Dinosaurs could get cancer


This 4 August 2020 video, in Indonesian, is about the recent discovery that a Centrosaurus dinosaur had bone cancer.

Translated from Dutch NOS radio today:

Canadian scientists have for the first time found evidence that dinosaurs could also develop bone cancer.

Paleontologists discovered this when they re-examined malformations on the fossil of a Centrosaurus – a horned, herbivorous dinosaur that lived in the Cretaceous period more than 70 million years ago.

The fossil was excavated in the Canadian province of Alberta in 1989 and was notable for a fibula defect, which was then assessed by scientists as a healed fracture. New research with detailed CT scans found it likely to be an aggressive form of bone cancer.

The tumor was the size of an apple, the scientists said in an article in the scientific journal Lancet Oncology.

Triassic dinosaurs family tree, new research


This 2016 video says about itself:

Triassic Age Of Dinosaur – AMAZING DINOSAURS DOCUMENTARY

Dinosaurs are a diverse group of animals of the clade Dinosauria. They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the start of the Jurassic (about 200 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups at the end of the Mesozoic Era.

The fossil record indicates that birds are modern feathered dinosaurs, having evolved from theropod ancestors during the Jurassic Period. Birds were the only dinosaurs to survive the extinction event that occurred 66 million years ago.

From the Massachusetts Institute of Technology in the USA:

Study sheds light on the evolution of the earliest dinosaurs

Geological evidence suggests the known dinosaur groups diverged early on, supporting the traditional dinosaur family tree

July 29, 2020

Summary: Geological evidence suggests the known dinosaur groups diverged early on, supporting the traditional dinosaur family tree.

The classic dinosaur family tree has two subdivisions of early dinosaurs at its base: the Ornithischians, or bird-hipped dinosaurs, which include the later Triceratops and Stegosaurus; and the Saurischians, or lizard-hipped dinosaurs, such as Brontosaurus and Tyrannosaurus.

In 2017, however, this classical view of dinosaur evolution was thrown into question with evidence that perhaps the lizard-hipped dinosaurs evolved first — a finding that dramatically rearranged the first major branches of the dinosaur family tree.

Now an MIT geochronologist, along with paleontologists from Argentina and Brazil, has found evidence to support the classical view of dinosaur evolution. The team’s findings are published today in the journal Scientific Reports.

The team reanalyzed fossils of Pisanosaurus, a small bipedal dinosaur that is thought to be the earliest preserved Ornithiscian in the fossil record. The researchers determined that the bird-hipped herbivore dates back to 229 million years ago, which is also around the time that the earliest lizard-hipped Saurischians are thought to have appeared.

The new timing suggests that Ornithiscians and Saurischians first appeared and diverged from a common ancestor at roughly the same time, giving support to the classical view of dinosaur evolution.

The researchers also dated rocks from the Ischigualasto Formation, a layered sedimentary rock unit in Argentina that is known for having preserved an abundance of fossils of the very earliest dinosaurs. Based on these fossils and others across South America, scientists believe that dinosaurs first appeared in the southern continent, which at the time was fused together with the supercontinent of Pangaea. The early dinosaurs are then thought to have diverged and fanned out across the world.

However, in the new study, the researchers determined that the period over which the Ischigualasto Formation was deposited overlaps with the timing of another important geological deposit in North America, known as the Chinle Formation.

The middle layers of the Chinle Formation in the southwestern U.S. contain fossils of various fauna, including dinosaurs that appear to be more evolved than the earliest dinosaurs. The bottom layers of this formation, however, lack animal fossil evidence of any kind, let alone early dinosaurs. This suggests that conditions within this geological window prevented the preservation of any form of life, including early dinosaurs, if they walked this particular region of the world.

“If the Chinle and Ischigualasto formations overlap in time, then early dinosaurs may not have first evolved in South America, but may have also been roaming North America around the same time,” says Jahandar Ramezani, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences, who co-authored the study. “Those northern cousins just may not have been preserved.”

The other researchers on the study are first author Julia Desojo from the National University of La Plata Museum, and a team of paleontologists from institutions across Argentina and Brazil.

“Following footsteps”

The earliest dinosaur fossils found in the Ischigualasto Formation are concentrated within what is now a protected provincial park known as “Valley of the Moon” in the San Juan Province. The geological formation also extends beyond the park, albeit with fewer fossils of early dinosaurs. Ramezani and his colleagues instead looked to study one of the accessible outcrops of the same rocks, outside of the park.

They focused on Hoyada del Cerro Las Lajas, a less-studied outcrop of the Ischigualasto Formation, in La Rioja Province, which another team of paleontologists explored in the 1960s.

“Our group got our hands on some of the field notes and excavated fossils from those early paleontologists, and thought we should follow their footsteps to see what we could learn,” Desojo says.

Over four expeditions between 2013 to 2019, the team collected fossils and rocks from various layers of the Las Lajas outcrop, including more than 100 new fossil specimens, though none of these fossils were of dinosaurs. Nevertheless, they analyzed the fossils and found they were comparable, in both species and relative age, to nondinosaur fossils found in the park region of the same Ischigualasto Formation. They also found out that the Ischigualasto Formation in Las Lajas was significantly thicker and much more complete than the outcrops in the park. This gave them confidence that the geological layers in both locations were deposited during the same critical time interval.

Ramezani then analyzed samples of volcanic ash collected from several layers of the Las Lajas outcrops. Volcanic ash contains zircon, a mineral that he separated from the rest of the sediment, and measured for isotopes of uranium and lead, the ratios of which yield the mineral’s age.

With this high-precision technique, Ramezani dated samples from the top and bottom of the outcrop, and found that the sedimentary layers, and any fossils preserved within them, were deposited between 230 million and 221 million years ago. Since the team determined that the layered rocks in Las Lajas and the park match in both species and relative timing, they could also now determine the exact age of the park’s more fossil-rich outcrops.

Moreover, this window overlaps significantly with the time interval over which sediments were deposited, thousands of kilometers northward, in the Chinle Formation.

“For many years, people thought Chinle and Ischigualasto formations didn’t overlap, and based on that assumption, they developed a model of diachronous evolution, meaning the earliest dinosaurs appeared in South America first, then spread out to other parts of the world including North America,” Ramezani says. “We’ve now studied both formations extensively, and shown that diachronous evolution isn’t really based on sound geology.”

A family tree, preserved

Decades before Ramezani and his colleagues set out for Las Lajas, other paleontologists had explored the region and unearthed numerous fossils, including remains of Pisanosaurus mertii, a small, light-framed, ground-dwelling herbivore. The fossils are now preserved in an Argentinian museum, and scientists have gone back and forth on whether it is a true dinosaur belonging to the Ornithiscian group, or a ” basal dinosauromorph” — a kind of pre-dinosaur, with features that are almost, but not quite fully, dinosaurian.

“The dinosaurs we see in the Jurassic and Cretaceous are highly evolved, and ones we can nicely identify, but in the late Triassic, they all looked very much alike, so it’s very hard to distinguish them from each other, and from basal dinosauromorphs,” Ramezani explains.

His collaborator Max Langer from the University of São Paulo in Brazil painstakingly reanalyzed the museum-preserved fossil of Pisanosaurus, and concluded, based on certain key anatomical features, that it is indeed a dinosaur — and what’s more, that it is the earliest preserved Ornithiscian specimen. Based on Ramezani’s dating of the outcrop and the interpretation of Pisanosaurus, the researchers concluded that the earliest bird-hipped dinosaurs appeared around 229 million years ago — around the same time as their lizard-hipped counterparts.

“We can now say the earliest Ornithiscians first showed up in the fossil record roughly around the same time as the Saurischians, so we shouldn’t throw away the conventional family tree,” Ramezani says. “There are all these debates about where dinosaurs appeared, how they diversified, what the family tree looked like. A lot of those questions are tied to geochronology, so we need really good, robust age constraints to help answer these questions.”

This research was mainly funded by the National Council for Scientific and Technical Research (Argentina) and the São Paulo State Research Support Foundation (Brazil). Geochronologic research at the MIT Isotope Lab has been supported in part by the U.S. National Science Foundation.

Young dinosaur jawbone discovery in Alaska


This January 2019 video from the Milwaukee Public Museum in the USA says about itself:

MPM Untold – The Dromaeosaur

T.rex has a new friend in the Hell Creek exhibit. Want to meet him? Watch MPM Untold and find out what’s been updated!

From PLOS:

Fossil jawbone from Alaska is a rare case of a juvenile Arctic dromaeosaurid dinosaur

This fossil is a clue to the history of how dinosaurs dispersed between continents, showing some dinosaurs likely nested in the far north

July 8, 2020

A small piece of fossil jawbone from Alaska represents a rare example of juvenile dromaeosaurid dinosaur remains from the Arctic, according to a study published July 8, 2020 in the open-access journal PLOS ONE by Alfio Alessandro Chiarenza of the Imperial College London, UK, and co-authors Anthony R. Fiorillo, Ronald S. Tykoski, Paul J. McCarthy, Peter P. Flaig, and Dori L. Contreras.

Dromaeosaurids are a group of predatory dinosaurs closely related to birds, whose members include well-known species such as Deinonychus and Velociraptor. These dinosaurs lived all over the world, but their bones are often small and delicate and rarely preserve well in the fossil record, complicating efforts to understand the paths they took as they dispersed between continents.

The Prince Creek Formation of northern Alaska preserves the largest collection of polar dinosaur fossils in the world, dating to about 70 million years ago, but the only dromaeosaurid remains found so far have been isolated teeth. The jaw fossil described in this study is a mere 14mm long and preserves only the tip of the lower jaw, but it is the first known non-dental dromaeosaurid fossil from the Arctic. Statistical analysis indicates this bone belongs to a close relative of the North American Saurornitholestes.

North American dromaeosaurids are thought to trace their origins to Asia, and Alaska would have been a key region for the dispersal of their ancestors. This new fossil is a tantalizing clue toward understanding what kinds of dromaeosaurs inhabited this crucial region. Furthermore, the early developmental stage of the bone suggests this individual was still young and was likely born nearby; in contrast to previous suggestions that this part of Alaska was exclusively a migratory pathway for many dinosaurs, this is strong evidence that some dinosaurs were nesting here. The authors suggest that future findings may allow a more complete understanding of these mysterious Arctic dromaeosaurids.

Chiarenza summarizes: “There are places where dinosaur fossils are so common that a scrap of bone, in most cases, cannot really add anything scientifically informative anymore: this is not the case with this Alaskan specimen. Even with such an incomplete jaw fragment, our team was not only able to work out the evolutionary relationships of this dinosaur, but also to picture something more on the biology of these animals, ultimately gaining more information on this Ancient Arctic ecosystem.” Fiorillo adds: “Years ago when dinosaurs were first found in the far north, the idea challenged what we think we know about dinosaurs. For some time afterwards, there was a great debate as to whether or not those Arctic dinosaurs migrated or lived in the north year-round. All of those arguments were somewhat speculative in nature. This study of a predatory dinosaur jaw from a baby provides the first physical proof that at least some dinosaurs not only lived in the far north, but they thrived there. One might even say, our study shows that the ancient north was a great place to raise a family and now we have to figure out why.”

How dinosaurs became extinct, video


This 8 July 2020 video says about itself:

Why the Dinosaurs’ Extinction is an Ongoing Puzzle | Nat Geo Explores

Dinosaurs ruled the world for roughly 140 million years—until they suddenly disappeared. While decades of research point to an asteroid impact at Chicxulub crater as the end of the dinosaurs’ reign 66 million years ago, scientists weren’t always so sure what happened to these mesmerizing creatures. Theories varied wildly throughout the twentieth century as the field of paleontology grew, but it wasn’t until the 1980s that one theory emerged as a major breakthrough in the extinction mystery. Today’s scientists continue to piece together the puzzle with discoveries that give us a clearer picture of what happened to the dinosaurs.

Dilophosaurus dinosaurs, new research


This 2018 video says about itself:

What Jurassic Park Got WRONG – The Dilophosaurus

Jurassic Park brought millions of people around the world to fall in love with Dinosaurs, but they wrong about some key aspects regarding the Dilophosaurus. With Jurassic World Fallen Kingdom nearing release, we want to take you on a ride looking over the Dinosaurs brought to life by Ingen and the makers of Jurassic Park, and see how they stack up to the real thing!

From the University of Texas at Austin in the USA:

Famous ‘Jurassic Park’ dinosaur is less lizard, more bird

July 7, 2020

From movies to museum exhibits, the dinosaur Dilophosaurus is no stranger to pop culture. Many probably remember it best from the movie “Jurassic Park,” where it’s depicted as a venom-spitting beast with a rattling frill around its neck and two paddle-like crests on its head.

The dinosaur in the movie is mostly imagination, but a new comprehensive analysis of Dilophosaurus fossils is helping to set the record straight. Far from the small lizard-like dinosaur in the movies, the actual Dilophosaurus was the largest land animal of its time, reaching up to 20 feet in length, and it had much in common with modern birds.

The analysis was published open access in the Journal of Paleontology on July 7.

Dilophosaurus lived 183 million years ago during the Early Jurassic. Despite big-screen fame, scientists knew surprisingly little about how the dinosaur looked or fit into the family tree, until now.

“It’s pretty much the best, worst-known dinosaur,” said lead author Adam Marsh. “Until this study, nobody knew what Dilophosaurus looked like or how it evolved.”

Seeking answers to these questions, Marsh conducted an analysis of the five most-complete Dilophosaurus specimens while earning his Ph.D. from The University of Texas at Austin’s Jackson School of Geosciences. He is now the lead paleontologist at Petrified Forest National Park.

The analysis is co-authored by Jackson School Professor Timothy Rowe, who discovered two of the five Dilophosaurus specimens that were studied.

The study adds clarity to a muddled research record that reaches back to the first Dilophosaurus fossil to be discovered, the specimen that set the standard for all following Dilophosaurus discoveries. That fossil was rebuilt with plaster, but the 1954 paper describing the find isn’t clear about what was reconstructed — a fact that makes it difficult to determine how much of the early work was based on the actual fossil record, Marsh said.

Early descriptions characterize the dinosaur as having a fragile crest and weak jaws, a description that influenced the depiction of Dilophosaurus in the “Jurassic Park” book and movie as a svelte dinosaur that subdued its prey with venom.

But Marsh found the opposite. The jawbones show signs of serving as scaffolding for powerful muscles. He also found that some bones were mottled with air pockets, which would have helped reinforce the skeleton, including its dual crest.

“They’re kind of like bubble wrap — the bone is protected and strengthened,” Marsh said.

These air sacs are not unique to Dilophosaurus. Modern birds and the world’s most massive dinosaurs also have bones filled with air. In both cases, the air sacs lighten the load, which helped big dinosaurs manage their bulky bodies and birds take to the skies.

Many birds use the air sacs to perform other functions, from inflating stretchy areas of skin during mating rituals, to creating booming calls and dispersing heat. The intricate array of air pockets and ducts that extend from Dilophosaurus’ sinus cavity into its crests means that the dinosaur may have been able to perform similar feats with its headgear.

All the specimens Marsh examined came from the Kayenta Formation in Arizona and belong to the Navajo Nation. The University of California Museum of Paleontology holds in trust three of the specimens. The Jackson School Museum of Earth History holds the two discovered by Rowe.

“One of the most important responsibilities of our museum is curation,” said Matthew Brown, director of the Vertebrate Paleontology Collections. “We are very excited to help share these iconic Navajo Nation fossils with the world through research and educational outreach, as well as preserve them for future generations.”

To learn more about how the fossils compared with one another, Marsh recorded hundreds of anatomical characteristics of each fossil. He then used an algorithm to see how the specimens compared with the first fossil — which confirmed that they were indeed all Dilophosaurus.

The algorithm also revealed that there’s a significant evolutionary gap between Dilophosaurus and its closest dinosaur relatives, which indicates there are probably many other relatives yet to be discovered.

The revised Dilophosaurus record will help paleontologists better identify specimens going forward. Marsh said that the research is already being put into action. In the midst of his analysis, he discovered that a small braincase in the Jackson School’s collections belonged to a Dilophosaurus.

“We realized that it wasn’t a new type of dinosaur, but a juvenile Dilophosaurus, which is really cool,” Marsh said.

Small ancestor of dinosaurs and pterosaurs discovered


Life restoration of Kongonaphon kely, a newly described reptile near the ancestry of dinosaurs and pterosaurs, in what would have been its natural environment in the Triassic (~237 million years ago). © Alex Boersma

From the American Museum of Natural History in the USA:

A tiny ancient relative of dinosaurs and pterosaurs discovered

New study suggests a miniaturized origin for some of the largest animals ever to live on Earth

July 6, 2020

Dinosaurs and flying pterosaurs may be known for their remarkable size, but a newly described species from Madagascar that lived around 237 million years ago suggests that they originated from extremely small ancestors. The fossil reptile, named Kongonaphon kely, or “tiny bug slayer”, would have stood just 10 centimeters (or about 4 inches) tall. The description and analysis of this fossil and its relatives, published today in the journal Proceedings of the National Academy of Sciences, may help explain the origins of flight in pterosaurs, the presence of “fuzz” on the skin of both pterosaurs and dinosaurs, and other questions about these charismatic animals.

“There’s a general perception of dinosaurs as being giants,” said Christian Kammerer, a research curator in paleontology at the North Carolina Museum of Natural Sciences and a former Gerstner Scholar at the American Museum of Natural History. “But this new animal is very close to the divergence of dinosaurs and pterosaurs, and it’s shockingly small.”

Dinosaurs and pterosaurs both belong to the group Ornithodira. Their origins, however, are poorly known, as few specimens from near the root of this lineage have been found. The fossils of Kongonaphon were discovered in 1998 in Madagascar by a team of researchers led by American Museum of Natural History Frick Curator of Fossil Mammals John Flynn (who worked at The Field Museum at the time) in close collaboration with scientists and students at the University of Antananarivo, and project co-leader Andre Wyss, chair and professor of the University of California-Santa Barbara’s Department of Earth Science and an American Museum of Natural History research associate.

“This fossil site in southwestern Madagascar from a poorly known time interval globally has produced some amazing fossils, and this tiny specimen was jumbled in among the hundreds we’ve collected from the site over the years,” Flynn said. “It took some time before we could focus on these bones, but once we did, it was clear we had something unique and worth a closer look. This is a great case for why field discoveries — combined with modern technology to analyze the fossils recovered — is still so important.”

“Discovery of this tiny relative of dinosaurs and pterosaurs emphasizes the importance of Madagascar’s fossil record for improving knowledge of vertebrate history during times that are poorly known in other places,” said project co-leader Lovasoa Ranivoharimanana, professor and director of the vertebrate paleontology laboratory at the University of Antananarivo in Madagascar. “Over two decades, our collaborative Madagascar-U.S. teams have trained many Malagasy students in paleontological sciences, and discoveries like this helps people in Madagascar and around the world better appreciate the exceptional record of ancient life preserved in the rocks of our country.”

Kongonaphon isn’t the first small animal known near the root of the ornithodiran family tree, but previously, such specimens were considered “isolated exceptions to the rule,” Kammerer noted. In general, the scientific thought was that body size remained similar among the first archosaurs — the larger reptile group that includes birds, crocodilians, non-avian dinosaurs, and pterosaurs — and the earliest ornithodirans, before increasing to gigantic proportions in the dinosaur lineage.

“Recent discoveries like Kongonaphon have given us a much better understanding of the early evolution of ornithodirans. Analyzing changes in body size throughout archosaur evolution, we found compelling evidence that it decreased sharply early in the history of the dinosaur-pterosaur lineage,” Kammerer said.

This “miniaturization” event indicates that the dinosaur and pterosaur lineages originated from extremely small ancestors yielding important implications for their paleobiology. For instance, wear on the teeth of Kongonaphon suggests it ate insects. A shift to insectivory, which is associated with small body size, may have helped early ornithodirans survive by occupying a niche different from their mostly meat-eating contemporaneous relatives.

The work also suggests that fuzzy skin coverings ranging from simple filaments to feathers, known on both the dinosaur and pterosaur sides of the ornithodiran tree, may have originated for thermoregulation in this small-bodied common ancestor. That’s because heat retention in small bodies is difficult, and the mid-late Triassic was a time of climatic extremes, inferred to have sharp shifts in temperature between hot days and cold nights.

Sterling Nesbitt, an assistant professor at Virginia Tech and a Museum research associate and expert in ornithodiran anatomy, phylogeny, and histological age analyses, is also an author on this study.

This study was supported, in part, by the National Geographic Society, a Gerstner Scholars Fellowship from the Gerstner Family Foundation and the Richard Gilder Graduate School, the Division of Paleontology at the American Museum of Natural History, and a Meeker Family Fellowship from the Field Museum, with additional support from the Ministry of Energy and Mines of Madagascar, the World Wide Fund for Nature (Madagascar), University of Antananarivo, and MICET/ICTE (Madagascar).

Dinosaur footprints, new research


This 2018 video says about itself:

World’s Largest Dinosaur Footprints

The National Park Toro Toro is a blast from the Jurassic era, and almost like the movie Jurassic Park. Join me in one of Bolivia’s least visited places and hidden gems.

From Brown University in the USA:

Different tracks, same dinosaurs: Researchers dig deeper into dinosaur movements

July 1, 2020

When picturing dinosaur tracks, most people imagine a perfectly preserved mold of a foot on a firm layer of earth. But what if that dinosaur was running through mud, sinking several inches — or even up to their ankles — into the ground as it moved?

Using sophisticated X-ray-based technology, a team of Brown University researchers tracked the movements of guineafowl to investigate how their feet move below ground through various substrates and what those findings could mean for understanding fossil records left behind by dinosaurs.

They found that regardless of the variability in substrates, or the guineafowl moving at different speeds, sinking at different depths or engaging in different behaviors, the birds’ overall foot movement remained the same: The toes spread as they stepped onto the substrate surface, remained spread as the foot sank, collapsed and drew back as they were lifted from the substrate, and exited the substrate in front of the point of entry, creating a looping pattern as they walked.

And part of what that means is that fossilized dinosaur tracks that look distinct from each other, and appear to be from different species, might instead come from the same dinosaurs.

“This is the first study that’s really shown how the bird foot is moving below ground, showing the patterns of this subsurface foot motion and allowing us to break down the patterns that we’re seeing in a living animal that has feet similar to those of a dinosaur,” said Morgan Turner, a Ph.D. candidate at Brown in ecology and evolutionary biology and lead author of the research. “Below ground, or even above ground, they’re responding to these soft substrates in a very similar way, which has potentially important implications for our ability to study the movement of these animals that we can’t observe directly anymore.”

The findings were published on Wednesday, July 1, in the Royal Society journal Biology Letters.

To make the observations, Turner and her colleagues, Professor of Biology and Medical Science Stephen Gatesy and Peter Falkingham, now at Liverpool John Moores University, used a 3D-imaging technology developed at Brown called X-ray Reconstruction of Moving Morphology (XROMM). The technology combines CT scans of a skeleton with high-speed X-ray video, aided by tiny implanted metal markers, to create visualizations of how bones and muscles move inside humans and animals. In the study, the team used XROMM to watch guineafowl move through substrates of different hydration and compactness, analyzing how their feet moved underground and the tracks left behind.

Sand, typically a dense combination of quartz and silica, does not lend itself well to X-ray imaging, so the team used poppy seeds to emulate sand. Muds were made using small glass bubbles, adding various amount of clay and water across 107 trials to achieve different consistencies and realistic tracks.

They added metal markers underneath the claws of the guineafowl to allow for tracking in 3D space. It’s these claw tips that the researchers think are least disturbed by mud flow and other variables that can impact and distort the form of the track.

Despite the variation, the researchers observed a consistent looping pattern.

“The loops by themselves I don’t think are that interesting,” Gatesy said. “People are like, ‘That’s nice. Birds do this underground. So what?’ It was only when [Turner] went back into it and said, ‘What if we slice those motion trails at different depths as if they were footprints?’ Then we made the nice connection to the fossils.”

By “slicing” through the 3D images of the movement patterns at different depths, the researchers found similarities between the guineafowl tracks and fossilized dinosaur tracks.

“We don’t know what these dinosaurs were doing, we don’t know what they were walking through exactly, we don’t know how big they were or how deep they were sinking, but we can make this really strong connection between how they were moving and some level of context for where this track is being sampled from within that movement,” Turner said.

By recognizing the movement patterns, as well as the entry and exit point of the foot through various substrates, the team says they’re able to gain a better understanding of what a dinosaur track could look like.

“You end up generating this big diversity of track shapes from a very simple foot shape because you’re sampling at different depths and it’s moving in complicated ways,” Gatesy said. “Do we really have 40 different kinds of creatures, each with a differently shaped foot, or are we looking at some more complicated interaction that leaves behind these remnants that are partly anatomical and partly motion and partly depth?”

To further their research, the team spent time at the Beneski Museum of Natural History at Amherst College in Massachusetts, which is home to an expansive collection of penetrative tracks discovered in the 1800s by geologist Edward Hitchcock.

Hitchcock originally believed that his collection housed fossil tracks from over 100 distinct animals. Because of the team’s work with XROMM, Gatesy now thinks it’s possible that at least half of those tracks are actually from the same dinosaurs, just moving their feet in slightly different ways or sampled at slightly different depths.

“Going to museum together and being able to pick out these features and say, ‘We think this track is low in the loop and we think this one is high,’ that was the biggest moment of insight for me,” Turner said.

Turner says she hopes their research can lead to a greater interest in penetrative tracks, even if they seem a little less pretty or polished than the tracks people are used to seeing in museums.

“They have so much information in them,” Turner said, “and I hope that this gives people a lens, a new way to view these footprints and appreciate the movement preserved within in them.”

This work was supported by the US National Science Foundation (EAR 1452119 to SMG and PLF; IOS 0925077 to SMG), a Marie Curie International Outgoing Fellowship within the 7th European Framework Programme to PLF, and the Bushnell Research and Education Fund to MLT.

1300 Japanese little dinosaur eggshell fossils discovered


An egg of Himeoolithus murakamii (left), outlined egg with intact eggshell remains (black area) (middle), and reconstruction of Himeoolithus murakamii and their probable parent dinosaur (right). Photo by University of Tsukuba and Museum of Nature and Human Activities, Hyogo, Japan

This 23 June 2020 Japanese video is about the new dinosaur eggs discovery.

From the University of Tsukuba in Japan:

Tiny Japanese dinosaur eggs help unscramble Cretaceous ecosystem

June 26, 2020

Summary: A research team has excavated over 1300 eggshell fossils from the Lower Cretaceous Ohyamashimo Formation of Hyogo Prefecture, Japan. Over 96% of these fossils, including numerous fragments, four partial and almost complete eggs in an in situ nest, belonged to a new ootaxon the authors named Himeoolithus murakamii, attributed to a small non-avian theropod dinosaur. The remaining eggshell fragments, belonging to five additional small theropod ootaxa, showed notable biodiversity.

When most of us think of dinosaurs, we envision large, lumbering beasts, but these giants shared their ecosystems with much smaller dinosaurs, the smaller skeletons of which were generally less likely to be preserved. The fossilized eggshells of these small dinosaurs can shed light on this lost ecological diversity.

Led by the University of Tsukuba, researchers scoured an exceptional fossil egg site first discovered in 2015 in Hyogo Prefecture, southwestern Japan, and reported their findings in a new study published in Cretaceous Research.

The Kamitaki Egg Quarry, found in a red-brown mudstone layer of the Ohyamashimo Formation, deposited in an Early Cretaceous (about 110 million years old) river flood plain, was carefully and intensively excavated in the winter of 2019, and yielded over 1300 egg fossils. Most were isolated fragments, but there were a few partial and almost complete eggs.

According to lead author Professor Kohei Tanaka, “our taphonomic analysis indicated that the nest we found was in situ, not transported and redeposited, because most of the eggshell fragments were positioned concave-up, not concave-down like we see when eggshells are transported.”

Most of these fossil eggs belong to a new egg genus and species, called Himeoolithus murakamii, and are exceptionally small, with an estimated mass of 9.9 grams — about the size of a modern quail egg. However, biological classification analysis implies that the eggs belonged not to early birds, but to their cousins, the non-avian theropod dinosaurs (the group that includes well-known carnivores like Tyrannosaurus and Velociraptor). That puts Himeoolithus murakamii among the smallest non-avian theropod eggs reported to date. These tiny eggs were notably elongated in shape — unusual for similarly small eggs among Cretaceous birds, but typical among larger non-avian theropod eggs.

In addition to the abundant Himeoolithus murakamii eggshells, five more ootaxa (distinct types of egg fossils) were recognized in the Kamitaki locality. All of these ootaxa belonged to small non-avian theropods.

As Professor Tanaka explains, “the high diversity of these small theropod eggs makes this one of the most diverse Early Cretaceous egg localities known. Small theropod skeletal fossils are quite scarce in this area. Therefore, these fossil eggs provide a useful window into the hidden ecological diversity of dinosaurs in the Early Cretaceous of southwestern Japan, as well as into the nesting behavior of small non-avian theropods.”

This music video is called Jonathan Richman – I’m A Little Dinosaur.

How dinosaurs survived Arctic cold


This 24 June 2020 video says about itself:

When Dinosaurs Chilled in the Arctic

All told, the Arctic in the Cretaceous Period was a rough place to live, especially in winter. And yet, the fossils of many kinds of dinosaurs have been discovered there. So how were they able to survive in this harsh environment?

How birds’ beaks evolved


This 18 June 2020 video says about itself:

How Birds Got (And Kept) Their Beaks

Birds are known for having beaks, however at what point between being a humongous therapod and tiny sparrow did they get them, and why?

Hosted by: Hank Green