of teeth,” says Ben Otoo, a co-author of the study and a PhD student at the University of Chicago and the Field Museum. “If it really curled up, probably to an uncomfortable extent, it could fit in your bathtub, but neither you nor it would want it to be there.”

World’s oldest meal offers food for thought

Professor Jochen Brocks (left) and Dr Ilya Bobrovskiy
Photo Credit: ANU

The contents of the last meal consumed by the earliest animals known to inhabit Earth more than 550 million years ago has unearthed new clues about the physiology of our earliest animal ancestors, according to scientists from The Australian National University (ANU).

Ediacara biota are the world's oldest large organisms and were first discovered in the Ediacara Hills in South Australia's Flinders Ranges. They date back 575 million years.

ANU researchers found the animals ate bacteria and algae that was sourced from the ocean floor. The findings, published in Current Biology, reveal more about these strange creatures, including how they were able to consume and digest food.

The scientists analyzed ancient fossils containing preserved phytosterol molecules -- a type of fat found in plants -- that remained from the animals' last meal. By examining the molecular remains of what the animals ate, the researchers were able to confirm the slug-like organism, known as Kimberella, had a mouth and a gut and digested food the same way modern animals do. The researchers say it was likely one of the most advanced creatures of the Ediacarans.

Scientists estimate the weight of two giant extinct amphibians

Artist’s reconstruction of Eryops megacephalus (left) and Paracyclotosaurus davidi (right).
Image Credit: Josè Vitor Silva.

A team of Australian scientists led by UNSW Sydney paleontologist Lachlan Hart has calculated the body mass of two ancient amphibians.

The last of the temnospondyls – amphibians that look more like crocodiles – became extinct during the Cretaceous period, about 120 million years ago, after thriving on Earth for more than 200 million years.

Now a team of scientists led by Lachlan Hart, a paleontologist and PhD candidate in the School of Biological, Earth & Environmental Sciences at UNSW Sydney, has assessed various methods of estimating the weight of these unique extinct animals. The team’s study is published in the journal Paleontology.

“Estimating mass in extinct animals presents a challenge, because we can’t just weigh them like we could with a living thing,” said Mr. Hart. “We only have the fossils to tell us what an animal looked like, so we often need to look at living animals to get an idea about soft tissues, such as fat and skin.”

Rapid fluctuations in oxygen levels coincided with Earth’s first mass extinction

Nevin Kozik during fieldwork to investigate how rapid changes in marine oxygen levels may have played a significant role in driving Earth’s first mass extinction.
Photo Credit: Courtesy of Nevin Kozik

Rapid changes in marine oxygen levels may have played a significant role in driving Earth’s first mass extinction, according to a new study led by Florida State University researchers.

About 443 million years ago, life on Earth was undergoing the Late Ordovician mass extinction, or LOME, which eliminated about 85% of marine species. Scientists have long studied this mass extinction and continue to investigate its possible causes, such as reduced habitat loss in a rapidly cooling world or persistent low-oxygen conditions in the oceans.

By measuring isotopes of the element thallium — which shows special sensitivity to changes in oxygen in the ancient marine environment — the research team found that previously documented patterns of this mass extinction coincided with an initial rapid decrease in marine oxygen levels followed by a rapid increase in oxygen. Their work is published online in the journal Science Advances.

“Paleontologists have noted that there were several groups of organisms, such as graptolites and brachiopods, that started to decline very early in this mass extinction interval, but we didn’t really have any good evidence of an environmental or climate signature to tie that early decline of these groups to a particular mechanism,” said co-author Seth Young, an associate professor in the Department of Earth, Ocean and Atmospheric Science. “This paper can directly link that early phase of extinction to changes in oxygen. We see a marked change in thallium isotopes at the same time these organisms start their steady decline into the main phase of the mass extinction event.”

Prehistoric predator? Artificial intelligence says no

Artificial intelligence has proven vital in identifying a mysterious Aussie dinosaur
Image Credit: Dr Anthony Romilio

Artificial intelligence has revealed that prehistoric footprints thought to be made by a vicious dinosaur predator were in fact from a timid herbivore.

In an international collaboration, University of Queensland paleontologist Dr Anthony Romilio used AI pattern recognition to re-analyze footprints from the Dinosaur Stampede National Monument, south-west of Winton in Central Queensland.

“Large dinosaur footprints were first discovered back in the 1970s at a track site called the Dinosaur Stampede National Monument, and for many years they were believed to be left by a predatory dinosaur, like Australovenator, with legs nearly two meters long,” said Dr Romilio.

“The mysterious tracks were thought to be left during the mid-Cretaceous Period, around 93 million years ago.

“But working out what dino species made the footprints exactly – especially from tens of millions of years ago – can be a pretty difficult and confusing business.

Researchers Solve Hundred-Year-Old Botanical Mystery that was Key to the Spread of Plant Life on Land

Plant material from Yale-Myers Forest and YSE greenhouses were used to study how their vascular systems are constructed and how they compare to the extinct plants from the fossil record. Without developing their vascular systems, plants would largely still look like mosses. Shown here: Huperzia lucidula, also known as Shining club-moss.
Photo Credit: courtesy of Craig Brodersen Lab.

The earliest land plants were small — just a few centimeters tall at most — and restricted to moist, boggy habitats around streams and ponds. Around 400 million years ago, however, plants developed vascular systems to extract water more efficiently from the soil and use it for photosynthesis, a transition that would forever alter the Earth’s atmosphere and ecosystems. A team of researchers have now solved a 100-year-old paleontology mystery: How did ancient plants emerge from swamps and riverbanks to new habitats with limited access to water?

In a new paper published in Science, YSE Professor of Plant Physiological Ecology Craig Brodersen and his research team, including lead author Martin Bouda ’17 PhD, ’12 MPhil and Kyra A. Prats ’22 PhD, ’16 MFS, discovered that a simple change in the vascular system of plants made them more drought-resistant, which opened up new landscapes for exploration.

The research was spurred by a century-long debate about why the simple, cylindrical vascular system of the earliest land plants rapidly changed to more complex shapes. In the 1920s, scientists noted this increasing complexity in the fossil record but were not able to pinpoint the reason — if there even was one — for the evolutionary changes.

New pterosaur species found in sub-Saharan Africa

SMU paleontologists helped find a new species of pterosaurs in Angola, where fossils of other large marine animals have been found. E. otyikokolo can be seen flying above the ocean in the ancient picture.
Artwork Credit: Karen Carr Studio.

With wings spanning nearly 16 feet, a new species of pterosaurs has been identified from the Atlantic coast of Angola.

An international team, including two vertebrate paleontologists from SMU, named the new genus and species Epapatelo otyikokolo. This flying reptile of the dinosaur age was found in the same region of Angola as fossils from large marine animals currently on display at the Smithsonian’s National Museum of Natural History.

Pterosaur fossils that date back to the Late Cretaceous are extremely rare in sub-Saharan Africa, said team member Michael J. Polcyn, research associate in the Huffington Department of Earth Sciences and senior research fellow, ISEM at SMU (Southern Methodist University).

“This new discovery gives us a much better understanding of the ecological role of the creatures that were flying above the waves of Bentiaba, on the west coast of Africa, approximately 71.5 million years ago,” Polcyn said.

Renowned paleontologist Louis L. Jacobs, SMU professor emeritus of earth sciences and president of ISEM, an interdisciplinary institute at the university, also collaborated on the research. The team’s findings were published in the journal Diversity.

500 million year-old fossils reveal answer to evolutionary riddle

Fossil specimen (left) and diagram (right) of Gangtoucunia aspera preserving soft tissues, including the gut and tentacle.
Image Credit: Luke Parry and Guangxu Zhang.

An exceptionally well-preserved collection of fossils discovered in eastern Yunnan Province, China, has enabled researchers to solve a centuries-old riddle in the evolution of life on earth, revealing what the first animals to make skeletons looked like. The results have been published today in Proceedings of the Royal Society B.

The first animals to build hard and robust skeletons appear suddenly in the fossil record in a geological blink of an eye around 550-520 million years ago during an event called the Cambrian Explosion. Many of these early fossils are simple hollow tubes ranging from a few millimetres to many centimetres in length. However, what sort of animals made these skeletons was almost completely unknown, because they lack preservation of the soft parts needed to identify them as belonging to major groups of animals that are still alive today.

The new collection of 514-million-year-old fossils includes four specimens of Gangtoucunia aspera with soft tissues still intact, including the gut and mouthparts. These reveal that this species had a mouth fringed with a ring of smooth, unbranched tentacles about 5 mm long. It’s likely that these were used to sting and capture prey, such as small arthropods. The fossils also show that Gangtoucunia had a blind-ended gut (open only at one end), partitioned into internal cavities, that filled the length of the tube.

Jurassic ichthyosaurs divided food resources to co-exist, researchers find

The skull of Ichthyosaurs Hauffiopteryx typicus from the Strawberry Bank Lagerstätt, one of the specimens that were the subject of this study.
Credit: Bath Royal Literary and Scientific Institution Collections

Early Jurassic ichthyosaur juveniles show predatory specializations, scientists at the University of Bristol have revealed.

Their findings, published today in Journal of Anatomy, suggest that physical differences in their snouts show they evolved to have different diets and were not competing for the same resource.

Ichthyosaurs, the classic ‘sea dragons’, were dolphin-shaped marine predators that fed on fish and squid-like swimming shellfish. The ichthyosaurs of the Lower Jurassic, some 185 million years ago, are renowned because the first specimens were found over 200 years ago at Lyme Regis in southern England, by the celebrated fossil collector and paleontologist Mary Anning. Some of her specimens have long, slender snouts and others have short, broad snouts.

“Functional studies need excellent three-dimensional specimens,” said Matt Williams of Bath Royal Literary and Scientific Institution, “and the Lower Jurassic ichthyosaur fossils from Strawberry Bank in Ilminster are just that. Mary Anning’s fossils are amazing, but they are mostly squashed flat.”

What caused the holes in SUE the T. rex ’s jaw? Probably not an infection

Field Museum paleontologist Jingmai O’Connor with SUE the T. rex’s skull.
Resized Image using AI by SFLORG
Credit: Katharine Uhrich, Field Museum

SUE the T. rex is one of the most complete, best-preserved Tyrannosaurus rex specimens ever found. That level of preservation helps reveal details about SUE’s life. For instance, SUE lived to a ripe old age of about thirty-three, and in those years, suffered their fair share of injuries. SUE’s most mysterious ailment might be the holes in their jawbone. These holes, some the diameter of a golf ball, dot the back half of the left lower jaw. It’s not clear what caused them, but similar injuries have been found in other T. rex fossils. In a new study published in Cretaceous Research, scientists showed that one of the popular theories-- that SUE had suffered an infection from a protozoan parasite-- couldn’t be true.

“These holes in SUE’s jaw have been a mystery for decades,” says Jingmai O’Connor, the associate curator of fossil reptiles at Chicago’s Field Museum and a co-author of the study. “Nobody knows how they formed, and there have been lots of guesses.”

One early hypothesis was that SUE suffered from a fungus-like bacterial infection, but that was later shown to be unlikely. It was re-hypothesized that SUE had a protozoan infection. Protozoans are microbes with more complex cell structures than bacteria. There are lots of protozoan-caused maladies out there; one common such disease is called trichomoniasis, caused by a microbe called Trichomonas vaginalis. Humans can get infected with trichomoniasis as an STD, but other animals can catch it too.

What a reptile’s bones can teach us about Earth’s perilous past

An illustration of how Palacrodon may have looked.
Credit: K.M. Jenkins

An extinct reptile’s oddly shaped chompers, fingers, and ear bones may tell us quite a bit about the resilience of life on Earth, according to a new study.

In fact, paleontologists at Yale, Sam Houston State University, and the University of the Witwatersrand say the 250-million-year-old reptile, known as Palacrodon, fills in an important gap in our understanding of reptile evolution. It’s also a signal that reptiles, plants, and ecosystems may have fared better or recovered more quickly than previously thought after a mass extinction event wiped out most of the plant and animal species on the planet.

“We now know that Palacrodon comes from one of the last lineages to branch off the reptile tree of life before the evolution of modern reptiles,” said Kelsey Jenkins, a doctoral student in Yale’s Department of Earth and Planetary Sciences in the Faculty of Arts and Sciences and first author of the study, which appears in the Journal of Anatomy. “We also know that Palacrodon lived in the wake of the most devastating mass extinction in Earth’s history.”

That would be the Permian-Triassic extinction event, which occurred 252 million years ago. Known as “the Great Dying,” it killed off 70% of terrestrial species and 95% of marine species.

Although a large number of reptile species eventually bounced back from this extinction event, the details of how that happened are murky. Researchers have spent decades trying to fill in the gaps in our understanding of key adaptations that enabled reptiles to flourish after the Permian-Triassic extinction — and what those adaptations may reveal about the ecosystems where they lived.

Paleontologists Found Mammoth Baby, Ancient Bear Teeth, and Lair of Cave Hyenas

Scientists will open a new expedition season in spring.
Photo credit: TASS-Ural Press Center / Vladislav Burnashev

Paleontologists of Ural Federal University and the Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Sciences during summer expeditions found a large number of ancient bones, teeth, as well as wool and skin of a mammoth baby. The study of remains will allow us to recreate the specifics of the flora and fauna of ancient times in detail and to understand the specifics of animal nutrition. Scientists told about the results of summer expeditions at a press conference in TASS.

On the Gyda Peninsula (Far North), paleontologists found the well-preserved remains of a mammoth baby. The uniqueness of the discovery is its age - it is a six-year-old mammoth baby. If previously only single bones were found, now the researchers have found material that will help study mammoth babies, said Pavel Kosintsev, a leading expert of the Laboratory of Natural Science Methods in Humanities of UrFU, a Senior Researcher of the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences.

Ancient 'Shark' from China Is Humans' Oldest Jawed Ancestor

Life reconstruction of Fanjingshania renovata.
Image Credit: ZHANG Heming)

Paleontologists discover a 439-million-year-old 'shark' that forces us to rethink the timeline of vertebrate evolution

Living sharks are often portrayed as the apex predators of the marine realm. Paleontologists have been able to identify fossils of their extinct ancestors that date back hundreds of millions of years to a time known as the Palaeozoic period. These early "sharks," known as acanthodians, bristled with spines. In contrast to modern sharks, they developed bony "armor" around their paired fins.

A recent discovery of a new species of acanthodian from China surprised scientists with its antiquity. The find predates by about 15 million years the earliest acanthodian body fossils and is the oldest undisputed jawed fish.

These findings were published in Nature.

Reconstructed from thousands of tiny skeletal fragments, Fanjingshania, named after the famous UNESCO World Heritage Site Fanjingshan, is a bizarre fish with an external bony "armor" and multiple pairs of fin spines that set it apart from living jawed fish, cartilaginous sharks and rays, and bony ray- and lobe-finned fish.

Dead fish breathe new life into the evolutionary origin of fins and limbs

The holotype specimen of the fossil Tujiaaspis vividus from 436 million year old rocks of Hunan Province and Chongqing, China.
Credit: Zhikun Gai

A trove of fossils in China, unearthed in rock dating back some 436 million years, have revealed for the first time that the mysterious galeaspids, a jawless freshwater fish, possessed paired fins.

The discovery, by an international team, led by Min Zhu of the Institute of Vertebrate Paleontology and Palaeoanthropology, Bejiing and Professor Philip Donoghue from the University of Bristol’s School of Earth Sciences, shows the primitive condition of paired fins before they separated into pectoral and pelvic fins, the forerunner to arms and legs.

Until now, the only surviving fossils of galeaspids were heads, but these new fossils originating in the rocks of Hunan Province and Chongqing and named Tujiaaspis after the indigenous Tujia people who live in this region, contain their whole bodies.

Theories abound on the evolutionary beginnings of vertebrate fins and limbs – the evolutionary precursors of arms and legs - mostly based on comparative embryology. There is a rich fossil record, but early vertebrates either had fins or they didn’t. There was little evidence for their gradual evolution.

Fossil eggs show dinosaur decline before extinction

Artist’s depiction of Late Cretaceous oviraptorosaurs, hadrosaurs, and tyrannosaurs living in central China
Credit: IVPP 

Nearly 66 million years ago, a large asteroid hit Earth and contributed to the global extinction of dinosaurs, leaving birds as their only living descendants.

Scientists know that a wide variety of dinosaurs lived around the world at the end of the Cretaceous period just before their extinction. However, scientists have debated whether dinosaurs were at their zenith or already in decline prior to their demise. In other words, did dinosaurs go out with a bang or a whimper?

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, along with their collaborators, now have an answer. They've found evidence to support the hypothesis that dinosaurs were not very diverse before their extinction and had declined overall during the last part of the Cretaceous.

Their findings were published in PNAS on Sept. 19.

Most of the scientific data on the last days of the dinosaurs comes from North America. Although some published studies suggest that dinosaur populations there were thriving quite well before extinction, other more detailed research has suggested that dinosaurs were instead in decline, which set the stage for their eventual mass extinction.

Scientists discover new ant species

Three-dimensional image of the previously unknown extinct ant species.
Illustration credit: Hammel/Lauströer

An international team of scientists has discovered a previously unknown extinct ant species encased in a unique piece of amber from Africa. Using the X-ray light source PETRA III at the German Electron Synchrotron (DESY) in Hamburg the researchers, from Friedrich Schiller University Jena, the University of Rennes in France, the University of Gdansk in Poland, as well as the Helmholtz-Zentrum Hereon in Geesthacht, Germany, had examined the critical fossil remains from 13 individual animals in the amber and realized that they could not be attributed to any previously known species. The name given to the new species and genus is †Desyopone hereon gen. et sp. nov. In this way, the scientists are honoring the two research institutions involved – DESY and Hereon – which contributed significantly to this find with the help of modern imaging techniques. Ultimately, it was only possible to identify the new species and genus through the combination of extensive phenotype data from scans and recent findings from genome analyses of living ants. The team reports on its discovery in the research journal “Insects”.

30-million-year-old amphibious beaver fossil is oldest ever found

A comparison of anklebones from the giant beaver and the newly identified species, Microtheriomys articulaquaticus, at the same scale.
Credit: Jonathan Calede / Ohio State University

A new analysis of a beaver anklebone fossil found in Montana suggests the evolution of semi-aquatic beavers may have occurred at least 7 million years earlier than previously thought, and happened in North America rather than Eurasia.

In the study, Ohio State University evolutionary biologist Jonathan Calede describes the find as the oldest known amphibious beaver in the world and the oldest amphibious rodent in North America. He named the newly discovered species Microtheriomys articulaquaticus.

Calede’s findings resulted from comparing measurements of the new species’ anklebone to about 340 other rodent specimens to categorize how it moved around in its environment – which indicated this animal was a swimmer. The Montana-based bone was determined to be 30 million years old – the oldest previously identified semi-aquatic beaver lived in France 23 million years ago.

"Beavers and other rodents can tell us a lot about mammalian evolution," said Calede, an assistant professor of evolution, ecology and organismal biology at Ohio State’s Marion campus.

Study finds that ocean cooling over millennia led to larger fish

Dahiana Arcila in Reykjavík, Iceland. Arcila is the recipient of a National Science Foundation CAREER award to study the evolutionary history of marine fish.
Source: University of Oklahoma

Earth’s geological history is characterized by many dynamic climate shifts that are often associated with large changes in temperature. These environmental shifts can lead to trait changes, such as body size, that can be directly observed using the fossil record.

To investigate whether temperature shifts that occurred before direct measurements were recorded, called paleoclimatology, are correlated with body size changes, several members of the University of Oklahoma’s Fish Evolution Lab decided to test their hypothesis using tetraodontiform fishes as a model group. Tetradontiform fishes are primarily tropical marine fishes, and include pufferfish, boxfishes and filefish.

The study was led by Dahiana Arcila, assistant professor of biology and assistant curator at the Sam Noble Oklahoma Museum of Natural History, with Ricardo Betancur, assistant professor of biology, along with biology graduate student Emily Troyer, and involved collaborators from the Smithsonian Institution, University of Chicago and George Washington University in the United States, as well as the University of Turin in Italy, University of Lyon in France and CSIRO Australia.

The researchers discovered that the body sizes of these fishes have grown larger over the past hundred million years in conjunction with the gradual cooling of ocean temperatures.

Scientists are relieved to discover ‘curious’ creature with no anus is not earliest human ancestor

Left to right: Saccorhytus, Saccorhytus dorsal, Saccorhytus side-on.
Credit: Philip Donoghue et al

An international team of researchers have discovered that a mysterious microscopic creature from which humans were thought to descend is part of a different family tree.

Resembling an angry Minion, the Saccorhytus is a spikey, wrinkly sack, with a large mouth surrounded by spines and holes that were interpreted as pores for gills – a primitive feature of the deuterostome group, from which our own deep ancestors emerged.

However, extensive analysis of 500-million-year-old fossils from China has shown that the holes around the mouth are bases of spines that broke away during the preservation of the fossils, finally revealing the evolutionary affinity of the microfossil Saccorhytus.

“Some of the fossils are so perfectly preserved that they look almost alive,” says Yunhuan Liu, professor in Paleobiology at Chang’an University, Xi’an, China. “Saccorhytus was a curious beast, with a mouth but no anus, and rings of complex spines around its mouth.”

The findings, published today in Nature, make important amendments to the early phylogenetic tree and the understanding of how life developed.

Uncovering the Past: Researchers Create 3D Images of Fossils

Aase mounts one of the fossils in the X-ray microscope for imaging.
Credit: Idaho National Laboratory

Idaho National Laboratory is perhaps best known for innovative research that helps shape the clean energy economies of today and tomorrow – and for good reason. But while much of the laboratory’s work is focused on building a sustainable future, INL is also doing its part to preserve the past.

INL researchers recently imaged several fossils using a powerful X-ray microscope. The 3D images will be used to create exhibits for Wyoming’s Fossil Butte National Monument and help experts gain insight into the origins of these and other relics.

The fossils, found in private quarries around Wyoming, were imaged using a technique known as X-ray microscopy. At INL, researchers typically use high-resolution X-ray microscopy to view specimens – such as samples of irradiated nuclear fuel — at a level of detail not possible with conventional microscopes. The depth and granularity afforded by this technique will help paleontologists learn a great deal about these fossils —including an unknown object resembling an insect egg case or pea pod — and the conditions under which they formed.

“You can see the limestone layers as well as submillimeter and thinner organic materials that have been compressed into waxy, pre-petroleum substances around the specimen,” said Arvid Aase, a paleontologist and the museum curator at Fossil Butte National Monument. “These incredibly detailed images will help us determine the organism’s taxonomy and reveal information about its fossilization process, such as how long it was laying on the bottom of the lake covered in microbes before getting buried by limestone.”

The fossilization process may have occurred over a period of months, though the timing still remains unknown, he added.