First egg from Antarctica is big and might belong to an extinct sea lizard

Date: June 17, 2020

Source: University of Texas at Austin

In 2011, Chilean scientists discovered a mysterious fossil in Antarctica that looked like a deflated football. For nearly a decade, the specimen sat unlabeled and unstudied in the collections of Chile's National Museum of Natural History, with scientists identifying it only by its sci-fi movie-inspired nickname -- "The Thing."

An analysis led by researchers at The University of Texas at Austin has found that the fossil is a giant, soft-shell egg from about 66 million years ago. Measuring in at more than 11 by 7 inches, the egg is the largest soft-shell egg ever discovered and the second-largest egg of any known animal.

The specimen is the first fossil egg found in Antarctica and pushes the limits of how big scientists thought soft-shell eggs could grow. Aside from its astounding size, the fossil is significant because scientists think it was laid by an extinct, giant marine reptile, such as a mosasaur -- a discovery that challenges the prevailing thought that such creatures did not lay eggs.

"It is from an animal the size of a large dinosaur, but it is completely unlike a dinosaur egg," said lead author Lucas Legendre, a postdoctoral researcher at UT Austin's Jackson School of Geosciences. "It is most similar to the eggs of lizards and snakes, but it is from a truly giant relative of these animals."

A study describing the fossil egg was published in Nature on June 17.

Co-author David Rubilar-Rogers of Chile's National Museum of Natural History was one of the scientists who discovered the fossil in 2011. He showed it to every geologist who came to the museum, hoping somebody had an idea, but he didn't find anyone until Julia Clarke, a professor in the Jackson School's Department of Geological Sciences, visited in 2018.

"I showed it to her and, after a few minutes, Julia told me it could be a deflated egg!" Rubilar-Rogers said.

Using a suite of microscopes to study samples, Legendre found several layers of membrane that confirmed that the fossil was indeed an egg. The structure is very similar to transparent, quick-hatching eggs laid by some snakes and lizards today, he said. However, because the fossil egg is hatched and contains no skeleton, Legendre had to use other means to zero in on the type of reptile that laid it.

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Arctic Edmontosaurus lives again: A new look at the 'caribou of the Cretaceous'

Date: May 6, 2020

Source: Perot Museum of Nature and Science

A new study by an international team from the Perot Museum of Nature and Science in Dallas and Hokkaido University and Okayama University of Science in Japan further explores the proliferation of the most commonly occurring duck-billed dinosaur of the ancient Arctic as the genus Edmontosaurus. The findings also reinforce that the hadrosaurs -- known as the "caribou of the Cretaceous" -- had a huge geographical distribution of approximately 60 degrees of latitude, spanning the North American West from Alaska to Colorado.

The scientific paper describing the find -- titled "Re-examination of the cranial osteology of the Arctic Alaskan hadrosaurine with implications for its taxonomic status" -- has been posted in PLOS ONE, an international, peer-reviewed, open-access online publication featuring reports on primary research from all scientific disciplines. The authors of the report are Ryuji Takasaki of Okayama University of Science in Japan; Anthony R. Fiorillo, Ph.D. and Ronald S. Tykoski, Ph.D. of the Perot Museum of Nature and Science in Dallas, Texas; and Yoshitsugu Kobayashi, Ph.D. of Hokkaido University Museum in Japan.

"Recent studies have identified new species of hadrosaurs in Alaska, but our research shows that these Arctic hadrosaurs actually belong to the genus Edmontosaurus, an abundant and previously recognized genus of duck-billed dinosaur known from Alberta south to Colorado," said Takasaki.

The report states that anatomical comparisons and phylogenetic analyses clearly demonstrate that attribution of the Alaskan hadrosaurines to a unique genus Ugrunaaluk is inappropriate, and they are now considered as a junior synonym of Edmontosaurus, a hadrosaurines genus previously known from lower latitude North America roughly in between northern Colorado (N40?) to southern Alberta (N53?).

The fossils used for this study were found primarily in the Liscomb Bonebed, Prince Creek Formation of the North Slope of Alaska, the location of the first dinosaur fossils discovered in the Arctic.

The team's research also show that the plant-eating hadrosaurs were taking over parts of North America during the Cretaceous, suggesting that Edmontosaurus was likely an ecological generalist.

"In other words, Edmontosaurus was a highly successful dinosaur that could adapt to a wide variety of environmental conditions," said Fiorillo. "It's not unrealistic to compare them to generalized animals today -- such as mountain sheep, wolves and cougars in terms of their range and numbers -- that also roam greater geographic distributions."

Members of this team also found ties to Kamuysaurus japonicus, a new genus species they discovered near Hokkaido, Japan, and named in 2019.

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Ancestor of all animals identified in Australian fossils

A wormlike creature that lived more than 555 million years ago is the earliest bilaterian

Date: March 23, 2020

Source: University of California - Riverside

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.

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Rare lizard fossil preserved in amber - via Herp Digest

Date: February 27, 2020

Source: University of Bonn

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.

Story Source:

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

Journal Reference:

1. H. Jonas Barthel, Denis Fougerouse, Thorsten Geisler, Jes Rust. Fluoridation of a lizard bone embedded in Dominican amber suggests open-system behavior. PLOS ONE, 2020; 15 (2): e0228843 DOI: 10.1371/journal.pone.0228843

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Palaeontologists Identify New Prehistoric Amphibian: A Salamander Named Egoria - via Herp Digest

TOPICS:Amphibians Evolution Paleontology By ST. PETERSBURG STATE UNIVERSITY FEBRUARY 21, 2020

A group of Russian and German paleontologists have described a previously unknown genus and species of prehistoric salamanders. The new amphibian is named Egoria malashichevi — in honor of Yegor Malashichev a talented scientist and associate professor of the Department of Vertebrate Zoology at St Petersburg University, who passed away at the end of 2018. Credit: Vadim Glinskiy 

They lived on the Earth about 166-168 million years ago, in the Middle Jurassic. The paleontologists found the remains of the ancient amphibian at the Berezovsky quarry, a fossil locality in the Krasnoyarsk Krai near the town of Sharypovo. Fossils of ancient fish, various reptiles, mammals, herbivorous and predatory dinosaurs have been previously found there. The research materials were collected on field expeditions in the mid-2010s. In these expeditions the scientists from St Petersburg University worked alongside experts from the University of Bonn (Germany), the Tomsk State University, the Zoological Institute of the Russian Academy of Sciences, and the Sharypovo Museum of Local History and Nature. 

Four vertebrate fossils enabled the scientists to declare the finding of a new genus and species. These were: three trunk vertebrae and the atlas — the first and, in the case of the salamander, the only cervical vertebra. Since the atlas is a highly specialized vertebra, providing for attachment and rotation movements of the skull, it has a rather complex structure, the scientists explain. It is therefore most suitable for describing a new species as it provides much information for analysis. The amphibian proved to have belonged to the geologically oldest stem salamanders. 

It was not the first time that remains of ancient salamanders had been found at the Berezovsky quarry. One of them — a basal stem salamander Urupia monstrosa, named after the nearby Uryup River — was about 50-60 centimeters long. Another one — Kiyatriton krasnolutskii — was named after a local historian Sergei Krasnolutskii, the discoverer of the fossil locality Berezovsky quarry. By contrast, this one was quite small in size (about 10-15 centimeters) and looked more like modern Hynobiidae. The newly discovered salamander, judging by the size of the vertebrae, was of medium length (about 20 centimeters). 

‘Salamanders first appear in the fossil records in the Middle Jurassic, including representatives of both the present-day salamander families and the most primitive ones,’ said Pavel Skutschas, associate professor of St Petersburg University, doctor of biology, expert in Mesozoic vertebrates. ‘When they had just appeared, salamanders made efforts to occupy different ecological niches. Thus, the stem salamanders filled the niche of large water bodies; while those close to the present-day salamanders found their niche in small water bodies. As for the newly discovered salamander, it occupied a middle position, although morphologically, it is closer to the primitive.’ 

The scientists not only described the external characteristics of the specimens, but were able to look inside the fossils. In this, they were assisted by the experts from the ‘Centre of X-ray diffraction studies’ at the Research Park of St Petersburg University, where the specimens were scanned on up-to-date microtomography scanners. Based on the obtained data, the paleontologists created 3D reconstructions of the vertebrae and described their internal structure. As expected, it proved to be very similar to that of the large stem salamanders. The ancient amphibian received the name Egoria malashichevi — in honor of Yegor Malashichev, associate professor of the Department of Vertebrate Zoology at St Petersburg University, who, among other things, studied the morphology of caudate amphibians. ‘Yegor Malashichev was a wonderful person and a very talented scientist. 

He supported aspiring palaeontologists and did everything to help them to stay in scientific research,’ remarked Pavel Skutschas. Additionally, Malashichev studied the phenomenon of lateralization (body asymmetries associated with the functioning of the nervous system), as well as other asymmetries in motor performance and visual perception. Yegor Malashichev’s professional career was almost exclusively connected with St Petersburg University. In 1996, he graduated from the Faculty of Biology and Soil Science. In 2000, he began to teach there, and in 2003, he defended his dissertation and was awarded a PhD in biology. Sadly, in late 2018, he passed away unexpectedly. The next step for the paleontologists is to compare the bones of the ‘Berezovsky’ salamanders with the fossils from Great Britain: the ‘Kirtlington’ salamanders which were found at the Kirtlington quarry in Oxfordshire. The Siberian and British faunas of the mid-Jurassic time were very similar. Besides, the paleontologists are aware of similar amphibians that lived in the territory of present-day England. 

‘They may be representatives of the same genera. However, to ascertain this, a detailed comparison of the palaeontological collections is required. In the coming spring, our colleagues from England will come to St Petersburg to study our research materials. We may discover that Urupia and Egoria used to have a very wide habitat, extending across Europe and Asia,’ mused Pavel Skutschas. 

Reference: “A new small-sized stem salamander from the Middle Jurassic of Western Siberia, Russia” by Pavel Skutschas, Veniamin Kolchanov, Sergey Krasnolutskii, Alexander Averianov, Rico Schellhorn, Julia Schultz and Thomas Martin, 19 February 2020, PLOS ONE. DOI: 10.1371/journal.pone.0228610A

This may be the biggest turtle that ever lived

By Laura Geggel - Associate Editor 5 days ago

This jaw-droppingly huge specimen is the largest known complete turtle shell on Earth.

An 8-million-year-old turtle shell unearthed in Venezuela measures nearly 8 feet (2.4 meters) long, making it the largest complete turtle shell known to science, a new study reported. 

This shell belonged to an extinct beast called Stupendemys geographicus, which lived in northern South America during the Miocene epoch, which lasted from 12 million to 5 million years ago. 

S. geographicus weighed an estimated 2,500 lbs. (1,145 kilograms), almost 100 times the size of its closest living relative, the Amazon river turtle (Peltocephalus dumerilianus), and twice the size of the largest living turtle, the marine leatherback (Dermochelys coriacea), the researchers wrote in the study.

Its impressive shell makes this ancient creature "one of the largest, if not the largest turtle that ever existed," study senior researcher Marcelo Sánchez-Villagra, the director of the Paleontological Institute and Museum at the University of Zurich, said in a statement. 

The species likely achieved its colossal size thanks to the warm wetlands and lakes in its habitat, Sánchez noted.

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Is the Bible right? Newly discovered fossils show snakes had legs - via Herp Digest

A new study published in Science Advances on Thursday has shed light on the life of ancient legged snakes.

By ROSSELLA TERCATIN   NOVEMBER 24, 2019

The skull of a snake nearly 100 million years old that belonged to the extinct group Najash, which retained hind legs.

(photo credit: FERNANDO GARBEROGLIO)

The Biblical story of the forbidden fruit – which discusses how the snake persuaded Eve to taste it, and  how she and Adam, who also ate from it, were subsequently banned from the Garden of Eden by God – is probably one of the most well-known narratives in the history of humankind.

As described in Genesis, the snake also received divine punishment. “You will crawl on your belly and eat dirt all the days of your life,” God tells the serpent, implying that before the event, the animal had legs, similar to many others.

Now, a new study published in Science Advances on Thursday has shed light on the life of snakes' legged ancestors. 

Several fossils of an extinct snake group named "Najash" dating back to 100 million years ago were recently uncovered in Patagonia, Argentina.

The group is named after the word nachash that both in biblical and modern Hebrew indicate the snake.

As reported by the New York Times, the fossils, which include several skulls, seem to suggest that snakes might have lost their front legs millions of years earlier than their hind legs.

“That skull is now the most complete Mesozoic snake skull known and preserves key data on ancient snake anatomy,” research leader Fernando Garberoglio told The New York Times.

The notion that snakes started off as four-legged animals has been accepted by scientists for several years, although, according to the Times, no fossils have been found to corroborate the theory.

Prior to the Patagonia extraordinary discovery, researchers thought that a two-legged phase was at most transitional between four legs and a limbless body. Now it appears that the transition might have lasted dozens of millions of years.

“‘Snakeness’ is really old, and that’s probably why we don’t have any living representatives of four-legged snakes like we do all of the other lizards,” Michael Caldwell, a vertebrate paleontologist at the University of Alberta and a co-author of the study, explained to the Times.

“Snakes probably were one of the first lizard groups to start experimenting with limblessness, but what’s really intriguing is that they were also very clearly showing the characteristics of their skulls, which are their specialization,” he added.