WFS News: Sollasina cthulhu, The ‘Monstrous’ ancient fossil

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Artist's reconstruction of Sollasina cthulhu ( Elissa Martin, Yale Peabody Museum of Natural History )

                  Artist’s reconstruction of Sollasina cthulhu ( Elissa Martin, Yale Peabody                                                                                   Museum of Natural History )

An incredibly well-preserved fossil unearthed in Herefordshire has been named after a hideous creature from fiction: Sollasina cthulhu.

Although no larger than 3cm wide, its array of tentacles reminded the team who discovered it of the monster Cthulhu created by American author H.P. Lovecraft. A gigantic entity worshipped by cultists, the writer describes its appearance is described as looking like an octopus, a dragon, and a caricature of human form.

The fossil meanwhile, is thought to be a relative of tube-shaped sea cucumbers and spiny sea urchins still alive today. Scientists from both Oxford University and University College London said their “monstrous” new discovery provides new insights into the evolution of this group.

After grinding away at layer after layer of rock, they were able to create a digital reconstruction of the soft body preserved for 430 million years.

“We carried out a number of analyses to work out whether Sollasina was more closely related to sea cucumbers or sea urchins. To our surprise, the results suggest it was an ancient sea cucumber,” said Dr Jeffrey Thompson. “This helps us understand the changes that occurred during the early evolution of the group, which ultimately gave rise to the slug-like forms we see today.”

Publishing their findings in the journal Proceedings of the Royal Society B, the scientists said that like its descendants that still crawl along the ocean floor today, their specimen would have used its tentacles to shift itself around and catch food.

The excellent preservation of the creature’s soft tissues even captured elements of the hydraulic system that this group of animals use to manoeuvre themselves around.

“Sollasina belongs to an extinct group called the ophiocistioids, and this new material provides the first information on the group’s internal structures,” said Dr Imran Rahman from the University of Oxford, who led the study. “This includes an inner ring-like form that has never been described in the group before. We interpret this as the first evidence of the soft parts of the water vascular system in ophiocistioids.”

Within this system, modern starfish, sea cucumbers and sea urchins have a system of canals connecting their numerous tube feet. They then move by contracting muscles and forcing water around the canals.

Source: Josh Gabbatiss,Science Correspondent,Independent.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News:The First Definite Lambeosaurine Bone From the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

The First Definite Lambeosaurine Bone From the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States

Scientific Reports volume 9, Article number: 5384 (2019)

Schematic drawing of differential habitat preference between hadrosaurines and lambeosaurines.

              Schematic drawing of differential habitat preference between hadrosaurines and                                                                                                 lambeosaurines.

The Prince Creek Formation of Alaska, a rock unit that represents lower coastal plain and delta deposits, is one of the most important formations in the world for understanding vertebrate ecology in the Arctic during the Cretaceous. Here we report on an isolated cranial material, supraoccipital, of a lambeosaurine hadrosaurid from the Liscomb Bonebed of the Prince Creek Formation. The lambeosaurine supraoccipital has well-developed squamosal bosses and a short sutural surface with the exoccipital-opisthotic complex, and is similar to lambeosaurine supraoccipitals from the Dinosaur Park Formation in having anteriorly positioned squamosal bosses. Affinities with Canadian lambeosaurines elucidate more extensive faunal exchange between the Arctic and lower paleolatitudes which was previously suggested by the presence of EdmontosaurusPachyrhinosaurus, tyrannosaurids, and troodontids in both regions. The presence of one lambeosaurine and nine hadrosaurine supraoccipitals in the Liscomb Bonebed suggests hadrosaurine dominated faunal structure as in the Careless Creek Quarry of the USA that was also deposited under a near-shore environment. It differs from the lambeosaurine dominant structures of localities in Russia and China interpreted as inland environments. This may suggest that lambeosaurines had less preference for near-shore environments than hadrosaurines in both Arctic and lower paleolatitudes.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Fossil site shows signs of meteor impact

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Sixty-six million years ago, a giant meteor slammed into Earth off the coast of modern-day Mexico. Firestorms incinerated the landscape for miles around. Even creatures thousands of miles away were doomed on that fateful day, if not by fire and brimstone, then by mega-earthquakes and waves of unimaginable size.

Now, scientists have unearthed a remarkable trove of fossils that appear to date from the very day of the impact. The burial site consists of more than four feet of sediments and organic remains that were dumped in North Dakota almost instantly and transformed into rock over the eons. It evidently captures, in unparalleled detail, the repercussions of the giant doomsday rock that cleared the way for the evolution of mammals, including the primates known as humans.

A tangled mass of articulated fish fossils uncovered in North Dakota. The site appears to date to the day 66 million years ago when a meteor hit Earth, killing nearly all life on the planet.CreditCreditRobert DePalma/University of Kansas

A tangled mass of articulated fish fossils uncovered in North Dakota. The site appears to date to the day 66 million years ago when a meteor hit Earth, killing nearly all life on the planet. Credit Robert DePalma/University of Kansas

In an article made available to reporters Friday in Proceedings of the National Academy of Sciences, a leading science journal, an international team of 12 scientists described a dig near Bowman, N.D., that encapsulated the swift demise of an ancient lake and its inhabitants.

When the meteor smashed into waters near what is now Mexico’s Yucatán Peninsula, it left a giant crater known as Chicxulub and prompted upheavals thousands of miles away, including what is now North Dakota. Within hours and perhaps minutes of the titanic collision, sea creatures were swept inland by tsunamis and earthquakes, tossed together and deposited with a diverse array of landlocked life, including trees, flowers and vanished types of freshwater fish.The jumble was swiftly entombed, and exquisitely preserved. Permeating the deposit were tiny spheres of clay and glass, known as tektites, which formed as molten rock, ejected by the impact, showered from the sky.

In the paper, the researchers argue that the fossil bed captures the Chicxulub impact’s immediate ramifications for life on Earth. It appears to be the best-ever snapshot of that day, one that advances the scientific understanding of “the full nature and extent of biotic disruptions that took place,” the authors write.

The lead researcher, Robert A. DePalma, is a curator of paleontology at the Palm Beach Museum of Natural History, in Florida, as well as a graduate student at the University of Kansas. Thirty-seven years old, he was granted access to the rich fossil bed by a rancher in 2012, then mined it secretly for years. His efforts are detailed in an article in The New Yorker that was posted online on Friday.

Gradually, Mr. DePalma shared his findings with top scientists, some of whom have now joined him as co-authors. They include Walter Alvarez, a geologist at the University of California, Berkeley, who pioneered the idea decades ago that the dinosaur extinction was the result of such a cosmic impact.

The paper describes how tektites, raining into the water, clogged the gills of fish, which were then killed by surges of water. The water could have traveled up from the Gulf of Mexico through an inland sea that cut through North America at the time. But the authors argue for another, more likely explanation: That cataclysmic waves from the impact — which produced the equivalent of a magnitude 10 or 11 earthquake — sloshed water out of distant lakes and seas and up their connected river channels.

“It basically agitates water like a washing machine,” said Phillip L. Manning, a paleontologist at the University of Manchester in England and one of the authors of the paper. “When that shock wave dissipates, it almost instantly drops out what was in this water body.”

Those contents, he said, formed the North Dakota deposit that he, Mr. DePalma and their colleagues described in their paper.

A partially exposed, perfectly preserved 66-million-year-old fish fossil uncovered by Mr. DePalma and his colleagues.CreditRobert DePalma/University of Kansas

A partially exposed, perfectly preserved 66-million-year-old fish fossil uncovered by Mr. DePalma and his colleagues.CreditRobert DePalma/University of Kansas

Mr. DePalma initially was disappointed with what he found, he said. He had hoped that the site would reveal rhythmic seasonal changes over a period of years. Instead, the material had been dumped in one big surge. “My idea of multi-season pond deposits was out the window,” he said.

In the deposit, the team discovered an ancient freshwater pond whose occupants had been quickly cemented together by waves of sediment and debris. The fossils include sturgeon and six-foot-long paddlefish, their scales intact but their bodies ripped and smashed; marine mollusks; leaves and tree fronds, and the burned trunks of trees. The fish carcasses were not bloated, decayed, or scavenged, suggesting that they were buried quickly — and that few animals were left alive after the cataclysm to come digging.

The fossil deposit also teems with tektites, tiny glass beads that are the telltale fallout of planetary-scale impacts. Fifty percent of the fossilized fish were found with tektites in their gills, as if the fish had inhaled the material. Also recovered were tektites trapped in amber. Their chemical composition was unchanged in 66 million years, and it closely matched the unique chemical signature of other tektites associated with the Chicxulub event.

The top layer of the fossil bed was found to be rich in iridium, a rare metal that Dr. Alvarez had originally identified at other sites as arising from the giant object that struck the Earth. Iridium, a precious metal belonging to the platinum group of elements, is more abundant in meteorites than in terrestrial rocks.

“Just the idea of fish with impact particles stuck in their gills from 66 million years ago, and trees with amber with impact particles, it’s so extraordinary that you do a double take for sure,” said Matthew Lamanna, a vertebrate paleontologist at the Carnegie Museum of Natural History in Pittsburgh, who was not involved with the research. “With the caveat that what they’re trying to show is really, really hard to show, I think they’ve done an excellent job of making that case.”

The Chicxulub impact and the global disaster it wrought are sometimes held up as the death stroke for the dinosaurs. But many scientists argue that an array of other factors, including volcanic eruptions and climatic disruptions, contributed to the demise of the giant reptiles.The article in The New Yorker describes information about the discovery site that goes well beyond what is found in the scientific paper. Mr. DePalma is quoted as having also found the remains of many dinosaurs in the deposit, implying that the North Dakota site might turn out to be the world’s first to clearly associate the cosmic blow to the end of the dinosaur age.

In an interview, Steve Brusatte, a vertebrate paleontologist and evolutionary biologist at the University of Edinburgh, called The New Yorker portrayal of the fossil find “a remarkable story” that he wanted to believe. “But it’s disappointing that the dinosaurs are not mentioned in the peer-reviewed paper,” he said. “And because they’re not, there simply isn’t any evidence for me to assess.”

For now, Dr. Brusatte said, “I am left with more questions than answers when it comes to the dinosaur aspect of this story.”

Mr. DePalma said the purpose of this first paper was to establish the geology and timing of what happened on that catastrophic day. Subsequent papers will go into more detail about the residents, including dinosaurs, that died, he said: “It wasn’t a paper about dinosaurs. This was a basic overview of the site and how it was formed.”

Source: Article by  William J. Broad and Kenneth Chang, New York times.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Fossil barnacles reveal prehistoric whale migrations

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Isotopes from fossil coronulid barnacle shells record evidence of migration

in multiple Pleistocene whale populations

Many whales take long journeys each year, spending summers feeding in cold waters and moving to warm tropical waters to breed. One theory suggests that these long-distance migrations originated around 5 million years ago, when ocean productivity became increasingly patchy. But patterns of ancient whale migrations have, until recently, been shrouded in mystery. Scientists from the Smithsonian Tropical Research Institute (STRI) and the University of California, Berkeley approached this question with an ingenious technique: barnacles.

“Instead of looking for clues to migration patterns from the whale’s bones, we used hitch-hiking whale barnacles instead,” said Larry Taylor, STRI visiting scientist and doctoral student at UC Berkeley who led the study.

Barnacles are crustaceans (crabs, lobsters, shrimp) that live stuck in one place in a hard shell. Most glue themselves to rocks, but whale barnacles attach to a whale’s skin by sucking the skin in.

Fossil whale barnacles from the Pleistocene were retrieved from the Burica Peninsula of Panama for analyses. Credit: Larry Taylor

Fossil whale barnacles from the Pleistocene were retrieved from the Burica Peninsula of Panama for analyses. Credit: Larry Taylor

“Whale barnacles are usually species specific — one species of barnacle on one type of whale,” said Aaron O’Dea, staff scientist at STRI and co-author of the study. “This gives the barnacle several advantages — a safe surface to live on, a free ride to some of the richest waters in the world and a chance to meet up with others when the whales get together to mate.”

As whale barnacles grow, their shells record the conditions by taking up oxygen isotopes from the water. By carefully reading the unique isotope signatures left in the shells, the barnacles can reveal the water bodies the barnacle passed through, helping reconstruct the whale’s movements over time.

The study, published in Proceedings of the National Academy of Sciences looked at a number of fossil and modern whale barnacles from the Pacific coast of Panama and California.

“The signals we found in the fossil barnacles showed us quite clearly that ancient humpback and grey whales were undertaking journeys very similar to those that these whales make today,” Taylor said. “It seems like the summer-breeding and winter-feeding migrations have been an integral part of the way of life of these whales for hundreds of thousands of years.”

“We want to push the technique further back in time and across different whale populations,” said Seth Finnegan, co-author from UC Berkeley. “Hunting for fossil whale barnacles is easier than whales, and they provide a wealth of information waiting to be uncovered.”

Journal Reference:

  1. Larry D. Taylor, Aaron O’Dea, Timothy J. Bralower, Seth Finnegan. Isotopes from fossil coronulid barnacle shells record evidence of migration in multiple Pleistocene whale populationsProceedings of the National Academy of Sciences, 2019; 201808759 DOI: 10.1073/pnas.1808759116
  2. Smithsonian Tropical Research Institute. “Deep time tracking devices: Fossil barnacles reveal prehistoric whale migrations.” ScienceDaily. ScienceDaily, 25 March 2019. <www.sciencedaily.com/releases/2019/03/190325163019.htm>.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Surprise beach find adds missing piece to fossil record

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

A beach can be a place of discovery. Broken shells, whimsical weathered bits of wood, flotsam from a foreign corner of the globe. You never know what treasure you might find.

Tapir Fossil at the Museum of the North (KTUU)

                            Tapir Fossil at the Museum of the North (KTUU)

In July of 2017, the Reising family of Seward, Alaska was enjoying a picnic lunch on a popular beach near Homer, Alaska, taking a break from a favorite hobby, beachcombing.

“We were looking for plant fossils,” said Kai Reising. He was five years old at the time and running late for lunch. As he joined the rest of his family, he spotted a rock almost under his Dad’s feet. “It looked like a piece of petrified wood and I picked it up,” he recalled.

It was a bread loaf-sized piece of brown sandstone. Kai thought it was interesting, so he passed it to his dad for a second opinion. George Reising, Kai’s father, is a science and math teacher at Seward High School. “We flipped it over and right on the bottom were all these teeth,” George Reising said.

Kai’s mom, Deb Klien, is a biologist. She homeschools Kai and his younger brother Silas. “We just had a lot of fun speculating on what it might be,” she said. That’s when everyone got excited– making guesses as to what type of animal Kai’s find might be.

On their way home to Seward, they stopped by a rock shop in Sterling, Alaska for an additional opinion. It was pointed out that there was coal present in the sandstone. That’s when George Reising knew what they had found was about 10 million years old. “All of our lights went on. And we said, wait a minute, this is not Pleistocene at all. This is something significant. Nothing in the record,” George Reising said.

Dr. Patrick Druckenmiller, Director of the University of Alaska Museum of the North in Fairbanks, explains why there would be something new to Alaska’s fossil record. “We have dinosaur fossils in Alaska up to about 69-70 million years ago. And we have ice age mammal fossils in Alaska about just several thousand years old. And in between is a big gap that we have almost nothing in terms of fossil vertebrates.”

The Reisings had met Druckenmiller on a trip to Fairbanks they made earlier in the year. So they sent him some pictures of the fossil. When he saw the pictures, his heart rate went up. “This was something we had never seen before,” Druckenmiller said. A hand-off of the rock was arranged and a basic identification of what had been found quickly followed. “These teeth are very distinctly Tapir Teeth,” Druckenmiller said.

Tapirs can still be found in some parts of South America but they are a fraction of the size of their fossilized cousin. “This is the first evidence of this group of animals ever found in the state of Alaska,” Druckenmiller said. He thinks it is possible this might even be a new species.

A dark spot on the fossil offers an important clue to Druckenmiller. “It is very clearly a fresh break and this is probably right where this was attached to more of the skull in the side of the hill before it weathered out and tumbled down the bluff.”

That speculation prompted a trip back to the Homer beach this past summer. Hopes were high of finding additional pieces of the Tapir. But a group of scientists couldn’t duplicate the luck of a 5-year-old boy and no other pieces were found.

Druckenmiller wasn’t surprised this important fossil was found by a family on a picnic. “A lot of major fossil finds, whether they be dinosaurs or mammals or whatever, they’re not made by professional paleontologists,” he said. “They’re made by people out walking on the beach or out hunting or out fishing… because they are out in a place people don’t normally go.”

Also, he adds, “Five-year-olds are a lot closer to the ground.”

Druckenmiller wants to remind people that fossils found on state land are property of the state. He says, if you find something interesting, you can help by taking lots of pictures of the find and of the area. And if possible, note the GPS coordinates.

Source: www.ktuu.com

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

 

WFS News: Oldest Frog Relative from North America

@ WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

It’s possible that during the Triassic period, the crocodile-like phytosaur snapped at a frog-like creature, but missed. It’s a good thing it did, because 216 million years later, paleontologists have found the fossils of these tiny creatures, the oldest known frog relative from North America, a new study finds.

This frog — nicknamed the Chinle frog because it was found in the Chinle Formation of northern Arizona — is a big finding, but the creature itself was small, just over 0.5 inches (1.3 centimeters) long.

“The Chinle frog could fit on the end of your finger,” study lead researcher Michelle Stocker, an assistant professor of geosciences at Virginia Tech, said in a statement.

An artist’s interpretation of the newly discovered Chinle frog that’s dangling from the jaw of a phytosaur, a heavily armoured semi-aquatic reptile.Credit: Andrey Atuchin/Virginia Tech

The frog fossils were found next to the fossils of the crocodile-like phytosaur and those of early dinosaurs, the researchers said. The scientists, however, didn’t find entire frog skeletons, but rather a few fragmented ilium, or hip bones, from several of these ancient frogs during an excavation in May 2018. But they hope to find more of the frogs’ fossils soon, which is why they haven’t given the creature a scientific name yet.

They are still sifting through the dirt and rock excavated at the site, where they expect to find more skull and skeletal material from the frogs — findings they say will be more informative about the identity of this kind of creature, Stocker said.

The team noted that while Chinle specimens are distant relatives of frogs, they are not the direct ancestor of modern frogs. But they’re still salientians — a group that includes living frogs and their closely related, extinct relatives.

In fact, the Chinle frog is the oldest known salientian from near the equator, the researchers noted.

That’s because during the Triassic period, when these frog-like animals lived, Arizona wasn’t where it is today. Instead, the Grand Canyon state was once part of the supercontinent Pangaea and was located about 10 degrees north of the equator, the researchers said.

An analysis of the frogs’ hip bones shows that the species shares more features with modern frogs and Prosalirus, an early Jurassic frog discovered in the present-day Navajo Nation, than it does with Triadobatrachus, an early Triassic frog found in modern-day Madagascar.

“These are the oldest frogs from near the equator,” Stocker said. “The oldest frogs overall are roughly 250 million years old from Madagascarand Poland, but those specimens are from higher latitudes [than the Chinle frog] and not equatorial.”

The discovery of the Chinle frog may also be a sign of things to come. “Now [that] we know that tiny frogs were present approximately 215 million years ago from North America, we may be able to find other members of the modern vertebrate communities in the Triassic period,” study co-researcher Sterling Nesbitt, an assistant professor of geosciences at Virginia Tech, said in the statement.

The study was published online today (Feb. 27) in the journal Biology Letters.

Source: article by  Laura Geggel, Associate Editor, livescience.com

@ WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Computer simulations on swimming of Ichthyosaurs

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Using computer simulations and 3D models, palaeontologists from the University of Bristol have uncovered more detail on how Mesozoic sea dragons swam.

The research, published today in the journal Proceedings of the Royal Society B, sheds new light on their energy demands while swimming, showing that even the first ichthyosaurs had body shapes well adapted to minimise resistance and maximise volume, in a similar way to modern dolphins.

Digital models of the ichthyosaurs analysed in this study shown in their phylogenetic context. Simplified phylogeny

Digital models of the ichthyosaurs analysed in this study shown in their phylogenetic context. Simplified phylogeny

Ichthyosaurs are an extinct group of sea-going reptiles that lived during the Mesozoic Era, around 248-93.9 million years ago.

During their evolution, they changed shape substantially, from having narrow, lizard-like bodies to more streamlined fish-shaped bodies.

It was assumed that the change in body shape made them more efficient swimmers, especially by reducing the drag of the body, in other words, the resistance to movement.

Drag coefficients of nine ichthyosaurs and a modern analogue, the bottlenose dolphin. (a,b) CFD-computed total drag coefficients of nine ichthyosaurs and a bottlenose dolphin without (a) and with (b) limbs at Reynolds numbers from 106 to 5 × 107. (c,d) Comparison of the drag coefficients and their mean values (in grey) between taxa, without (c) and with (d) limbs; two-sample t-tests between groups not significant (NS). (e,f) Mean values of the drag coefficient of ichthyosaurs plotted against the mean occurrence age for each taxon, without (e) and with (f) fins; no correlation detected, Kendall's τ = −0.29, p = 0.28, NS (no limbs); Kendall's τ = −0.22, p = 0.39, NS (with limbs). Ichthyosaurs from the ‘basal grade’ are highlighted in yellow, the ‘intermediate grade’ in green and the ‘fish-shaped ichthyosaurs' in blue. The bottlenose dolphin Tursiops is highlighted in red. (g) Two-dimensional plots of flow velocity magnitude (Re = 5 × 106; inlet velocity of 5 m s−1).

Drag coefficients of nine ichthyosaurs and a modern analogue, the bottlenose dolphin. (a,b) CFD-computed total drag coefficients of nine ichthyosaurs and a bottlenose dolphin without (a) and with (b) limbs at Reynolds numbers from 106 to 5 × 107. (c,d) Comparison of the drag coefficients and their mean values (in grey) between taxa, without (c) and with (d) limbs; two-sample t-tests between groups not significant (NS). (e,f) Mean values of the drag coefficient of ichthyosaurs plotted against the mean occurrence age for each taxon, without (e) and with (f) fins; no correlation detected, Kendall’s τ = −0.29, p = 0.28, NS (no limbs); Kendall’s τ = −0.22, p = 0.39, NS (with limbs). Ichthyosaurs from the ‘basal grade’ are highlighted in yellow, the ‘intermediate grade’ in green and the ‘fish-shaped ichthyosaurs’ in blue. The bottlenose dolphin Tursiops is highlighted in red. (g) Two-dimensional plots of flow velocity magnitude (Re = 5 × 106; inlet velocity of 5 m s−1).

If they could produce less resistance for a given body mass, they would have more power for swimming, or swimming would take less effort. Then they could swim longer distances or reach faster speeds.

Susana Gutarra, a PhD student in palaeobiology at the University of Bristol’s School of Earth Sciences, said: “To test whether fish-shaped bodies helped ichthyosaurs reduce the energy demands of swimming, we made 3D models of several different ichthyosaurs.

“We also created a model of a bottlenose dolphin, a living species which can be observed in the wild, so we could test if the method worked.”

Dr Colin Palmer, a hydrodynamics expert and a collaborator, added: “Susana used classic methods from ship design to test these ancient reptiles.

“The software builds a “virtual water tank” where we can control variables like the temperature, density and speed or water, and that allow us to measure all resulting forces.

“The model ichthyosaurs were put into this “tank,” and fluid flow conditions modelled, in the same way ship designers test different hull shapes to minimize drag and improve performance.”

Professor Mike Benton, also from Bristol’s School of Earth Sciences and a collaborator, said: “Much to our surprise, we found that the drastic changes to ichthyosaur body shape through millions of years did not really reduce drag very much.

“All of them had low-drag designs, and body shape must have changed from long and slender to dolphin-like for another reason. It seems that body size mattered as well.”

Susana Gutarra added: “The first ichthyosaurs were quite small, about the size of an otter, and later ones reached sizes of 5-20 metres in length.

“When we measured flow over different body shapes at different sizes, we found that large bodies reduced the mass-specific energy demands of steady swimming.”

Dr Benjamin Moon, another collaborator from Bristol’s School of Earth Sciences, said: “There was a shift in swimming style during ichthyosaur evolution. The most primitive ichthyosaurs swam by body undulations and later on they acquired broad tails for swimming by beating their tails (more efficient for fast and sustained swimming).

However, we found that some very early ichthyosaurs, like Utatsusaurus, might have been well suited for endurance swimming thanks to their large size, in spite of swimming by body undulations. Our results provide a very interesting insight into the ecology of ichthyosaurs.”

Susana Gutarra concluded: “Swimming is a very complex phenomenon and there are some aspects of it that are particularly hard to test in fossil animals, like motion.

“In the future, we’ll probably see simulations of ichthyosaurs moving through water.

“At the moment, simulating the ichthyosaurs in a static gliding position, enables us to focus our study on the morphology, minimizing our assumptions about their motion and also allow us to compare a relatively large sample of models.”

Comparison of the effects of body shape, swimming style and body size on the net energy cost of steady swimming in ichthyosaurs. (a,b) Relative net cost of steady swimming (COTnet) for ichthyosaurs of the same mass moving at the same speed. (a) Differences owing to morphology, not accounting for swimming style (propulsive efficiency, η = 1). (b) Differences owing to body shape and swimming style, incorporating propulsive efficiency estimates from living aquatic vertebrates; η = 0.48 for anguilliform swimmers [31] and η = 0.81 for carangiform swimmers [28,29]. (c,d) Relative differences in the net cost of swimming owing to body shape and size (length for each taxon is the mean of multiple specimens), moving at the same speed of 1 m s−1, when swimming efficiency is not accounted for (η = 1) (c), or (d) after incorporating the propulsive efficiency as in (b). (e) Mean COTnet of ichthyosaurs at life-size scale calculated as in (d), plotted against the mean occurrence age for each taxon. Colour coding for (a–e) corresponds to the one used in figures 2 and 3.

Comparison of the effects of body shape, swimming style and body size on the net energy cost of steady swimming in ichthyosaurs. (a,b) Relative net cost of steady swimming (COTnet) for ichthyosaurs of the same mass moving at the same speed. (a) Differences owing to morphology, not accounting for swimming style (propulsive efficiency, η = 1). (b) Differences owing to body shape and swimming style, incorporating propulsive efficiency estimates from living aquatic vertebrates; η = 0.48 for anguilliform swimmers [31] and η = 0.81 for carangiform swimmers [28,29]. (c,d) Relative differences in the net cost of swimming owing to body shape and size (length for each taxon is the mean of multiple specimens), moving at the same speed of 1 m s−1, when swimming efficiency is not accounted for (η = 1) (c), or (d) after incorporating the propulsive efficiency as in (b). (e) Mean COTnet of ichthyosaurs at life-size scale calculated as in (d), plotted against the mean occurrence age for each taxon. Colour coding for (a–e) corresponds to the one used in figures 2 and 3.

This research was funded by the Natural Environment Research Council, UK.

Journal Reference:Susana Gutarra, Benjamin C. Moon, Imran A. Rahman, Colin Palmer, Stephan Lautenschlager, Alison J. Brimacombe, Michael J. Benton. Effects of body plan evolution on the hydrodynamic drag and energy requirements of swimming in ichthyosaursProceedings of the Royal Society B: Biological Sciences, 2019; 286 (1898): 20182786 DOI: 10.1098/rspb.2018.2786

University of Bristol. “Scientists put ichthyosaurs in virtual water tanks.” ScienceDaily. ScienceDaily, 6 March 2019. <www.sciencedaily.com/releases/2019/03/190306081714.htm>.
@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Origins of giant extinct New Zealand bird adzebill traced to Africa

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Adzebill skeleton on display in the Canterbury Museum, New Zealand. Among the giant bird's closest living relatives are the tiny flufftails from Madagascar and Africa. Credit: Canterbury Museum

Adzebill skeleton on display in the Canterbury Museum, New Zealand. Among the giant bird’s closest living relatives are the tiny flufftails from Madagascar and Africa.Credit: Canterbury Museum

Scientists have revealed the African origins of New Zealand’s most mysterious giant flightless bird — the now extinct adzebill — showing that some of its closest living relatives are the pint-sized flufftails from Madagascar and Africa.

Led by the University of Adelaide, the research in the journal Diversity showed that among the closest living relatives of the New Zealand adzebills — which weighed up to 19 kilograms — are the tiny flufftails, which can weigh as little as 25 grams. The closeness of the relationship strongly suggests that the ancestors of the adzebills flew to New Zealand after it became physically isolated from other land.

This finding mirrors the close relationship between New Zealand’s kiwi and the extinct Madagascan elephant birds, published by University of Adelaide researchers in 2014, hinting at an unappreciated biological connection between Madagascar and New Zealand.

Like the better-known moa, the two species of adzebill — the North Island adzebill and South Island adzebill -disappeared following the arrival of early Maori in New Zealand, who hunted them and cleared their forest habitats. Unlike the moa, adzebills were predators and not herbivores.

“The adzebill were almost completely wingless and had an enormous reinforced skull and beak, almost like an axe, which is where they got their English name,” says Alexander Boast, lead author and former Masters student at the University of Adelaide.

“If they hadn’t gone extinct, they would be among the largest living birds.”

A team of researchers from Australia, New Zealand, and the US analysed genetic data from the two adzebill species.

“A lot of past genetic research and publicity has focused on the moa, which we know were distant relatives of the ostrich, emu, and cassowary,” says co-author Dr Kieren Mitchell, postdoctoral researcher at the University of Adelaide.

“But noone had analysed the genetics of the adzebill, despite a lot of debate about exactly what they were and where they came from.”

“We know that adzebills have been in New Zealand for a relatively long time, since we previously discovered a 19 million-year-old adzebill fossil on the South Island,” says co-author Associate Professor Trevor Worthy, a palaeontologist at Flinders University.

“A key question is whether they’ve been present since New Zealand broke away from the other fragments of the supercontinent Gondwana or whether their ancestors flew to New Zealand from elsewhere later on.”

Researchers at both the University of Adelaide’s Australian Centre for Ancient DNA and Curtin University’s Ancient DNA Lab sequenced adzebill DNA from fragments of bone and eggshell. They compared this to DNA from living birds to discover the identity and origin of the adzebill.

“It’s possible that ancient migration of birds between Madagascar and New Zealand may have occurred via Antarctica,” says Dr Mitchell.

“Some coastal regions of the continent remained forested and ice free until as recently as 30 million years ago.”

Dr Paul Scofield, Senior Curator Natural History at Canterbury Museum says: “The North Island adzebill likely evolved from its South Island counterpart relatively recently. We know the North and South Islands were joined by a narrow piece of land around two million years ago. Adzebills probably developed in the South Island, then walked over this land bridge to the North Island.”

  1. alexander P. Boast, Brendan Chapman , Michael B. Herrera, Trevor H. Worthy, R. Paul Scofield, Alan J. D. Tennyson, Peter Houde, Michael Bunce, Alan Cooper and Kieren J. Mitchell. Mitochondrial Genomes from New Zealand’s Extinct Adzebills (Aves: Aptornithidae: Aptornis) Support a Sister-Taxon Relationship with the Afro-Madagascan SarothruridaeDiversity, 2019 DOI: 10.3390/d11020024  
University of Adelaide. “Origins of giant extinct New Zealand bird traced to Africa.” ScienceDaily. ScienceDaily, 21 February 2019. <www.sciencedaily.com/releases/2019/02/190221110359.htm>.
@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Prehistoric worms populated the sea bed 500 million years ago

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Prehistoric worms populated the sea bed 500 million years ago — evidence that life was active in an environment thought uninhabitable until now, research by the University of Saskatchewan (USask) shows.

The sea bed in the deep ocean during the Cambrian period was thought to have been inhospitable to animal life because it lacked enough oxygen to sustain it.

But research published in the scientific journal Geology reveals the existence of fossilized worm tunnels dating back to the Cambrian period — 270 million years before the evolution of dinosaurs.

These are worm tunnels (labelled) visible in small section of rock. Credit: Professor Brian Pratt, University of Saskatchewan

These are worm tunnels (labelled) visible in small section of rock.
Credit: Professor Brian Pratt, University of Saskatchewan

The discovery, by USask professor Brian Pratt, suggests that animal life in the sediment at that time was more widespread than previously thought.

The worm tunnels — borrows where worms lived and munched through the sediment — are invisible to the naked eye. But Pratt “had a hunch” and sliced the rocks and scanned them to see whether they revealed signs of ancient life.

The rocks came from an area in the remote Mackenzie Mountains of the Northwest Territories in Canada which Pratt found 35 years ago.

Pratt then digitally enhanced images of the rock surfaces so he could examine them more closely. Only then did the hidden ‘superhighway’ of burrows made by several different sizes and types of prehistoric worm emerge in the rock.

Some were barely a millimetre in size and others as large as a finger. The smaller ones were probably made by simple polychaetes — or bristle worms — but one of the large forms was a predator that attacked unsuspecting arthropods and surface-dwelling worms.

Pratt said he was “surprised” by the unexpected discovery.

“For the first time, we saw evidence of large populations of worms living in the sediment — which was thought to be barren,” he said. “There were cryptic worm tunnels — burrows — in the mud on the continental shelf 500 million years ago, and more animals reworking, or bioturbating, the sea bed than anyone ever thought.”

Pratt, a geologist and paleontologist and Fellow of the Geological Society of America, found the tunnels in sedimentary rocks that are similar to the Burgess Shale, a famous fossil-bearing deposit in the Canadian Rockies.

The discovery may prompt a rethink of the level of oxygenation in ancient oceans and continental shelves.

The Cambrian period saw an explosion of life on Earth in the oceans and the development of multi-cellular organisms including prehistoric worms, clams, snails and ancestors of crabs and lobsters. Previously the seas had been inhabited by simple, single-celled microbes and algae.

It has always been assumed that the creatures in the Burgess Shale — known for the richness of its fossils — had been preserved so immaculately because the lack of oxygen at the bottom of the sea stopped decay, and because no animals lived in the mud to eat the carcasses.

Pratt’s discovery, with co-author Julien Kimmig, now of the University of Kansas, shows there was enough oxygen to sustain various kinds of worms in the sea bed.

“Serendipity is a common aspect to my kind of research,” Pratt said. “I found these unusual rocks quite by accident all those years ago. On a hunch I prepared a bunch of samples and when I enhanced the images I was genuinely surprised by what I found,” he said.

“This has a lot of implications which will now need to be investigated, not just in Cambrian shales but in younger rocks as well. People should try the same technique to see if it reveals signs of life in their samples.”

The research was funded by the Natural Sciences and Engineering Research Council of Canada.

  1. Brian R. Pratt, Julien Kimmig. Extensive bioturbation in a middle Cambrian Burgess Shale–type fossil Lagerstätte in northwestern CanadaGeology, 2019; 47 (3): 231 DOI: 10.1130/G45551.1

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Source: www.sciencedaily.com/releases/2019/02/190228113640.htm

WFS News:Plant leaf tooth feature extraction

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Plant leaf tooth feature extraction

Citation: Wang H, Tian D, Li C, Tian Y, Zhou H (2019) Plant leaf tooth feature extraction. PLoS ONE 14(2): e0204714. https://doi.org/10.1371/journal.pone.0204714

Editor: Yi Jiang, Georgia State University, UNITED STATES

The eight types of leaves. https://doi.org/10.1371/journal.pone.0204714.g004

The eight types of leaves.https://doi.org/10.1371/journal.pone.0204714.g004

Leaf tooth can indicate several systematically informative features and is extremely useful for circumscribing fossil leaf taxa. Moreover, it can help discriminate species or even higher taxa accurately. Previous studies extract features that are not strictly defined in botany; therefore, a uniform standard to compare the accuracies of various feature extraction methods cannot be used. For efficient and automatic retrieval of plant leaves from a leaf database, in this study, we propose an image-based description and measurement of leaf teeth by referring to the leaf structure classification system in botany. First, image preprocessing is carried out to obtain a binary map of plant leaves. Then, corner detection based on the curvature scale-space (CSS) algorithm is used to extract the inflection point from the edges; next, the leaf tooth apex is extracted by screening the convex points; then, according to the definition of the leaf structure, the characteristics of the leaf teeth are described and measured in terms of number of orders of teeth, tooth spacing, number of teeth, sinus shape, and tooth shape. In this manner, data extracted from the algorithm can not only be used to classify plants, but also provide scientific and standardized data to understand the history of plant evolution. Finally, to verify the effectiveness of the extraction method, we used simple linear discriminant analysis and multiclass support vector machine to classify leaves. The results show that the proposed method achieves high accuracy that is superior to that of other methods.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev