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Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

Stretchy slabs found in the deep Earth

November 27th, 2015

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A new study suggests that the common belief that the Earth’s rigid tectonic plates stay strong when they slide under another plate, known as subduction, may not be universal.

Typically during subduction, plates slide down at a constant rate into the warmer, less-dense mantle at a fairly steep angle. However, in a process called flat-slab subduction, the lower plate moves almost horizontally underneath the upper plate.

The research, published in the journal Nature Geoscience, found that the Earth’s largest flat slab, located beneath Peru, where the oceanic Nazca Plate is being subducted under the continental South American Plate, may be relatively weak and deforms easily.

By studying the speed at which seismic waves travel in different directions through the same material, a phenomenon called seismic anisotropy, the researchers found that interior of the Nazca plate had been deformed during subduction.

3D image of the Nazca slab subduction.
Credit: Image courtesy of University of Southampton

Lead author of the study, Dr Caroline Eakin, Research Fellow in Ocean and Earth Science at the University of Southampton, said: “The process of consuming old seafloor at subduction zones, where great slabs of oceanic material are swallowed up, drives circulation in the Earth’s interior and keeps the planet going strong. One of the most crucial but least known aspects of this process is the strength and behavior of oceanic slabs once they sink below the Earth’s surface. Our findings provide some of the first direct evidence that subducted slabs are not only weaker and softer than conventionally envisioned, but also that we can peer inside the slab and directly witness their behavior as they sink.”

When oceanic plates form at mid-ocean ridges, their movement away from the ridge causes olivine (the most abundant mineral in the Earth’s interior) to align with the direction of plate growth. This olivine structure is then ‘frozen’ into the oceanic plate as it travels across the Earth’s surface. The olivine fabric causes the seismic waves to travel at different speeds in different directions, depending on whether or not they are going ‘with the grain’ or ‘against the grain’.

The scientists measured seismic waves at 15 local seismic stations over two and a half years, from 2010 to 2013, and seven further stations located on different continents. They found that the original olivine structure within the slab had vanished and been replaced by a new olivine alignment in an opposing orientation to before.

Dr Eakin said: “The best way to explain this observation is that the slab’s interior must have been stretched or deformed during subduction. This means that slabs are weak enough to deform internally in the upper mantle over time.”

The researchers believe that deformation associated with stretching of the slab as it bends to takes on its flat-slab shape was enough to erase the frozen olivine structure and create a new alignment, which closely follows the contours of the slab bends.

“Imaging Earth’s plates once they have sunk back into the Earth is very difficult,” said Lara Wagner, from the Carnegie Institution for Science and a principal investigator of the PULSE Peruvian project. “It’s very exciting to see results that tell us more about their ultimate fate, and how the materials within them are slowly reworked by the planet’s hot interior. The original fabric in these plates stays stable for so long at the Earth’s surface, that it is eye opening to see how dramatically and quickly that can change,” Lara added.

Citation:University of Southampton. “Stretchy slabs found in the deep Earth.” ScienceDaily. ScienceDaily, 23 November 2015. <www.sciencedaily.com/releases/2015/11/151123202627.htm>

key: WFS,Riffin T Sajeev,Russel T Sajeev,World Fossil Society

first occurrence of a Dimetrodon fossil in Canada

November 25th, 2015

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A “dinosaur” fossil originally discovered on Prince Edward Island has been shown to have steak knife-like teeth, and researchers from U of T Mississauga, Carleton University and the Royal Ontario Museum have changed its name to Dimetrodon borealis–marking the first occurrence of a Dimetrodon fossil in Canada.

“It’s really exciting to discover that the detailed anatomy of the teeth has finally allowed us to identify precisely this important Canadian fossil,” says lead author Kirstin Brink, who did the research while at UTM. “Dimetrodon is actually more closely related to mammals than it is to dinosaurs.” In fact, it’s believed they went extinct some 40 million years before the dinosaurs.

The study appears in the November 23 issue of the Canadian Journal of Earth Sciences.

Dimetrodon is shown with an overlay of the “Bathygnathus” fossil from PEI, with a Walchia tree in the background (a common fossil found on PEI).
Credit: Illustration by Danielle Dufault

The fossil, previously known at Bathygnathus borealis, was collected in 1845 while a farmer was digging out a well on his property near French River, PEI. As there were no natural history museums in Canada at the time the fossil was found, it was sold to the Academy of Natural Sciences in Philadelphia, where Joseph Leidy–a preeminent paleontologist–could study and name it.

Leidy named the fossil Bathygnathus (meaning deep jaw) borealis (from the north) because he mistook it as the lower jaw of a dinosaur, similar to the large bipedal species that were being collected in Europe at the time.

The Bathygnathus specimen was the first “dinosaur,” and the second vertebrate fossil named from Canada (Dendrerpeton, an extinct amphibian from Nova Scotia, was named by Sir Richard Owen two months earlier). Several paleontologists have studied the Bathygnathus specimen since it was first named, but its precise identity was unknown. For example, it was unclear whether it had Dimetrodon‘s signature dorsal sail–created by tissue stretched between spines sticking up from its backbone–or lacked a sail like its smaller cousin Sphenacodon.

Using family trees and imaging techniques to see the internal anatomy of the fossil, researchers found that the eight preserved teeth linked the fossil to the Dimetrodon family–the first terrestrial animal to have “ziphodont” teeth.

“These are blade-like teeth with tiny serrations along the front and back of the teeth, similar to a steak knife,” says Professor Robert Reisz, the senior author of the study. “The roots of these teeth are very long, around double the length of the crowns. This type of tooth is very effective for biting and ripping flesh from prey.”

Fossils of Dimetrodon have now been found in the USA, Canada and Germany.

Ref: Kirstin S. Brink, Hillary C. Maddin, David C. Evans, Robert R. Reisz, Hans-Dieter Sues. Re-evaluation of the historic Canadian fossilBathygnathus borealisfrom the Early Permian of Prince Edward Island. Canadian Journal of Earth Sciences, 2015; 1 DOI: 10.1139/cjes-2015-0100<www.sciencedaily.com/releases/2015/11/151124112849.htm>.

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Intermediate Fossil Feathers Found

November 22nd, 2015

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A piece of amber formed of tree sap from 100 million years ago has preserved crucial evidence of feather evolution.
Evolution has long predicted the evolution of birds from reptiles, and recent discoveries of feathered dinosaurs has proved that model correct. However, the dinosaurs feathers found to date have been primitive in form, while bird fossils exhibit complex, barbed feathers required for flight.
This new fossil feathers, discovered in France, are intermediate in form between the simple downy feathers of early avian dinosaurs and the complex flight feathers of birds.

fossil feathers

Key: WFS,Riffin T Sajeev,Russel T Sajeev,World Fossil Society

Tyrannosaurus Could Open Jaw Really Wide ?

November 21st, 2015

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Tyrannosaurus rex and at least one other carnivorous dinosaur were capable of opening their jaws up to 90 degrees.

Plant-eating dinosaurs, on the other hand, were limited to a narrower jaw gape, suggesting that feeding style and diet of dinosaurs were closely linked to how wide they could open their mouths.

Recreation of Allosaurus fragilis with its jaws fully open.

Top 10 Largest Dinosaurs

“Theropod (carnivorous) dinosaurs, such as Tyrannosaurus rex or Allosaurus, are often depicted with widely-opened jaws, presumably to emphasize their carnivorous nature,” author Stephan Lautenschlager from the University of Bristol’s School of Earth Sciences said in a press release.

“Yet, up to now,” he continued, “no studies have actually focused on the relation between jaw musculature, feeding style and the maximal possible jaw gape.”

The study, published in the journal Royal Society Open Science, involved digital models, based on fossils, and computer analyses to recreate the muscle strain that likely occurred as dinosaurs opened their jaws.

The research looked at not only T. rex, but also another huge carnivore, Allosaurus fragilis, and plant eater Erlikosaurus andrewsi. Erlikosaurus andrewsi was an interesting choice, since this dino was closely related to the meat-eating dinosaurs, but was known to mainly eat plants.

The herbivore’s gape was just 45 degrees, equivalent to that of humans.

“All muscles, including those used for closing and opening the jaw, can only stretch a certain amount before they tear,” Lautenschlager said. “This considerably limits how wide an animal can open its jaws and therefore how, and on what, it can feed.”

Human evolution clearly benefited from cooking and other food processing innovations that allow us to eat a wide variety of foods without having very impressive jaw skills.

Among dinosaurs, T. rex appears to have had the best-sustained bite force, which would have allowed the dino to rip through flesh and skin, and to crush bone.

“We know from living animals that carnivores are usually capable of larger jaw gapes than herbivores, and it is interesting to see that this also appears to be the case in theropod dinosaurs,” Lautenschlager said.

In terms of living animals, hippos have an even wider bite than any dinosaur ever had, given that they can open up their jaws to an incredible 150 degrees. That means a 4-foot-tall individual could actually stand upright in a hippo’s open mouth.

Hippos are considered to be herbivores, but they have been observed scavenging on meat when their preferred food sources are scarce.

Courtesy:Article by by Jennifer Viegas

Key: WFS,Riffin T Sajeev,Russel T Sajeev,WorldFossil Society

Fossil Forests Discovered in the Arctic

November 20th, 2015

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Fossil Tree remnants

What did some of the first trees on Earth look like? Earth scientists from Cardiff University digging around in Arctic Norway are closing in on an answer. And that answer is: weirdly familiar.

Fossilized stumps from a forest dating back 380 million years indicate that these trees must have resembled palm trees covered in fern-like leaves. They grew close together and reached about 13 feet in height.

Cardiff University paleobotonist Chris Berry and his colleagues found the fossils in Svalbard, an archipelago that would have been located close to the equator hundreds of millions of years ago. They identified the trees as a now-extinct lycopod with the zippy name Protolepidodendropsis pulchra.

Reconstructed drawing of fossil forest in Svalbard.
Credit: Image courtesy of Cardiff University

Top 20 Reasons We’re Not as Powerful as We Think

The discovery of these strange forests could finally help explain a drastic drop in atmospheric carbon dioxide during the late Devonian time period. Just how drastic? It was a 15-fold reduction, a university press release said.

“It is rare fossil forests such as this that inform our understanding of the ecology and global distribution of large land plants during the transition to a forested planet,” the team wrote in the journal Geology.

This isn’t the first time Berry and his colleagues have pieced together an ancient forest. Back in 2012, he and his colleagues mapped out another Devonian forest that once grew in what is now Gilboa, N.Y., on the eastern side of the state.

Ancient Giant Trees Found Petrified in Thailand

“The fossil forest came to life in front of my eyes in a way that has never happened before,” he told Discovery News at the time.

These densely-packed ancient forests got me thinking. What if we could engineer a new tree with the powerful CO2-absorbing abilities of these early lycopods? They sound perfect for cities where space is at a premium. And with temperatures rising, I bet they’d thrive.

Ref: C. M. Berry, J. E. A. Marshall. Lycopsid forests in the early Late Devonian paleoequatorial zone of Svalbard. Geology, 2015; 43 (12): 1043 DOI: 10.1130/G37000.1

Key: WFS,Riffin T Sajeev,Russel T Sajeev,World Fossil Society

dinosaur-bird link

November 18th, 2015

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In the 19th century, Darwin’s most vocal scientific advocate was Thomas Henry Huxley, who is also remembered as a pioneer of the hypotheses that birds are living dinosaurs. He noticed several similarities of the skeleton of living birds and extinct dinosaurs, among them, a pointed portion of the anklebone projecting upwards onto the shank bone (aka drumstick). This “ascending process” is well known to specialists as a unique trait of dinosaurs. However, until the late 20th century, many scientists were doubtful about the dinosaur-bird link. Some pointed out that the ascending process in most birds was a projection of the neighbouring heel bone, rather than the anklebone. If so, it would not be comparable, and would not support the dinosaur-bird link.

Some argued that in bird embryos, the ascending process develops from the anklebone in dinosaur-like fashion, while others considered that its development in birds is unique and different from dinosaurs. Nowadays, the dinosaur-bird link is mainstream science, thanks to new methods of data analysis, and a dense series of intermediate fossils (including feathered dinosaurs). However, the disagreements about the composition and embryology of the avian ankle were never clarified fully. A new study in Nature Communications by Luis Ossa, Jorge Mpodozis and Alexander Vargas, from the University of Chile, provides a careful re-examination of ankle development in 6 different major groups of birds, selected specifically to clarify conditions in their last common ancestor. It also utilizes new techniques that allow three-dimensional analysis of fluorescent embryonic skeletons, using advanced spin-disc confocal microscopy and software.

Like modern amphibians, the remote ancestors of birds once had three bones in their upper ankle. When these evolved into landegg-laying animals, only two bones were present in this region. In dinosaurs, one of these, the anklebone, presents a pointed upward projection, the “ascending process”. This trait is also present in birds, which are living dinosaurs. A new detailed embryological study in birds reveals that their ankle has re-evolved an amphibian-like developmental pattern, with three separate elements, one of which becomes the dinosaurian ascending process
Credit: Image courtesy of Universidad de Chile

This work has revealed that the ascending process does not develop from either the heel bone or the ankle bone, but from a third element, the intermedium. In the ancient lineage of paleognath birds (such as tinamous, ostriches and kiwis) the intermedium comes closer to the anklebone, producing a dinosaur-like pattern. However, in the other major avian branch (neognaths), which includes most species of living birds, it comes closer to the heel bone; that creates the impression it is a different structure, when it is actually the same. “It puts the final nail in the anti-dinosaur coffin” says Jacques Gauthier, a vertebrate paleontologist and professor at Yale University “The dinosaurian ascending process is retained in all birds, though it has changed its association from ankle to heel bones in neognath birds.”

More remarkably, however, this finding reveals an unexpected evolutionary transformation in birds. In embryos of the landegg-laying animals, the amniotes (which include crocodilians, lizards, turtles, and mammals, who secondarily evolved live birth) the intermedium fuses to the anklebone shortly after it forms, disappearing as a separate element. This does not occur in the bird ankle, which develops more like their very distant relatives that still lay their eggs in water, the amphibians. Since birds clearly belong within landegg-laying animals, their ankles have somehow resurrected a long-lost developmental pathway, still retained in the amphibians of today — a surprising case of evolutionary reversal. The study also presented fossil evidence from juvenile specimens of toothed birds from the Cretaceous period. These show that, at this early stage of bird evolution, the ascending process already developed separately.

Evolutionary reversions have always generated much discussion among scientists, because ancient traits can occasionally re-appear in a highly transformed context. A recent paper in BMC Evolutionary Biology (Diaz and Trainor, 2015) has revealed that chameleons also re-evolved an independent intermedium, in the specialized functional context of a climbing reptile. The reappearance of this long-lost developmental pattern in highly evolved organisms like birds and chameleons could be compared to finding primitive clockwork gears inside your latest smartphone. These intriguing discoveries are bound to renew discussion about the interplay between the evolution of new functions and the resurrection of old developmental patterns.

Citation:Universidad de Chile. “The dinosaur ankle re-evolved amphibian-like development in birds.” ScienceDaily. ScienceDaily, 13 November 2015. <www.sciencedaily.com/releases/2015/11/151113105924.htm>.

Key: WFS,Riffin T Sajeev,Russel T sajeev,World Fossil Society

Oceanic microplate formation records the onset of India–Eurasia collision

November 15th, 2015

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An international team of scientists has discovered the first oceanic microplate in the Indian Ocean–helping identify when the initial collision between India and Eurasia occurred, leading to the birth of the Himalayas.

Although there are at least seven microplates known in the Pacific Ocean, this is the first ancient Indian Ocean microplate to be discovered. Radar beam images from an orbiting satellite have helped put together pieces of this plate tectonic jigsaw and pinpointed the age for the collision, whose precise date has divided scientists for decades.

Reported in Earth and Planetary Science Letters, the team of Australian and US scientists believe the collision occurred 47 million years ago when India and Eurasia initially smashed into each other.

Researchers led by the University of Sydney School of Geosciences discovered that crustal stresses caused by the initial collision cracked the Antarctic Plate far away from the collisional zone and broke off a fragment the size of Australia’s Tasmania in a remote patch of the central Indian Ocean.

The authors, comprising Professor Dietmar Müller and Dr Kara Matthews from the University of Sydney and Professor David Sandwell from the Scripps Institution of Oceanography, have named the ancient Indian microplate the Mammerickx Microplate, after Dr Jacqueline Mammerickx, a pioneer in seafloor mapping.

The Mammerickx Microplate rotation is revealed by a rotating pattern of grooves and hills that turn the topography of the ocean floor into a jagged landscape. These so-called “abyssal hills” record a sudden increase in crustal stress, dating the birth of the Himalayan Mountain Range to 47 million years ago.

The ongoing tectonic collision between the two continents produces geological stresses that build up along the Himalayas and leads to numerous earthquakes every year–but this latest finding indicates how stressed the Indian Plate became when its northern edge first collided with Eurasia.

The new research shows that 50 million years ago, India was travelling northwards at speeds of some 15 centimetres a year–close to the plate tectonic speed limit. Soon after it slammed into Eurasia crustal stresses along the mid-ocean ridge between India and Antarctica intensified to breaking point. A chunk of Antarctica’s crust broke off and started rotating like a ball bearing, creating the newly discovered tectonic plate.

The discovery was made using satellite radar beam mapping from space, which measures the bumps and dips of the sea surface caused by water being attracted by submarine mountains and valleys, combined with conventional marine geophysical data.

Lead author Dr Matthews explains: “The age of the largest continental collision on Earth has long been controversial, with age-estimates ranging from at least 59 to 34 million years ago.

“Knowing this age is particularly important for understanding the link between the growth of mountain belts and major climate change.”

Co-author Professor Müller said: “Dating this collision requires looking at a complex set of geological and geophysical data, and no doubt discussion about when this major collision first started will continue, but we have added a completely new, independent observation, which has not been previously used to unravel the birth of this collision.

“It is beyond doubt that the collision must have led to a major change in India’s crustal stress field–that’s why the plate fragmentation we mapped is a bit like a smoking gun for pinning down the collision age.”

Co-author Professor Sandwell from the Scripps Institution of Oceanography said humans had explored and mapped remote lands extensively but the same was not true for our ocean basins.

“We have more detailed maps of Pluto than we do of most of our own planet because about 71 per cent of the Earth’s surface is covered with water,” Professor Sandwell said.

“Roughly 90% of the seafloor is uncharted by ships and it would take 200 ship-years of time to make a complete survey of the deep ocean outside continental shelves, at a cost of between two- to three billion US dollars.

“That’s why advances in comparatively low-cost satellite technology are the key to charting the deep, relatively unknown abyssal plains, at the bottom of the ocean.”

The paper ‘Oceanic microplate formation records the onset of India-Eurasia collision’ was be published in Earth and Planetary Science Letters last week.

Citation:Kara J. Matthews, R. Dietmar Müller, David T. Sandwell. Oceanic microplate formation records the onset of India–Eurasia collision. Earth and Planetary Science Letters, 2015;

Key: WFS,Riffin T Sajeev,Russel T Sajeev,World Fossil Society

This is the newly discovered tectonic plate, named Mammerickx Microplate.
Credit: University of Sydney

Predatory Functional Morphology in Raptors

November 13th, 2015

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Despite the ubiquity of raptors in terrestrial ecosystems, many aspects of their predatory behaviour remain poorly understood. Surprisingly little is known about the morphology of raptor talons and how they are employed during feeding behaviour. Talon size variation among digits can be used to distinguish families of raptors and is related to different techniques of prey restraint and immobilisation. The hypertrophied talons on digits (D) I and II in Accipitridae have evolved primarily to restrain large struggling prey while they are immobilised by dismemberment. Falconidae have only modest talons on each digit and only slightly enlarged D-I and II. For immobilisation, Falconini rely more strongly on strike impact and breaking the necks of their prey, having evolved a ‘tooth’ on the beak to aid in doing so. Pandionidae have enlarged, highly recurved talons on each digit, an adaptation for piscivory, convergently seen to a lesser extent in fishing eagles. Strigiformes bear enlarged talons with comparatively low curvature on each digit, part of a suite of adaptations to increase constriction efficiency by maximising grip strength, indicative of specialisation on small prey. Restraint and immobilisation strategy change as prey increase in size. Small prey are restrained by containment within the foot and immobilised by constriction and beak attacks. Large prey are restrained by pinning under the bodyweight of the raptor, maintaining grip with the talons, and immobilised by dismemberment (Accipitridae), or severing the spinal cord (Falconini). Within all raptors, physical attributes of the feet trade off against each other to attain great strength, but it is the variable means by which this is achieved that distinguishes them ecologically. Our findings show that interdigital talon morphology varies consistently among raptor families, and that this is directly correlative with variation in their typical prey capture and restraint strategy.

Feet of representative raptors.
Note the digit length and relative enlargement and curvature of claws within each foot: Accipitridae bear hypertrophied talons on D-I and II; Falconidae have only modest talons on each digit and only slightly enlarged D-I and II; Strigiformes bear large talons with comparatively low curvature on each digit; Pandionidae have enlarged, highly recurved talons on each digit. (A) Accipitridae: goshawk, Accipiter gentilis, MOR OST-1276; (B), Accipitridae: red-tailed hawk, Buteo jamaicensis MOR OST-1275; (C) Falconidae: peregrine falcon, Falco peregrinus, MOR OST-1265; (D) Strigiformes: great grey owl, Strix nebulosa, MOR OST-1284; (E) Pandionidae: osprey, Pandion haliaetus, MOR OST-1268.
doi:10.1371/journal.pone.0007999.g001

Size and curvature measurements taken from each claw, using methodology of Pike and Maitland (2004).
(A) Outer curvature measurements. ALo, arc length from claw base to tip; Ao, straight line (chord) distance from claw base to tip; Hmo, height of claw at midpoint; Oo, angle of curvature. (B) Inner curvature measurements. ALi, arc length from claw base to tip; Ai, straight line (chord) distance from claw base to tip; Hmi, height of claw at midpoint; Hp, height of claw at base; Oi, angle of curvature.
doi:10.1371/journal.pone.0007999.g002

Citation: Fowler DW, Freedman EA, Scannella JB (2009) Predatory Functional Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique. PLoS ONE 4(11): e7999. doi:10.1371/journal.pone.0007999

Editor: Tom Pizzari, University of Oxford, United Kingdom

Key: WFS, Riffin T Sajeev,Russel T Sajeev, World Fossil Society

Rat fossils of largest rat that ever existed

November 9th, 2015

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Archaeologists with The Australian National University (ANU) have discovered fossils of seven giant rat species on East Timor, with the largest up to 10 times the size of modern rats.

Dr Julien Louys of the ANU School of Culture, History and Language, who is helping lead the project said these are the largest known rats to have ever existed.

“They are what you would call mega-fauna. The biggest one is about five kilos, the size of a small dog,” Dr Louys said.

“Just to put that in perspective, a large modern rat would be about half a kilo.”

The work is part of the From Sunda to Sahul project which is looking at the earliest human movement through Southeast Asia. Researchers are now trying to work out exactly what caused the rats to die out.

Dr. Julien Louys holds the jaw bone of a giant rat species discovered on East Timor, up against a comparison with the same bone of a modern rat. Credit: Stuart Hay, ANU

Dr Louys said the earliest records of humans on East Timor date to around 46,000 years ago, and they lived with the rats for thousands of years.

“We know they’re eating the giant rats because we have found bones with cut and burn marks,” he said.

“The funny thing is that they are co-existing up until about a thousand years ago. The reason we think they became extinct is because that was when metal tools started to be introduced in Timor, people could start to clear forests at a much larger scale.”

Dr Louys said the project team is hoping to get an idea of when humans first moved through the islands of Southeast Asia, how they were doing it and what impact they had on the ecosystems. The information can then be used to inform modern conservation efforts.

“We’re trying to find the earliest human records as well as what was there before humans arrived,” Dr Louys said.

“Once we know what was there before humans got there, we see what type of impact they had.”

Dr Louys returned from the project’s latest expedition to East Timor in August and has presented the findings at the Meetings of the Society of Vertebrate Palaeontology in Texas.

Citation: Australian National University. “Rat fossils of largest rat that ever existed.” ScienceDaily. ScienceDaily, 6 November 2015. <www.sciencedaily.com/releases/2015/11/151106113858.htm>.

Key: WFS,Riffin T Sajeev, Russel T Sajeev, World Fossil Society

Eotiaris guadalupensis : The oldest sea urchin

November 5th, 2015

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Researchers have uncovered a fossil sea urchin that pushes back a fork in its family tree by 10 million years, according to a new study.

A team from USC found the Eotiaris guadalupensis in the collections of the Smithsonian Institution from the Glass Mountains of west Texas, where it had been buried in a rock formation that dates back to 268.8 million years at its youngest.

“This fossil pushes the evolution of this type of sea urchin from the Wuchiapingian age all the way back to the Roadian age,” said David Bottjer, professor at the USC Dornsife College of Letters, Arts and Sciences, and senior author of a paper announcing the find that appeared in Nature Scientific Reports on October 21.

Eotiaris guadalupensis fossil was discovered by USC’s Jeffrey Thompson in the Smithsonian collections.
Credit: Courtesy of David Bottjer/USC

This paper was a collaboration between Bottjer’s lab and Eric Davidson’s lab at Caltech. Jeffrey Thompson, a Ph.D. student at USC and was the lead author of the study, found the fossils of Eotiaris guadalupensis in the Smithsonian collections.

Eotiaris guadalupensis is a cidaroid, one of the two main types of sea urchins found in today’s oceans. The other group, the euechinoids, evolved wildly varying body types and accounts for almost all sea urchins alive today. Cidaroids, by contrast, look pretty much the same as they did millions of years ago. Both evolved from an ancestral group of echinoids known as the Archaeocidaridae, which are now extinct.

The divergence of the two groups marks a major — and relatively abrupt — shift in the genetic organization of sea urchins.

“It’s not just the color of a moth’s wing changing,” said Bottjer, referring to the classic example of the peppered moth in England that, in the post-Industrial Revolution’s sooty skies, began to appear in a darker color. “We’re looking at tightly intertwined networks of genes that change together to cause major morphological differences.”

Pinning down the time at which the two groups diverged allows evolutionary biologists to better understand the processes that occur during major evolutionary changes.

Bottjer and Thompson will also expand on these findings at the Geological Society of America meeting in Baltimore on November 3 and 4, when they will discuss in separate presentations the burgeoning field of paleogenomics — tracking morphological innovations from the fossil record which are produced by know genes in modern organisms, to date when these genes first evolved.

Journal Citation:Jeffrey R. Thompson, Elizabeth Petsios, Eric H. Davidson, Eric M. Erkenbrack, Feng Gao, David J. Bottjer. Reorganization of sea urchin gene regulatory networks at least 268 million years ago as revealed by oldest fossil cidaroid echinoid. Scientific Reports, 2015; 5: 15541 DOI: 10.1038/srep15541

Key: WFS,Riffin T Sajeev,Russel T Sajeev,World Fossil Society