Bryozoans: Fossil fills missing evolutionary link

Lurking in oceans, rivers and lakes around the world are tiny, ancient animals known to few people. Bryozoans, tiny marine creatures that live in colonies, are “living fossils” — their lineage goes back to the time when multi-celled life was a newfangled concept. But until now, scientists were missing evidence of one important breakthrough that helped the bryozoans survive 500 million years as the world changed around them.

Today, the diverse group of bryozoans that dominate modern seas build a great range of structures, from fans to sheets to weird, brain-like blobs. But for the first 50 or 60 million years of their existence, they could only grow like blankets over whatever surface they happened upon.

Scientists recently announced the discovery of that missing evolutionary link — the first known member of the modern bryozoans to grow up into a structure. Called Jablonskipora kidwellae, it is named after UChicago geophysical scientists David Jablonski and Susan Kidwell.

Both are prominent scholars in their fields: Jablonski in origins, extinctions and other forces shaping biodiversity across time and space in marine invertebrates; Kidwell in the study of how fossils are preserved and the reliability of paleobiologic data, especially for detecting recent, human-driven changes to ecosystems. They also happen to be married.

“We were absolutely thrilled. What a treat and an honor, to have this little guy named after us,” said Jablonski, the William R. Kenan Jr. Distinguished Service Professor of Geophysical Sciences.

“I never expected to have a fossil named after me,” said Kidwell, the William Rainey Harper Professor in Geophysical Sciences, “and here it’s one that is an evolutionary breakthrough. We’re still smiling about it.”

Jablonskipora kidwellae lived about 105 million years ago, latching on to rocks and other hard surfaces in shallow seas — a bit like corals, though they’re not related. The fossils came from southwest England, along cliffs near Devon, originally collected in 1903 and analyzed by co-discoverers Paul Taylor and Silviu Martha from London’s Natural History Museum.

Bryozoans never figured out a symbiotic partnership with photosynthetic bacteria, as coral did, so their evolution took a different turn. Each one in a colony is genetically identical, but they have specialized roles, like ants or bees. Their shelly apartment complexes house thousands of the creatures, which have soft bodies with tiny tentacles to catch nutrients.

Growing upright was an evolutionary hack for Jablonskipora kidwellae, the two professors said: building bigger colonies extending upward from just a tiny attachment site was a good evolutionary move, allowing it to tap the water flowing above the sea floor — both for food and to scatter its offspring further. “This is a huge competitive advantage for them,” Jablonski said, “but it required some evolutionary organization to create a vertical structure.” Kidwell added: “This is the next level of cooperation among these individuals within the colony.”

They expressed a fondness for the creature, which they said was, like other bryozoans, “small and slow, but fierce.” Bryozoan fossils are sometimes found having bulldozed right over neighboring colonies in an intense battle for growing space. In a manner of speaking: this all would have taken place in extremely slow motion.

“They’re pretty fabulous little animals,” Kidwell said.

Jablonski and Kidwell have been friends with Taylor, one of the discoverers, since they spent summers on various research at the London Natural History Museum in the 1980s, but they said his news took them both completely by surprise. Jablonski had previously co-authored one paper with Taylor; Kidwell is currently collaborating with him on a study of bryozoan skeletal debris in modern sediments from the Channel Islands off Los Angeles.

It is the second honor of the year for both Kidwell and Jablonski: In April she received the Moore Medal from the Society for Sedimentary Geology, and in October he received the Paleontological Society Medal, that society’s highest honor.

Jablonski had one previous species named after him — a tiny clam — but Jablonskiporawill now be a genus in addition to a species.

Story Source:

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

Colorado River’s connection with the ocean was a punctuated affair

The Colorado River’s initial trip to the ocean didn’t come easy, but its story has emerged from layers of sediment preserved within tectonically active stretches of the waterway’s lower reaches.

A scientific team, led by geologist Rebecca Dorsey of the University of Oregon, theorizes that the river’s route off the Colorado Plateau was influenced by a combination of tectonic deformation and changing sea levels that produced a series of stops and starts between roughly 6.3 and 4.8 million years ago.

Dorsey’s team lays out its case in an invited-research paper in the journal Sedimentary Geology. The team’s interpretation challenges long-held conventional thinking that once a river connects to the ocean it’s a done deal.

“The birth of the Colorado River was more punctuated and filled with more uneven behavior than we expected,” Dorsey said. “We’ve been trying to figure this out for years. This study is a major synthesis of regional stratigraphy, sedimentology and micropaleontology. By integrating these different datasets we are able to identify the different processes that controlled the birth and early evolution of this iconic river system.”

The region covered in the research stretches from the southern Bouse Formation, near present-day Blythe, California, to the western Salton Trough north of where the river now trickles into the Gulf of California. The Bouse Formation and deposits in the Salton Trough have similar ages and span both sides of the San Andreas Fault, providing important clues to the river’s origins.

Last year, in the journal Geology, a project led by graduate student Brennan O’Connell, a co-author on the new study, concluded that laminated sediments found in exposed rock along the river near Blythe were deposited by tidal currents 5.5 million years ago. The Gulf of California, it was argued, extended into the region, but the age of the deposits and tectonic and sea level changes at work during that time were not well understood.

Analyses by Kristin McDougall, a micropaleontologist with the U.S. Geological Survey and co-author on the new paper, helped the team better pinpoint the timing of the limestone deposits to about 6 million years ago, when tiny marine organisms lived in the water and were deposited at the same time.

About 5.4 million years ago, conditions changed. Global sea level was falling but instead of bay water levels declining, as would be expected, the water depth increased due to tectonic subsidence of the crust, the researchers discovered.

The basal carbonate material left by marine organisms was then inundated by fresh water as the river swept down into lower elevations, bringing with it clay and sand from mountain terrain, they found.

“The bay filled up with river sediment as the sediment migrated toward the ocean,” Dorsey said. “As more sediment came in, transport processes caused the delta front to move down the valley, transforming the marine bay into a delta and then the earliest through-flowing Colorado River.”

The river had arrived in the gulf, but only temporarily. A tug-of-war lasting for 200,000 to 300,000 years began some 5.1 million years ago, when the river stopped delivering sediments from upstream. The delta retreated and seawater returned to the lower Colorado River valley for a short time. The evidence is in the stratigraphy and fossils. Researchers found that clay and sand from the river became mixed with and then covered by marine sediment.

Something, Dorsey said, apparently was happening upstream, trapping river sediment. A good bet, the researchers think, is tectonic activity, perhaps earthquakes along a fault zone in the river’s northern basin that created subsidence in the riverbed or deep lakes along the river’s path.

At roughly 4.8 million years ago, the river resumed depositing massive amounts of sediment back into the Salton Trough and began rebuilding the delta. Today’s view of the delta, however, reflects human-made modern disturbances to the river’s sediment discharge and flow of water reaching the gulf.

To meet agricultural demands for irrigation and drinking water for human consumption, Hoover Dam was constructed on the river to form Lake Mead during the 1930s. In 1956-1966, Glen Canyon Dam was built, forming Lake Powell.

“If we could go back to 1900 before the dams that trap the sediment and water, we would see that the delta area was full of channels, islands, sand bars and moving sediment. It was a very diverse, dynamic and rich delta system. But humanmade dams are trapping sediment today, eerily similar to what happened roughly 5 million years ago,” Dorsey said.

The bottom line of the research, she said, is that no single process controlled the Colorado River’s initial route to the sea. “Different processes interacted in a surprisingly complicated sequence of events that led to the final integration of that river out to the ocean,” she said.

The research, Dorsey said, provides insights that help scientists understand how such systems change through time. The Colorado River is an excellent natural laboratory, she said, because sedimentary deposits that formed prior to and during river initiation are well exposed throughout the lower river valley.

“This research,” Dorsey said, “is very relevant to today because we have global sea level rising, climate is warming, coastlines are being inundated and submerged, and the supply of river sediment exerts a critical control on the fate of deltas where they meet the ocean. Documenting the complex interaction of these processes in the past helps us understand what is happening today.”

Story Source:

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

World’s longest sauropod dinosaur trackway brought to light

In 2009, the world’s largest dinosaur tracks were discovered in the French village of Plagne, in the Jura Mountains. Since then, a series of excavations at the site has uncovered other tracks, sprawling over more than 150 meters. They form the longest sauropod trackway ever to be found. Having compiled and analyzed the collected data, which is published in Geobios, scientists from the Laboratoire de Géologie de Lyon (CNRS / ENS de Lyon / Claude Bernard Lyon 1 University), the Laboratoire Magmas et Volcans (CNRS / Université Clermont Auvergne / Université Jean Monnet / IRD), and the Pterosaur Beach Museum conclude these tracks were left 150 million years ago by a dinosaur at least 35 m long and weighing no less than 35 t.

In 2009, when sauropod tracks were discovered in the French village of Plagne — near Lyon — the news went round the world. After two members of the Oyonnax Naturalists’ Society spotted them, scientists from the Paléoenvironnements et Paléobiosphère research unit (CNRS / Claude Bernard Lyon 1 University) confirmed these tracks were the longest in the world. Between 2010 and 2012, researchers from the Laboratoire de Géologie de Lyon supervised digs at the site, a meadow covering three hectares. Their work unearthed many more dinosaur footprints and trackways. It turns out the prints found in 2009 are part of a 110-step trackway that extends over 155 m — a world record for sauropods, which were the largest of the dinosaurs.

Dating of the limestone layers reveals that the trackway was formed 150 million years ago, during the Early Tithonian Age of the Jurassic Period. At that time, the Plagne site lay on a vast carbonate platform bathed in a warm, shallow sea. The presence of large dinosaurs indicates the region must have been studded with many islands that offered enough vegetation to sustain the animals. Land bridges emerged when the sea level lowered, connecting the islands and allowing the giant vertebrates to migrate from dry land in the Rhenish Massif.

Additional excavations conducted as late as 2015 enabled closer study of the tracks. Those left by the sauropod’s feet span 94 to 103 cm and the total length can reach up to 3 meters when including the mud ring displaced by each step. The footprints reveal five elliptical toe marks, while the handprints are characterized by five circular finger marks arranged in an arc. Biometric analyses suggest the dinosaur was at least 35 m long, weighted between 35 and 40 t, had an average stride of 2.80 m, and traveled at a speed of 4 km/h. It has been assigned to a new ichnospecies1: Brontopodus plagnensis. Other dinosaur trackways can be found at the Plagne site, including a series of 18 tracks extending over 38 m, left by a carnivore of the ichnogenus Megalosauripus. The researchers have since covered these tracks to protect them from the elements. But many more remain to be found and studied in Plagne.

1 The prefix ichno- indicates that a taxon (e.g., a genus or species) has been defined on the basis of tracks or other marks left behind, rather than anatomical remains like bones.

Story Source:

Materials provided by CNRS. Note: Content may be edited for style and length.

Finger and toe fossils belonged to tiny primates 45 million years ago

At Northern Illinois University, Dan Gebo opens a cabinet and pulls out a drawer full of thin plastic cases filled with clear gelatin capsules. Inside each numbered capsule is a tiny fossil — some are so small they rival the diminutive size of a mustard seed.

It’s hard to imagine that anyone would be able to recognize these flecks as fossils, much less link them to an ancient world that was very different from our own, yet has quite a bit to do with us — or the evolution of us.

The nearly 500 finger and toe bones belonged to tiny early primates — some half the size of a mouse. During the mid-Eocene period, about 45 million years ago, they lived in tree canopies and fed on fruit and insects in a tropical rainforest in what is now China.

The fossilized phalanges are described in detail in a new study by Gebo and colleagues, published online this fall ahead of print in the Journal of Human Evolution.

Representing nine different taxonomic families of primates and as many as 25 species, the specimens include numerous fossils attributed to Eosimias, the very first anthropoid known to date, and three fossils attributed to a new and much more advanced anthropoid. The anthropoid lineage would later include monkeys, apes and humans.

“The fossils are extraordinarily small, but in terms of quantity this is the largest single assemblage of fossil primate finger and toe specimens ever recorded,” said Gebo, an NIU professor of anthropology and biology who specializes in the study of primate anatomy.

All of the finger and toe fossils imply tree-dwelling primates with grasping digits in both hands and feet. Many of the smaller fossils are between 1 and 2 millimeters in length, and the animals would have ranged in full body size from 10 to 1,000 grams (0.35 to 35.3 ounces).

“The new study provides further evidence that early anthropoids were minuscule creatures, the size of a mouse or smaller,” Gebo said. “It also adds to the evidence pointing toward Asia as the initial continent for primate evolution. While apes and fossil humans do come from Africa, their ancestors came from Asia.”

The newly described fossils were originally recovered from a commercial quarry near the village of Shanghuang in the southern Jiangsu Province of China, about 100 miles west of Shanghai. In recent decades, Shanghuang has become well-known among paleontologists.

“Shanghuang is truly an amazingly diverse fossil primate locality, unequaled across the Eocene,” Gebo said. “Because no existing primate communities show this type of body-size distribution, the Shanghuang primate fauna emphasizes that past ecosystems were often radically different from those we are familiar with today.”

Co-author Christopher Beard, a paleontologist at the University of Kansas in Lawrence who has been working on Shanghuang fossils for 25 years, said the limestone in the quarry is of Triassic age — from the very beginning of the Age of Dinosaurs some 220 million years ago. Owing to a subsequent phase of erosion, the limestone developed large fissures containing fossil-rich sediments dating to the middle Eocene, after dinosaurs went extinct.

In the early 1990s, more than 10 tons of fossil-bearing matrix were collected from the fissures and shipped to the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and the Carnegie Museum of Natural History in Pittsburgh. There, the matrix was washed and screened, yielding fossil bones and teeth from ancient mammals, many of which remain to be identified.

“Because of commercial exploitation of the quarry site, the fossil-bearing fissure-fillings at Shanghuang are now exhausted,” Beard said. “So, the fossils that we currently have are all that will ever be found from this site.”

Gebo was initially recruited during the late 1990s to spearhead research on primate limb and ankle bones from Shanghuang. That led to two publications in 2000, when he and colleagues first announced the discovery of 45 million-year-old, thumb-length primates, the smallest ever recovered, from this same site. The work identifying body parts also helped cement the status of Eosimias, first identified by Beard on the basis of jaw fragments discovered at the site, as an extremely primitive anthropoid lying at the very beginning of our lineage’s evolutionary past.

In more recent years, Gebo found additional specimens, sifting through miscellaneous elements from Shanghuang both at the Carnegie Museum and the University of Kansas. He brought the delicate and minuscule finger and toe fossils to NIU for study using traditional and electron-scanning microscopes.

The fossils that endured the millennia may be small but still have a story to tell. “We can actually identify different types of primates from the shapes of their fingers and toes,” Gebo said.

Primates are mammals, characterized by having bigger brains, grasping hands and feet, nails instead of claws and eyes located in the front of the skull. Living prosimians, or living lower primates, include lemurs and tarsiers, and have broader fingertips. In contrast, most living anthropoids, also known as higher primates, have narrow fingertips.

Fossils from the unnamed advanced anthropoid are narrow, Gebo said.

“These are the earliest known examples of those narrow fingers and toes that are key to anthropoid evolution,” he added. “We can see evolution occurring at this site, from the broader finger or toe tips to more narrow.”

Unlike other prehistoric forests across the globe that have a mixture of large and small primates, Shanghuang’s fossil record is unique in being nearly absent of larger creatures.

The unusual size distribution is likely the result of a sampling bias, Gebo said. Researchers might be missing the larger primate fauna because of processes affecting fossil preservation, and for similar reasons scientists at other Eocene localities could be missing the small-sized fauna.

“Many of the fossil specimens from Shanghuang show evidence of partial digestion by predatory birds, which may have specialized on preying upon the small primates and other mammals that are so common at Shanghuang, thus explaining the apparent bias toward small fossil species there,” Beard added.

Some of the primate fossils found in Shanghuang are found in other countries. Eosimias fossils have been recovered in Myanmar, for example. But Shanghuang stands out because of the presence of more advanced anthropoids and the sheer diversity of primates.

“You don’t find all of these fossil primates in one place except at Shanghuang,” Gebo said.

Story Source:

Materials provided by Northern Illinois University. Note: Content may be edited for style and length.

Humankind’s earliest ancestors discovered in southern England

Fossils of the oldest mammals related to humankind have been discovered on the Jurassic Coast of Dorset.
The two teeth are from small, rat-like creatures that lived 145 million years ago in the shadow of the dinosaurs. They are the earliest undisputed fossils of mammals belonging to the line that led to human beings.

They are also the ancestors to most mammals alive today, including creatures as diverse as the Blue Whale and the Pigmy Shrew. The findings are published in the Journal, Acta Palaeontologica Polonica, in a paper by Dr Steve Sweetman, Research Fellow at the University of Portsmouth, and co-authors from the same university. Dr Sweetman, whose p

rimary research interest concerns all the small vertebrates that lived with the dinosaurs, identified the teeth but it was University of Portsmouth undergraduate student, Grant Smith who made the discovery.

Dr Sweetman said: “Grant was sifting through small samples of earliest Cretaceous rocks collected on the coast of Dorset as part of his undergraduate dissertation project in the hope of finding some interesting remains. Quite unexpectedly he found not one but two quite remarkable teeth of a type never before seen from rocks of this age. I was asked to look at them and give an opinion and even at first glance my jaw dropped!”

“The teeth are of a type so highly evolved that I realised straight away I was looking at remains of Early Cretaceous mammals that more closely resembled those that lived during the latest Cretaceous — some 60 million years later in geological history. In the world of palaeontology there has been a lot of debate around a specimen found in China, which is approximately 160 million years old. This was originally said to be of the same type as ours but recent studies have ruled this out. That being the case, our 145 million year old teeth are undoubtedly the earliest yet known from the line of mammals that lead to our own species.”

Dr Sweetman believes the mammals were small, furry creatures and most likely nocturnal. One, a possible burrower, probably ate insects and the larger may have eaten plants as well.

He said: “The teeth are of a highly advanced type that can pierce, cut and crush food. They are also very worn which suggests the animals to which they belonged lived to a good age for their species. No mean feat when you’re sharing your habitat with predatory dinosaurs!”

The teeth were recovered from rocks exposed in cliffs near Swanage which has given up thousands of iconic fossils. Grant, now reading for his Master’s degree at The University of Portsmouth, said that he knew he was looking at something mammalian but didn’t realise he had discovered something quite so special. His supervisor, Dave Martill, Professor of Palaeobiology, confirmed that they were mammalian, but suggested Dr Sweetman, a mammal expert should see them.

Professor Martill said: “We looked at them with a microscope but despite over 30 years’ experience these teeth looked very different and we decided we needed to bring in a third pair of eyes and more expertise in the field in the form of our colleague, Dr Sweetman.

“Steve made the connection immediately, but what I’m most pleased about is that a student who is a complete beginner was able to make a remarkable scientific discovery in palaeontology and see his discovery and his name published in a scientific paper. The Jurassic Coast is always unveiling fresh secrets and I’d like to think that similar discoveries will continue to be made right on our doorstep.”

One of the new species has been named Durlstotherium newmani, christened after Charlie Newman, the landlord of the Square and Compass pub in Worth Matravers, close to where the fossils were discovered.

Story Source:

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

New species of dinosaur increases the already unexpected diversity of ‘whiplash dinosaurs’

Researchers from Italy and Portugal describe yet another new sauropod species from 150 million years ago, from Wyoming, USA.

The new species, Galeamopus pabsti, is the most recent dinosaur to be described by paleontologists from the Department of Earth Sciences of the University of Turin, Italy; the Faculty of Science and Technology, Universidade Nova de Lisboa, and the Museum of Lourinhã in Portugal. This Jurassic dinosaur was originally excavated in 1995 by a Swiss team, led by Hans-Jakob “Kirby” Siber and Ben Pabst, in Wyoming, in the United States and is the latest in a series of new discoveries by the paleontologists Emanuel Tschopp and Octávio Mateus, which started in 2012 with Kaatedocus siberi. The paper describing the new species was published online in the open access scientific journal PeerJ on Tuesday, May 2.

Galeamopus pabsti is similar to the famous dinosaur Diplodocus, but with more massive legs, and a particularly high and triangular neck close to the head. It is the second species of the genus Galeamopus to be shown to be different to Diplodocus by the same researchers (the first being published in 2015, in a paper which also reinstated the brontosaurus as a distinct genus). The new species is dedicated to Ben Pabst, who found the skeleton, and prepared it for mounting at the Sauriermuseum Aathal in Switzerland, where it is one of the main attractions of the permanent exhibit.

Diplodocid sauropods are among the most iconic dinosaurs. With their greatly elongated necks and tails, they represent the typical body shape of sauropods. Species of this group occur also in Africa, South America, and Europe, but the highest diversity is known from the USA: more than 15 species of these gigantic animals are known from there, also including the famous Brontosaurus. Researchers are still baffled by this high diversity of giants, and are continuing their studies to understand how such a diversity could be maintained by the ecosystem in which they lived.

Story Source:

Materials provided by PeerJ. Note: Content may be edited for style and length.

Earliest relative of Brachiosaurus dinosaur found in France

Scientists have re-examined an overlooked museum fossil and discovered that it is the earliest known member of the titanosauriform family of dinosaurs.

The fossil, which the researchers from Imperial College London and their colleagues in Europe have named Vouivria damparisensis, has been identified as a brachiosaurid sauropod dinosaur.

The researchers suggest the age of Vouivria is around 160 million years old, making it the earliest known fossil from the titanosauriform family of dinosaurs, which includes better-known dinosaurs such as the Brachiosaurus. When the fossil was first discovered in France in the 1930s, its species was not identified, and until now it has largely been ignored in scientific literature.

The new analysis of the fossil indicates that Vouivria died at an early age, weighed around 15,000 kilograms and was over 15 metres long, which is roughly 1.5 times the size of a double-decker bus in the UK.

It had a long neck held at around a 45 degree angle, a long tail, and four legs of equal length. It would have been a plant eater.

Dr Philip Mannion, the lead author of the study from the Department of Earth Science and Engineering at Imperial College London, said: “Vouivria would have been a herbivore, eating all kinds of vegetation, such as ferns and conifers. This creature lived in the Late Jurassic, around 160 million years ago, at a time when Europe was a series of islands. We don’t know what this creature died from, but millions of years later it is providing important evidence to help us understand in more detail the evolution of brachiosaurid sauropods and a much bigger group of dinosaurs that they belonged to, called titanosauriforms.”

Titanosauriforms were a diverse group of sauropod dinosaurs and some of the largest creatures to have ever lived on land. They lived from at least the Late Jurassic, right to the end-Cretaceous mass extinction, when an asteroid wiped out most life on Earth.

A lack of fossil records means that it has been difficult for scientists to understand the early evolution of titanosauriforms and how they spread out across the planet. The re-classification of Vouivria as an early titanosauriform will help scientists to understand the spread of these creatures during the Early Cretaceous period, a later period of time, after the Jurassic, around 145 — 100 million years ago.

The team’s incorporation of Vouivria into a revised analysis of sauropod evolutionary relationships shows that by the Early Cretaceous period, brachiosaurids were restricted to what is now Africa and the USA, and were probably extinct in Europe.

Previously, scientists had suggested the presence of another brachiosaurid sauropod dinosaur called Padillasaurus much further afield in what is now South America, in the Early Cretaceous. However, the team’s incorporation of Vouivria into the fossil timeline suggests that Padillasaurus was not a brachiosaurid, and that this group did not spread as far as South America.

The Vouivria fossil was originally discovered by palaeontologists in the village of Damparis, in the Jura Department of eastern France, in 1934. Ever since, it has been stored in the Museum National d’Histoire Naturelle, Paris. It was only briefly mentioned by scientists in studies in the 1930s and 1940s, but it was never recognised as a distinct species. It has largely been ignored in the literature, where it has often been referred to simply as the Damparis dinosaur.

Now, a deeper analysis of the fossil is also helping the scientists in today’s study to understand the environment Vouivria would have been in when it died, which was debated when it was initially found. The researchers believe Vouivria died in a coastal lagoon environment, during a brief sea level decline in Europe, before being buried when sea levels increased once more. When the fossil was first discovered, in rocks that would have originally come from a coastal environment, researchers suggested that its carcass had been washed out to sea, because sauropods were animals that lived on land.

Today’s team’s examination of Vouivria, coupled with an analysis of the rocks it was encased in, provides strong evidence that this was not the case.

The genus name of Vouivria is derived from the old French word ‘vouivre’, itself from the Latin ‘vipera’, meaning ‘viper’. In French-Comte, the region in which the specimen was originally discovered, ‘la vouivre’ is a legendary winged reptile. The species name damparisensis refers to the village Damparis, from which the fossil was originally found.

The research was carried out in conjunction with the Museum National d’Histoire Naturelle and the CNRS/Université Paris 1 Panthéon-Sorbonne, with funding from the European Union’s Synthesys programme.

Currently, titanosauriforms from the Late Cretaceous are poorly understood compared to their relatives in the Late Jurassic. So, the next step for the researchers will see them expanding on their analysis of the evolutionary relationships of all species in the titanosauriform group. The team are also aiming to find more sauropod remains from older rocks to determine in more detail how they spread across the continents.

Story Source:

Materials provided by Imperial College London. Note: Content may be edited for style and length.

Australia’s Jurassic Park’ the world’s most diverse

An unprecedented 21 different types of dinosaur tracks have been identified on a 25-kilometre stretch of the Dampier Peninsula coastline dubbed “Australia’s Jurassic Park.”

A team of palaeontologists from The University of Queensland’s School of Biological Sciences and James Cook University’s School of Earth and Environmental Sciences braved sharks, crocodiles, massive tides and the threat of development to unveil the most diverse assemblage of dinosaur tracks in the world in 127 to 140 million-year-old rocks in the remote Kimberley region of Western Australia.

Lead author Dr Steve Salisbury said the diversity of the tracks around Walmadany (James Price Point) was globally unparalleled and made the area the “Cretaceous equivalent of the Serengeti.”

“It is extremely significant, forming the primary record of non-avian dinosaurs in the western half the continent and providing the only glimpse of Australia’s dinosaur fauna during the first half of the Early Cretaceous Period,” Dr Salisbury said.

“It’s such a magical place — Australia’s own Jurassic Park, in a spectacular wilderness setting.”

In 2008, the Western Australian Government selected Walmadany as the preferred site for a $40 billion liquid natural gas processing precinct.

The area’s Traditional Custodians, the Goolarabooloo people, contacted Dr Salisbury and his team, who dedicated more than 400 hours to investigating and documenting the dinosaur tracks.

“We needed the world to see what was at stake,” Goolarabooloo Law Boss Phillip Roe said.

The dinosaur tracks form part of a song cycle that extends along the coast and then inland for 450 km, tracing the journey of a Dreamtime creator being called Marala, the Emu man.

“Marala was the Lawgiver. He gave country the rules we need to follow. How to behave, to keep things in balance,” Mr Roe said said.

“It’s great to work with UQ researchers. We learnt a lot from them and they learnt a lot from us.”

Dr Salisbury said the surrounding political issues made the project “particularly intense,” and he was relieved when National Heritage listing was granted to the area in 2011 and the gas project collapsed in 2013.

“There are thousands of tracks around Walmadany. Of these, 150 can confidently be assigned to 21 specific track types, representing four main groups of dinosaurs, ” Dr Salisbury said.

“There were five different types of predatory dinosaur tracks, at least six types of tracks from long-necked herbivorous sauropods, four types of tracks from two-legged herbivorous ornithopods, and six types of tracks from armoured dinosaurs.

“Among the tracks is the only confirmed evidence for stegosaurs in Australia. There are also some of the largest dinosaur tracks ever recorded. Some of the sauropod tracks are around 1.7 m long.”

“Most of Australia’s dinosaur fossils come from the eastern side of the continent, and are between 115 and 90 million years old. The tracks in Broome are considerably older.”

The research has been published as the 2016 Memoir of the Society of Vertebrate Paleontology.

Story Source:

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

Scientists make new discovery about bird evolution

In a new paper published in National Science Review, a team of scientists from the Institute of Vertebrate Paleontology and Paleoanthropology, the Shandong Tianyu Museum of Nature, and the Nanjing Institute of Geology and Paleontology (all in China) described the most exceptionally preserved fossil bird discovered to date.

The new specimen from the rich Early Cretaceous Jehol Biota (approximately 131 to 120 million years old) is referred to as Eoconfuciusornis, the oldest and most primitive member of the Confuciusornithiformes, a group of early birds characterized by the first occurrence of an avian beak. Its younger relative Confuciusornis is known from thousands of specimens but this is only the second specimen of Eoconfuciusornis found. This species comes only from the 130.7 Ma Huajiying Formation deposits in Hebei, which preserves the second oldest known fossil birds. Birds from this layer are very rare.

This new specimen of Eoconfuciusornis, housed in the Shandong Tianyu Museum of Nature, in Eastern China, is a female. The ovary reveals developing yolks that vary in size, similar to living birds. This suggests that confuciusornithiforms evolved a period of rapid yolk deposition prior to egg-laying (crocodilians, which are archosaurs like birds, deposit yolks slowly in all eggs for months with no period of rapid yolk formation), which is indicative of complex energetic profiles similar to those observed in birds.

This means Eoconfuciusornis and its kin, like living birds, was able to cope with extremely high metabolic demands during early growth and reproduction (whereas energetic demands in crocodiles are even, lacking complexity). In contrast, other Cretaceous birds including the more advanced group the Enantiornithes appear to have lower metabolic rates and have required less energy similar to crocodilians and non-avian dinosaurs (their developing yolks show little size disparity indicating no strong peak in energy associated with reproduction, and much simpler energetic profiles, limited by simpler physiologies).

Traces of skin indicate that the wing was supplemented by flaps of skin called patagia. Living birds have numerous wing patagia that help the bird to fly. This fossil helps show how bird wings evolved. The propatagium (the flap of skin that connects the shoulder and wrist) and postpatagium (the flap of skin that extends off the back of the hand and ulna) evolved before the alular patagium (the flap of skin connecting the first digit to the rest of the hand), which is absent in Eoconfuciusornis. Even more unique is the preservation of the internal structure of the propatagium which reveal a collagenous network identical to that in living birds. This internal network gives the skin flap its shape, allowing it to generate aerodynamic lift and aid the bird in flight.

The nearly complete plumage preserves remnants of the original plumage pattern, revealing the presence of spots on the wings and the earliest documentation of sexual differences in plumage within birds. This new specimen suggests that female Eoconfuciusornis were smaller than males and lacked tail feathers, similar to many sexually dimorphic living birds and the younger Confuciusornis in which the plumage of the males and females are different from each other. Samples of the feathers viewed under a microscope reveal differences in color characteristics, allowing scientists to reconstruct the plumage. Female Eoconfuciusornis had black spotted wings and gray body with a red throat patch.

Researchers have not found fossils from any other bird from the Jehol period that reveal so many types of soft tissue (feathers, skin, collagen, ovarian follicles). These remains allow researchers to create the most accurate reconstruction of a primitive early bird (or dinosaur) to date. This information provides better understanding of flight function in the primitive confuciusornithiforms and of the evolution of advanced flight features within birds.

“This new fossil is incredible,” said co-author Dr. Jingmai O’Connor. “With the amount of information we can glean from this specimen we can really bring this ancient species to life. We can understand how it grew, flew, reproduced, and what it looked like. Fossils like this one from the Jehol Biota continue to revolutionize our understanding of early birds.”

Story Source:

Materials provided by Oxford University Press USA. Note: Content may be edited for style and length.

Exceptionally preserved Jurassic sea life found in new fossil site

A trove of exceptionally preserved Jurassic marine fossils discovered in Canada, rare for recording soft-bodied species that normally don’t fossilize, is expanding scientists’ view of the rich marine life of the period.

The preservation of the fossils — which include soft body parts as well as shells and bones — ranks the site among the highest quality sources of Jurassic (183 million year old) marine fossils in the world, and the only such site in North America. A paper describing the site and fossils recovered from it was published online in the journal Geology in January.

The presence of fossilized soft tissue is especially significant because it offers a more complete view of life in ancient ecosystems and can help fill the gaps in knowledge connecting extinct organisms to those living today, said Rowan Martindale, a professor at The University of Texas at Austin’s Jackson School of Geosciences who led research on the fossils.

“In a normal fossil deposit, you only preserve a fraction of the organisms that were alive in the past. When you get an extraordinary fossil deposit with soft tissues preserved, you see significantly more of the community that would have been alive,” said Martindale, a paleontologist in the Department of Geological Sciences. “Normally, we wouldn’t find many of the animals because they lack a skeleton or have a very soft skeleton.”

Collaborators include researchers from Harvard University, Virginia Tech and Florida State University.

The new site was found on the Parks Canada Ya Ha Tinda Ranch near Banff National Park in southwest Alberta. Co-author Benjamin Gill, a professor at Virginia Tech, spotted the first exceptional fossil when he noticed his Ph.D. student and co-author, Theodore Them, standing right on top of a lobster.

“The lighting was just right to make out the outline of the lobster,” Gill said. “Then we looked around and noticed fossils all around us.”

The lobster was the first sign the site could be special because lobsters’ flexible exoskeletons usually aren’t preserved as fossils. Other unusual fossils recovered from the site include delicate shrimp, complete fish skeletons with scales and gills, large dolphin-like marine reptiles called ichthyosaurs, as well as “vampyropods” (related to modern vampire squid and octopus) with their delicate ink sacks still intact.

The presence of many well-preserved, soft-bodied animals marks the new site as a “Konservat-Lagerstätte,” a term for fossil beds that preserve an array of organisms with soft tissues as well as hard ones. These sites are rare. There are only three other sites, all located in Europe, that are known to contain fossils from the Early Jurassic like the Ya Ha Tinda site. Another famous example of a Canadian Lagerstätte is the Burgess Shale, which preserves a community of soft tissue organisms from the Cambrian Explosion (540 million years ago), named for the burst of animal diversity that appears in the fossil record from this time.

The new site is about 183 million years old, meaning the fossilized life was alive during the Early Jurassic. At this time, Ya Ha Tinda and the similarly aged European sites were on opposite sides of an ancient continent that became modern-day North America and parts of Europe. Having an array of well-preserved fossils from marine ecosystems on opposite sides of the continent will help scientists understand the distribution of sea life millions of years ago.

“This is the first time we have a site like this outside of Europe, so the Ya Ha Tinda fossilized community will give us a unique snapshot of life in the Early Jurassic Panthalassa Ocean,” Martindale said.

The researchers have been visiting the site every summer since 2013 and have recovered dozens of fossils, including some that are probably newly discovered species. Notable specimens include a lobster with bulky arms capped with diminutive, scissor-like claws, and 16 new vampyropod specimens, a number that Gill estimates increases known diversity of specimens from North America by threefold.

“Every time we’ve gone, we’ve found something new,” Gill said. “It’s a really abundant place.”

The next step of the research is to investigate how so many diverse organisms were fossilized together. Researchers think that the high-quality preservation is related to a widespread extinction of marine life caused by a period of extremely low levels of oxygen in parts of the Jurassic oceans. Free of most scavengers, these low oxygen areas could have been an ideal place for a carcass to lay undisturbed and become beautifully fossilized.

“If a carcass sinks into anoxic water, you’re more likely to get the conditions that will favor the preservation of soft tissues, feathers and articulated skeletons,” Martindale said. “These ‘fossil jackpots’ are really special.”

Story Source:

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