Entelognathus primordialis: This 419-Million-Year-Old Fish Has the World’s Oldest Known Face

Friday, September 27, 2013

A reconstruction of how the creature may have looked alive. Image via Brian Choo

The ancient fossil, just discovered in China, could upend our understanding of how all vertebrates evolved over time.

Sure, it’s not much to look at. But stare long enough, and you’ll see a jaw (jutting out towards the right), a pair of nostrils (small perforations directly above the mouth cavity) and even a tiny eye socket (just above the mouth, to the left of the nostrils, staring out sideways).

This admittedly homely fish fossil, the 419-million-year old Entelognathus primordialis, was recently discovered in China and described for the first time in an article published today in Nature. What makes it remarkable is everything that’s come after it: It’s the oldest known creature with a face, and may have given rise to virtually all the faces that have followed in the hundreds of millions of years since, including our own.

The uncommonly well-preserved, three-dimensional fossil, analyzed by a group of researchers from the Chinese Academy of Sciences, was excavated near Xiaoxiang Reservoir in Southeast China, in a layer of sediment that dates to the Silurian period, which ranged from roughly 419 to 443 million years ago. All other fish specimens from this era are jawless fish (a group of more primitive creatures that still live on today as lampreys and hagfish), so this is the first one that has what we might call a face: a mouth, nose and two eyes.

It’s difficult to conclude very much about the behavior or lifestyle of the ancient creature, but we do know that it swam in water (land animals didn’t begin to evolve until the Devonian period, which spanned 359 to 419 million years ago) and was likely a top-level predator of the early ocean ecosystem.

What has scientists so excited, though, is that the particular anatomical features of this fossil could upend our understanding of how vertebrates evolved over time. “When I first saw this, I was completely blown away,” says Matt Friedman a paleobiologist at the University of Oxford that reviewed the paper and wrote an accompanying article in Nature. “It’s the kind of fossil you might see once or twice in your lifetime, as a research scientist.”

Friedman and others find the fossil so remarkable because it combines a series of characteristics from two different groups: placoderms, an ancient class of armored fish that went extinct millions of years ago, and bony fish, a lineage that gave rise to all modern fish with jaws and bone skeletons. Previously, it was assumed that placoderms died out completely (and that the other, more recent types of fish with similar armor plating had independently re-evolved it much later), while a different, shark-like group of fish called acanthodians led to the bony fishes.

“What a fossil like this shows is that maybe that’s not the case,” Friedman says. “Because if you look at just the top of the skull and the body, it looks like a placoderm. But when you look at the side, and the front, you see it has jaws that, bone for bone, closely resemble the jaws of bony fish.”

This is significant because of what happened next: bony fish gave rise to all modern vertebrate fish, along with all amphibians, reptiles, birds and mammals, including ourselves. In other words, this fossil might mean that the placoderms didn’t go extinct, but rather evolved into the tremendous diversity of animals that live on both land and sea—and that this ancient, strange-looking face belongs to one of your oldest ancestors.

Scientists won’t immediately jump to reorganize their evolutionary family trees overnight, but the new finding will prompt a period of renewed scrutiny of the previous model. “It’s going to take a while for people to digest it and figure out what it all means,” Friedman says. “From a fossil like this, you’ve got a cascade of implications, and this is just the first paper to deal with them.”

Eventually, though, this finding could help transform our understanding of just how evolution occurred in our planet’s ancient oceans—and how the primitive creatures that swam in them eventually gave rise to the faces we see everyday.


Fossils Of Pterodactyls From 66 Million Years Ago Discovered, Show Untimely Death

Friday, March 16, 2018

Artist's impression of how the pterosaurs may have looked Photo: University of Bath

Paleontologists have just discovered 66-million-year-old fossils that belong to six new species of pterosaurs, which are prehistoric flying reptiles. Pterosaurs, aka pterodactyls, were the flying cousins of dinosaurs and are considered to be the largest breed of ancient creatures that took flight.

Soaring on wings made of skin, supported by just a single finger, these prehistoric creatures were previously thought to have been slowly going extinct, before a massive dinosaur-killing asteroid wiped out most of Earth’s animal population at the end of the Cretaceous Period. However, hundreds of newly discovered pterodactyl fossils, found at sites in northern Morocco challenge the previous theory.

The fossils reveal that seven different pterosaurs species from three different families lived in the region during the late Cretaceous Period. In other words, the ancient creatures were abundant in numbers before the asteroid impact caused their mass extinction.

“To be able to grow so large and still be able to fly, pterosaurs evolved incredibly lightweight skeletons, with the bones reduced to thin-walled, hollow tubes like the frame a carbon-fiber racing bike,” Dr. Nick Longrich from the University of Bath, and the lead author of the study, said in a statement. “But unfortunately, that means these bones are fragile, and so almost none survive as fossils.”

The rarity of pterosaur fossils from the late Cretaceous Period led many to assume that they were going extinct. However, the new study reveals that the dearth of fossils can lead to misleadingly skewed theories and that pterosaurs were actually thriving and much more diverse than previously thought.

Image shows ulna (forearm) bones from two different pterosaur species - the larger one would have had a wingspan of around 10 metres. Photo: University of Bath/ pbio.2001663

"The Moroccan fossils tell the last chapter of the pterosaurs' story - and they tell us pterosaurs dominated the skies over the land and sea, as they had for the previous 150 million years,” Dr Brian Andres, research associate at The University of Texas, and also a co-author of the study, said.

"This is a fabulous discovery of pterosaurs from Morocco - they tell us their amazing diversity while we thought them in decline,” said Moroccan paleontologist Professor Nour-Eddine Jalil from the Muséum national d'Histoire naturelle, who was not involved in this study but has worked with the authors on a previous study on fossils found in this area. "The Moroccan phosphates are an open window on a key moment in the history of the Earth, one that shortly preceded the global crisis that swept away, among others, dinosaurs and marine reptiles."

The newly discovered fossils reveal that these creatures weighed around 200 kilograms and had wingspans that ranged over two meters to up to ten meters – nearly three times bigger than the largest living bird. Researchers were also able to identify diversity in size and shape. The fossils also allowed the researchers to show that the species had significant differences in the shape of different body parts such as beak shape, neck length, and wing proportions, indicating that the newly identified species occupied distinct ecological niches.

“I believe there are many more species to find,” Dr. Longrich said.

“Exciting discoveries are being made all the time, and sometimes, just the smallest of bones can radically change our perception of the history of life on Earth,” co-author of the study, Professor David Martill from the University of Portsmouth said.

The new study has been published in the journal PLOS Biology.


Are Paleontologists Naming Too Many Species?

Friday, March 16, 2018

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

A complete new examination taking a gander at varieties in Ichthyosaurus, a typical British Jurassic ichthyosaur (maritime reptile) otherwise called ‘Ocean Dragons’, has given essential data into perceiving new fossil species.

Professor Judy Massare (SUNY College at Brockport, NY, USA) and Dean Lomax (The University of Manchester) have examined many examples of Ichthyosaurus. After their most recent research project, the pair urge caution in naming new fossil species on the basis of just a few fragmentary or isolated remains.

For their examination, Prof Massare and Lomax concentrated on one specific piece of the Ichthyosaurus skeleton, the hindfin (or back oar). The reason for existing was to assess the distinctive structures among the six-known types of Ichthyosaurus. They inspected 99 examples which could give valuable data.

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

Early in their research, they found different types of hindfin that initially appeared to represent different species. However, the more specimens they examined the more ‘variation’ they uncovered, such as differences in the size and number of bones. They determined that a single hindfin alone could not be used to distinguish among species of Ichthyosaurus, but that a particular variation was more common in certain species.

Their discoveries demonstrate that with just a couple of examples, highlights can be discovered that vary significantly starting with one example then onto the next and in this way show up as though there are a few animal categories. Though, as a general rule, with a significantly bigger example measure the holes in the ‘one of a kind’ varieties are filled in, demonstrating that distinctions are essentially the aftereffect of individual variation and an absence of the full picture.

Prof Massare said: “We described a few hindfins, which might have been called a new species if they were found in isolation. Instead, we had enough specimens to determine that it was just an extreme variation of a common form.”

Scientists can be categorized as one of two camps with regards to naming species, ‘lumpers’ and ‘splitters’. The previous ‘protuberance’ gatherings of comparable examples together, though the last pick to part up examples and recognize new species. Be that as it may, in this new examination, if the group picked to part up the examples in view of the variety discovered, it would propose an immense number of animal varieties.

“On the off chance that we thought about the variety as interesting, it would mean we would name around 30 new species. This would be like what was done in the Nineteenth Century when any new fossil find, from another area or skyline, was named as another species on the off chance that it varied marginally from already known examples.

“As bunches of new fossil species are named each year, at times, for example, with fragmentary or restricted remains, the choice to name another species ought to be viewed as deliberately.”

The new study has been published today in the scientific journal, Geological Magazine.


New research solves the 60-year-old paleontological mystery of a 'phantom' dicynodont

Friday, March 16, 2018

Skeleton of the dicynodont Placerias, a close relative of the newly-discovered Pentasaurus, with dicynodont trackways (Pentasauropus). Credit: Christian Kammerer  Read more at:

A new study has re-discovered fossil collections from a 19th century hermit that validate 'phantom' fossil footprints collected in the 1950s showing dicynodonts coexisting with dinosaurs.

Before the dinosaurs, around 260 million years ago, a group of early mammal relatives called dicynodonts were the most abundant vertebrate land animals. These bizarre plant-eaters with tusks and turtle-like beaks were thought to have gone extinct by the Late Triassic Period, 210 million years ago, when dinosaurs first started to proliferate. However, in the 1950s, suspiciously dicynodont-like footprints were found alongside dinosaur prints in southern Africa, suggesting the presence of a late-surviving phantom dicynodont unknown in the skeletal record. These "phantom" prints were so out-of-place that they were disregarded as evidence for dicynodont survival by paleontologists. A new study has re-discovered fossil collections from a 19th century hermit that validate these "phantom" prints and show that dicynodonts coexisted with early plant-eating . While this research enhances our knowledge of ancient ecosystems, it also emphasizes the often-overlooked importance of trace fossils, like footprints, and the work of amateur scientists.

"Although we tend to think of paleontological discoveries coming from new field work, many of our most important conclusions come from specimens already in museums," says Dr. Christian Kammerer, Research Curator of Paleontology at the North Carolina Museum of Natural Sciences and author of the new study.

The re-discovered fossils that solved this mystery were originally collected in South Africa in the 1870s by Alfred "Gogga" Brown. Brown was an amateur paleontologist and hermit who spent years trying, with little success, to interest European researchers in his discoveries. Brown had shipped these specimens to the Natural History Museum in Vienna in 1876, where they were deposited in the museum's collection but never described.

"I knew the Brown collections in Vienna were largely unstudied, but there was general agreement that his Late Triassic collections were made up only of dinosaur fossils. To my great surprise, I immediately noticed clear dicynodont jaw and arm bones among these supposed 'dinosaur' fossils," says Kammerer. "As I went through this collection I found more and more bones matching a dicynodont instead of a dinosaur, representing parts of the skull, limbs, and spinal column." This was exciting—despite over a century of extensive collection, no  of a dicynodont had ever been recognized in the Late Triassic of South Africa.

Before this point, the only evidence of dicynodonts in the southern African Late Triassic was from questionable footprints: a short-toed, five-fingered track named Pentasauropus incredibilis (meaning the "incredible five-toed lizard foot"). In recognition of the importance of these tracks for suggesting the existence of Late Triassic dicynodonts and the contributions of "Gogga" Brown in collecting the actual fossil bones, the re-discovered and newly described dicynodont has been named Pentasaurus goggai ("Gogga's five-[toed] lizard").

"The case of Pentasaurus illustrates the importance of various underappreciated sources of data in understanding prehistory," says Kammerer. "You have the contributions of amateur researchers like 'Gogga' Brown, who was largely ignored in his 19th century heyday, the evidence from footprints, which some paleontologists disbelieved because they conflicted with the skeletal evidence, and of course the importance of well-curated museum collections that provide scientists today an opportunity to study specimens collected 140 years ago."

The paper, "The first skeletal evidence of a dicynodont from the lower Elliot Formation of South Africa," is published in the journal Palaeontologia Africana.

Provided by: North Carolina Museum of Natural Sciences


Study Sheds Light on Different Ways Dinosaurs Hatched Eggs

Sunday, March 18, 2018

This artist's image shows a hadrosaurus, a dinosaur that is thought to have used heat from microbial decay to warm its eggs. (Image by Masato Hattori, courtesy of the Nagoya University Museum)

Some dinosaurs used heat of the sunlight or microbial decay to warm their eggs, while others brooded, a study by a team including a researcher from Nagoya University suggests.

The study by the team including Japanese researcher Kohei Tanaka was published online in the British journal Scientific Reports. While the fossils of dinosaur eggs and nests have been discovered across the globe, it was not clear how dinosaurs warmed their eggs.

To understand nesting habits, the team researched species including alligators and birds which take advantage of surrounding heat to warm their eggs, as they are similar to dinosaurs. They found that the nesters mainly used microbial decay to warm their eggs when the nesting material consisted of dirt or plants, and sunlight in sandy nesting locations. The researchers used this knowledge to analyze 192 fossilized dinosaur nests.

The nests of some sauropods -- giant herbivorous dinosaurs having a small head and a long neck -- were found in coarse-grained sediment such as sandstone. This led researchers to presume that these dinosaurs used solar radiation or geothermal heat to incubate their eggs.

For the hadrosaurus, a herbivorous dinosaur whose face is like the platypus, researchers concluded it was possible microbial decay was used for incubation because hadrosaurus nests were mainly discovered in fine-grained deposits such as mudstone.

The scientists also analyzed nests of troodontids, small carnivorous dinosaurs similar to birds, including eggs. The fossils were discovered in both fine-grained and coarse-grained deposits, indicating that the eggs were hatched in any type of environment. This supported the theory that these dinosaurs brooded.

Tanaka, who works as a special researcher at Nagoya University Museum, commented, "I want to utilize differences in the ways of warming eggs to shed light on the habitats of dinosaurs."


Kerygmachela kierkegaardi: 520-Million-Year-Old Predator’s Fossilized Brains Discovered

Thursday, March 15, 2018

Image Source: Rebecca Gelernterk, Near Bird Studios

Scientists have peered into the brain of a prehistoric creature that lived around 520 million years ago. Fifteen fossils of the ancient predator were recently discovered in Greenland, which had fortunately escaped the ravages of time and elements.

This allowed the creature’s nervous tissue to be fossilized, providing researchers with new insights into panarthropods' evolutionary developments. Panarthropods are an animal group that include creatures such as tardigrades or water bears, velvet worms and arthropods, such as insects.

“The findings shed light on the ancestral condition of the panarthropod brain and the origin of complex arthropod compound eyes. The new material, furthermore, provides novel information on the overall anatomy of Kerygmachela,” the researchers wrote in the new study, published in the journal Nature Communications.

The newly discovered fossils belonged to a now-extinct species called Kerygmachela kierkegaardi. The prehistoric creature swam across the Earth’s oceans during the Cambrian explosion — an era that saw the emergence of incredible and rapid diversity among life forms over a short period of time.

The ancient creature measures between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body. Photo: Tae-Yoon Park/Nature Communications

The ancient creature measured between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body. The predator also sported a round head and an elongated tail spine. United Kingdom-based paleontologist Jakob Vinther, who led the study along with Tae-Yoon Park of the Korea Polar Research Institute, told National Geographic the creature’s forward-facing appendages grabbed onto prey, “making lives miserable for other animals.”

The new study challenges previous theories that claimed the common ancestor of all panarthropods had complex three-part brain. Instead, the researchers argue the new evidence indicated the common ancestor of panarthropods, as well as invertebrate panarthropods and vertebrates, did not have complex brains.

Researchers believe despite its simple brain, the Kerygmachela’s eyes were likely complex enough to form images. The ancient predator’s eyes likely mirror the smaller and much simpler eyes of modern-day tardigrades and velvet worms, Science reported.

However, some scientists appear to be unconvinced of the new details.

“If they’re going to say that the brain of Kerygmachela is like that of a tardigrade, you have to be really, really careful,” Nicholas Strausfeld told National Geographic. “Because it might not be.”

“The discovery of the simple unipartite brain in stem-group euarthropods corroborates the ancestral simplicity of the panarthropod brain, and also suggests that the complex neural concentrations, such as tripartite brains in euarthropods and chordates, are the result of convergent adaptations,” the researchers concluded.


Extinct Bird with Dinosaur-Like Claw May Soon Be Resurrected

Monday, March 12, 2018

Preserved Megalapteryx (moa) foot, Natural History Museum (CC by SA 2.0)

A clawed, flightless bird that went extinct in New Zealand in the late 13th century might be brought back to life, claim scientists at Harvard University.

Nearly three decades ago, archaeologists exploring a cave system on Mount Owen in New Zealand discovered a dinosaur-like claw with flesh and scaly skin. After testing it proved to the a 3,300-year-old mummified remains of an upland moa (Megalapteryx didinus). A DNA analysis published in the  Proceedings of the National Academy of Sciences established that there were at least “ten species of moa which appeared around 18.5 million years ago” but they were all wiped from existence in what scientists call “the most rapid, human-facilitated megafauna extinction documented to date.”

Sir Richard Owen standing next to a moa skeleton and holding the first bone fragment belonging to a moa ever found. (public domain)

Using DNA recovered from the toe, Harvard scientists have now mapped and compiled the first almost complete genome of a “little bush moa,” moving closer to the possibility that extinct genomes will soon become “de-extinct.” The whole idea of bringing “vanished species back to life by slipping the genome into the egg of a living species,” has been regarded by some reviewers as equal to the dark fictional works of Dr Frankenstein, while to others, it has been described in a lighter light as being ‘Jurassic Park’-like,” according to an article on

Left: Illustration of a Moa. Right: Preserved footprint of a Moa (public domain)

Let’s not enter the moral debate, for that is wholly subjective, and look closer at the processes and innovations of Stewart Brand, the co-founder of the nonprofit conservation group Revive and Restore. Aiming to “resurrect vanished species” Brand’s team’s work on the DNA of the little bush moa was recently published in a non-peer-reviewed paper and Brand told reporters “De-extinction probability increases with every improvement in ancient DNA analysis.” The DNA was reconstructed from the sample taken from the creature’s toe but scientists know that “a lot of genetic restructuring is required before the creature can be reborn.” And with the prospects of a creature which stands as high as a teenager, scientists predict they might have to use a "6-inch long, 1-pound emu egg to incubate the moa”.

Stewart Brand had already mapped the passenger pigeon genome and the woolly mammoth, and speaking of this latest project to reporters at, Morten Erik Allentoft of the Natural History Museum of Denmark, an expert on moa DNA said it is “a significant step forward.” As well as the woolly mammoth and passenger pigeon, among the “nearly complete” extinct genomes, scientists have almost completed two of our human cousins, Neanderthals and Denisovans, the dodo, the Tasmanian tiger and the great auk, which dyed out in the North Atlantic in the mid-19th century.

Scientists have almost completed the mapping of the Tasmanian Tiger genome, another extinct species that may soon be revived (public domain).

According to Harvard’s Alison Cloutier, the little bush moa team tried to match “900 million nucleotides, scattered across millions of DNA pieces, and tried to match them to specific locations on the genome of the emu, a close relative of all nine moa species.” Bird genomes, including the eight other extinct moa species, “have similar genes for particular traits tend to be on the same chromosome and arranged relative to other genes in a similar way,” according to the article.

Similarly, according to Harvard’s George Church, who leads The Mammoth Project, “elephant chromosomes were studied to better know how mammoth DNA might be organized.” Scientists believe that herpes infections killed off the mammoth and if it was made ‘de-extinct’, its immune system could be enhanced to resist this virus. You might be asking, like I did, wasn’t all this DNA and genome mapping sorted out “before” the 1996 birth of Dolly the Sheep at the Roslin institute in Scotland?

“Kind of” is the answer, the problem is, putting DNA into an egg is infinitely more difficult than fertilizing mammals. The cloning method applied to make Dolly the Sheep is fine for a mammalian eggs, “but that doesn’t work in birds — “at least so far,” Brand told reporters.

There is no doubt the final parts in the cloning puzzle will be solved, and given enough time, maybe not in our lifetime, a country or a private enterprise will inevitably work out how to clone us.


Paleontologists Find ‘Bubbles of Oxygen’ in 1.6-Billion-Year-Old Stromatolites

Thursday, March 8, 2018

Fossilized bubbles and cyanobacterial fabric from 1.6 billion-year-old phosphatized microbial mats of the Chitrakoot Formation in central India. Image credit: Stefan Bengtson.

An international research team led by Swedish Museum of Natural History scientists has found that stromatolites (solid, laminar structures of biological origin) from the 1.6-billion-year-old Chitrakoot Formation in India contain abundant fossilized oxygen bubbles.

“Microbes were the first life forms on Earth,” said lead author Dr. Therese Sallstedt, from the Department of Paleobiology at the Swedish Museum of Natural History, and colleagues.

“They turned our planet into a tolerable environment for plants and animals and thus their activity paved the way for life as we know it today.”

“Some of these early microbes were cyanobacteria that thrived in early shallow waters. They produced oxygen by photosynthesis, and sometimes the oxygen got trapped as bubbles within sticky microbial mats.”

Dr. Sallstedt’s team studied fossilized sediments from central India and found round spheres in the microbial mats.

Fossilized bubbles and cyanobacterial fabric from 1.6 billion-year-old phosphatized microbial mats of the Chitrakoot Formation. Image credit: Stefan Bengtson.

Dr. Sallstedt’s team studied fossilized sediments from central India and found round spheres in the microbial mats.

These ‘bubbles’ were created by tiny microbes in what was once a shallow sea somewhere on the young Earth, according to the researchers.

“We interpret them as oxygen bubbles created in cyanobacterial biomats in shallow waters 1.6 billion years ago,” Dr. Sallstedt said.

SEM micrograph of the fossilized bubbles. Image credit: Stefan Bengtson.

“Cyanobacteria changed the face of the Earth irreversibly since they were responsible for oxygenating the atmosphere. Simultaneously they constructed stromatolites, which still exist on Earth today,” the paleontologists said.

“We now think that cyanobacteria played a larger role than previously believed in creating phosphorites in shallow waters, thereby allowing today’s scientists a unique window into ancient ecosystems.”

The team’s findings were published in the March 2018 issue of the journal Geobiology.


T. Sallstedt et al. 2018. Evidence of oxygenic phototrophy in ancient phosphatic stromatolites from the Paleoproterozoic Vindhyan and Aravalli Supergroups, India. Geobiology 16 (2): 139-159; doi: 10.1111/gbi.12274


Flightless Bird Extinct for More Than 700 Years Can be Brought Back to Life, Say Scientists

Wednesday, February 28, 2018

Museum host shows Singapore's Prime Minister Lee Hsien Loong a giant Moa bird during a visit to Te Papa Museum in Wellington. [Representational Image]

The little bush moa inhabited parts of New Zealand and went extinct in the late 13th century as a result of overhunting.

Scientists are a step closer to bringing back a species of flightless bird that has been extinct for almost 700 years. The little bush moa that inhabited parts of New Zealand went abruptly extinct as a result of overhunting in the late 13th century.

A team of researchers from Harvard University has assembled a nearly-complete genome of the extinct moa by extracting ancient DNA from the toe bone of a moa specimen held at the Royal Ontario Museum in Toronto, Canada.

The scientists now believe that they are closer to the goal of "de-extinction" — the vanished species can be brought back to life by slipping the genome into the egg of a living species, Statnews reported.

"High throughput sequencing has revolutionized the field of ancient DNA (aDNA) by facilitating recovery of nuclear DNA for greater inference of evolutionary processes of extinct species than is possible from mitochondrial DNA alone," according to the study.

Credit: J. Erxleben, Transactions of the Zoological Society of London v. 11, Wikimedia

The little bush moa was a part of the palaeognathae clade of birds and birds, and those like the kiwi, ostrich, and emu were considered its cousins. There were nine species of the moa but all of them are extinct now.

They roamed in the forests of the North and South Islands of New Zealand before they became extinct, the NZ Herald said. They were on an average four feet tall and weighed about 66 pounds.

Experts believe that the Harvard researchers' work could make it easier to bring back the long-lost species from extinction.

"The fact that they could get a genome from a little bush moa toe is a big deal since now we might be able to use their data to do other extinct bird species," Ben Novak, lead scientist at non-profit conservation group Revive and Restore, told Statnews.

"De-extinction could be useful for inspiring new science and could be beneficial for conservation if we ensure it doesn't reduce existing conservation resources," University of Queensland scientist Hugh Possingham said in a statement.

"However, in general, it is best if we focus on the many species that need our help now," he added.


Fossil Turtle Species, 5.5 Million Years Old, Sheds Light on Invasive Modern Relatives

Wednesday, February 28, 2018

Though initially found in pieces, Gray Fossil Site preparator Shawn Haugrud was able to glue the shell of this species back together, enabling Penn's Steven Jasinski to complete an analysis of the turle. Jasinski named the species in Haugrud's honor. Credit: Image courtesy of University of Pennsylvania

A University of Pennsylvania paleontologist has described a 5.5 million-year-old fossil species of turtle from eastern Tennessee. It represents a new species of the genus Trachemys, commonly known as sliders, which are frequently kept as pets today.

Steven Jasinski, author of the new study, is a doctoral student at the University of Pennsylvania and acting curator of paleontology and geology at the State Museum of Pennsylvania. He is completing his Ph.D. at Penn under Peter Dodson, a professor of paleontology in the Department of Earth and Environmental Science in the School of Arts and Sciences and a professor of anatomy in the School of Veterinary Medicine.

The study investigated a fossil turtle found around the Miocene - Pliocene boundary in the Gray Fossil Site, an area rich with fossils in eastern Tennessee near East Tennessee State University, where Jasinski completed his master's degree. The site represents an ancient sinkhole surrounded by a forest from which dozens of fossil animal species have been characterized, including new species of red panda, Eurasian badger, kinosternid turtle, and colubrid snake.

Thorough examination of the dozens of turtle fossils from the site revealed important differences between this turtle and other known fossil and living species. Jasinski named the fossil turtle Trachemys haugrudi, after Shawn Haugrud, the lab and field manager and lead preparer at the Gray Fossil Site.

"Shawn has spent an incredible number of hours working on these specimens," Jasinski said. "He cleaned and prepared the fossils and was able to essentially glue this turtle back to life, giving me numerous nearly complete turtle shells to use in this research. Without all that time and effort, I wouldn't have been able to determine nearly as much about this turtle as I did.

"Shawn also didn't do this work alone, as numerous other people including volunteers worked on these fossils and got them prepared so that I could complete my research. They really did all the hard work, and I was then able to determine why it was new and what its implications are" he said.

Turtles are best known for their shells, and indeed it is this feature of their anatomy that is commonly found as fossils. Yet the fossil shells are typically found in broken pieces. Often gaps or holes remain, or only single small pieces are found, and the whole must be inferred from other information, including other fossil and living creatures.

"It is extremely rare to get more complete fossils," Jasinski said, "but Trachemys haugrudi, commonly called Haugrud's slider turtle, provides me with dozens of shells, and several are nearly complete."

Haugrud's slider turtle was a fairly small turtle, not more than approximately 10 inches (25 cm) in total shell length, smaller than the modern-day red-eared slider turtle, Trachemys scripta elegans. Red-eared slider turtles are commonly purchased as pets, though they can grow large, and some owners release them into the wild. As a result, though native to the southeastern United States, red-eared sliders have become one of the most invasive animal species in the world today, found on every continent except Antarctica.

"People tend to see all turtles as similar and release them into whatever pond or river is close by when they no longer want to care for them," Jasinski said. "Once released, however, they often outcompete native species. It is a problem that scientists are still dealing with."

As part of the study, Jasinski sought to determine where Trachemys haugrudi was positioned in the evolution of similar turtles both within the genus and in related genera. He performed a phylogenetic analysis, a method that compares shapes and features of different species to determine how similar or dissimilar and therefore how closely related they may be. He found Haugrud's to be most closely related to a group of fossil Trachemys turtles from Florida and next most closely related to a distinct group of fossil Trachemys from the midwestern U.S. Together, these fossil Trachemys form a closely related group situated within other still-living species of Trachemys.

Today, distinct, closely-related groups of Trachemys species dwell in Mexico, Central and South America, and the Caribbean. Jasinski's investigation, along with other information from previous studies, indicates that one group evolved in Mexico and Central and South America and evolved into different species within this geographic area, and another group evolved separately in the Caribbean.

Species from the U.S., including the red-eared slider turtle, are found near the base of their "branch" of the Trachemys family tree; their fossil ancestors are still waiting to be discovered. The fossil Trachemys species in Jasinski's analysis are on a distinct part of the Trachemys tree, and current understanding suggests that they did not give rise to the modern species living today.

The findings imply that there was once much greater diversity in Trachemys turtles than exists today. It seems that many of the ancient slider species died out without leaving any direct descendents, perhaps because they lacked the ability to adapt to different environments.

"While Trachemys turtle species are considered plastic, implying they can adapt to and live in many environments, this adaptive lifestyle may be a relatively newer characteristic of these turtles," Jasinski said. "More fossils are needed to better understand if this aspect of their evolution is a recent addition."

To get a handle on invasive turtles, understanding more about their ancient relatives could only be helpful, Jasinski said.

"Trachemys haugrudi helps provide more information on Trachemys and begins to offer us insights into the evolution of an animal that has become a problematic invader in many areas of the world," he said. "Understanding how something evolved into its present form may help us understand why an animal is so adaptive and good at invading new areas and outcompeting native species. If we can see that Trachemys today are especially adaptive because evolution has allowed them to become more generalized through time, we can use that information to determine where they may invade, what species they may outcompete and what we can do to counteract those invasions or help native species compete against them."

Jasinski is undertaking further study into the fossil species of not only Trachemys but other turtles within the family Emydidae, which includes Trachemys. He hopes that further data and fossils will help shed light on other turtle species and provide a clearer understanding of the evolution of this group of mainly New World turtles.

The study was supported by the National Science Foundation (Grant 0958985 to Steven Wallace and the Gray Fossil Site), Office of Research and Sponsored Programs at East Tennessee State University, Don Sundquist Center of Excellence in Paleontology, State Museum of Pennsylvania, and Department of Earth and Environmental Science at the University of Pennsylvania.

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

Journal Reference:

  1. Steven E. Jasinski. A new slider turtle (Testudines: Emydidae: Deirochelyinae: Trachemys) from the late Hemphillian (late Miocene/early Pliocene) of eastern Tennessee and the evolution of the deirochelyinesPeerJ, 2018; 6: e4338 DOI: 10.7717/peerj.4338