New mosasaur genus discovered


A skeletal mount of the mosasaur Gnathomortis stadtmani at BYU’s Eyring Science Center. Image credit: BYU

From Utah State University in the USA:

Jaws of death: Paleontologist renames giant, prehistoric marine lizard

September 23, 2020

Summary: Paleontologists describe a new genus of mosasaur, Gnathomortis stadtmani, a marine lizard that roamed the oceans of North America toward the end of the Age of Dinosaurs.

Some 92 to 66 million years ago, as the Age of Dinosaurs waned, giant marine lizards called mosasaurs roamed an ocean that covered North America from Utah to Missouri and Texas to the Yukon. The air-breathing predators were streamlined swimmers that devoured almost everything in their path, including fish, turtles, clams and even smaller mosasaurs.

Coloradoan Gary Thompson discovered mosasaur bones near the Delta County town of Cedaredge in 1975, which the teen reported to his high school science teacher. The specimens made their way to Utah’s Brigham Young University, where, in 1999, the creature that left the fossils was named Prognathodon stadtmani.

“I first learned of this discovery while doing background research for my Ph.D.,” says newly arrived Utah State University Eastern paleontologist Joshua Lively, who recently took the reins as curator of the Price campus’ Prehistoric Museum. “Ultimately, parts of this fossil, which were prepared since the original description in 1999, were important enough to become a chapter in my 2019 doctoral dissertation.”

Upon detailed research of the mosasaur’s skeleton and a phylogenetic analysis, Lively determined the BYU specimen is not closely related to other species of the genus Prognathodon and needed to be renamed. He reclassified the mosasaur as Gnathomortis stadtmani and reports his findings in the most recent issue of the Journal of Vertebrate Paleontology.

His research was funded by the Geological Society of America, the Evolving Earth Foundation, the Texas Academy of Science and the Jackson School of Geosciences at The University of Texas at Austin.

“The new name is derived from Greek and Latin words for ‘jaws of death,'” Lively says. “It was inspired by the incredibly large jaws of this specimen, which measure four feet (1.2 meters) in length.”

An interesting feature of Gnathomortis’ mandibles, he says, is a large depression on their outer surface, similar to that seen in modern lizards, such as the Collared Lizard. The feature is indicative of large jaw muscles that equipped the marine reptile with a formidable biteforce.

“What sets this animal apart from other mosasaurs are features of the quadrate — a bone in the jaw joint that also forms a portion of the ear canal,” says Lively, who returned to the fossil’s Colorado discovery site and determined the age interval of rock, in which the specimen was preserved.

“In Gnathomortis, this bone exhibits a suite of characteristics that are transitional from earlier mosasaurs, like Clidastes, and later mosasaurs, like Prognathodon. We now know Gnathomortis swam in the seas of Colorado between 79 and 81 million years ago, or at least 3.5 million years before any species of Prognathodon.”

He says fossil enthusiasts can view Gnathomortis’ big bite at the BYU Museum of Paleontology in Provo, Utah, and see a cast of the skull at the Pioneer Town Museum in Cedaredge, Colorado. Reconstructions of the full skeleton are on display at the John Wesley Powell River History Museum in Green River, Utah, and in BYU’s Eyring Science Center.

“I’m excited to share this story, which represents years of effort by many citizen scientists and scholars, as I kick off my new position at USU Eastern’s Prehistoric Museum,” Lively says. “It’s a reminder of the power of curiosity and exploration by people of all ages and backgrounds.”

World’s oldest, dinosaur age, animal sperm discovery


This 17 September 2020 video says about itself:

100 Million-Year-Old Sperm Is The Oldest Ever Found. And It’s Giant

The oldest known sperm in the world has been discovered, locked in a piece of amber that solidified when behemoths like Spinosaurus dominated the Earth.

From Queen Mary University of London in England:

World’s oldest animal sperm found in tiny crustaceans trapped in Myanmar amber

September 16, 2020

An international collaboration between researchers at Queen Mary University of London and the Chinese Academy of Science in Nanjing has led to the discovery of world’s oldest animal sperm inside a tiny crustacean trapped in amber around 100 million years ago in Myanmar.

The research team, led by Dr He Wang of the Chinese Academy of Science in Nanjing, found the sperm in a new species of crustacean they named Myanmarcypris hui. They predict that the animals had sex just before their entrapment in the piece of amber (tree resin), which formed in the Cretaceous period.

Fossilised sperm are exceptionally rare; previously the oldest known examples were only 17 million years old. Myanmarcypris hui is an ostracod, a kind of crustacean that has existed for 500 million years and lives in all kinds of aquatic environments from deep oceans to lakes and rivers. Their fossil shells are common and abundant but finding specimens preserved in ancient amber with their appendages and internal organs intact provides a rare and exciting opportunity to learn more about their evolution.

Professor Dave Horne, Professor of Micropalaeontology at Queen Mary University of London said: “Analyses of fossil ostracod shells are hugely informative about past environments and climates, as well as shedding light on evolutionary puzzles, but exceptional occurrences of fossilised soft parts like this result in remarkable advances in our understanding.”

During the Cretaceous period in what is now Myanmar, the ostracods were probably living in a coastal lagoon fringed by trees where they became trapped in a blob of tree resin. The Kachin amber of Myanmar has previously yielded outstanding finds including frogs, snakes and a feathered dinosaur tail. Bo Wang, also of the Chinese Academy of Science in Nanjing added: “Hundreds of new species have been described in the past five years, and many of them have made evolutionary biologists re-consider long-standing hypotheses on how certain lineages developed and how ecological relationships evolved.”

The study, published in Royal Society Proceedings B, also has implications for understanding the evolutionary history of an unusual mode of sexual reproduction involving “giant sperm.”

The new ostracod finds may be extremely small but in one sense they are giants. Males of most animals (including humans) typically produce tens of millions of really small sperm in very large quantities, but there are exceptions. Some tiny fruit flies (insects) and ostracods (crustaceans) are famous for investing in quality rather than quantity: relatively small numbers of “giant” sperm that are many times longer than the animal itself, a by-product of evolutionary competition for reproductive success. The new discovery is not only by far the oldest example of fossil sperm ever found but also shows that these ostracods had already evolved giant sperm, and specially-adapted organs to transfer them from male to female, 100 million years ago.

Each ostracod is less than a millimetre long. Using X-ray microscopy the team made computer-aided 3-D reconstructions of the ostracods embedded in the amber, revealing incredible detail. “The results were amazing — not only did we find their tiny appendages to be preserved inside their shells, we could also see their reproductive organs,” added He Wang. “But when we identified the sperm inside the female, and knowing the age of the amber, it was one of those special Eureka-moments in a researcher’s life.”

Wang’s team found adult males and females but it was a female specimen that contained the sperm, indicating that it must have had sex shortly before becoming trapped in the amber. The reconstructions also revealed the distinctive muscular sperm pumps and penises (two of each) that male ostracods use to inseminate the females, who store them in bag-like receptacles until eggs are ready to be fertilised.

Such extensive adaptation raises the question of whether reproduction with giant sperms can be an evolutionarily-stable character. “To show that using giant sperms in reproduction is not an extinction-doomed extravagance of evolution, but a serious long-term advantage for the survival of a species, we need to know when they first appeared” says co-author Dr Renate Matzke-Karasz of Ludwig-Maximilians-University in Munich.

This new evidence of the persistence of reproduction with giant sperm for a hundred million years shows it to be a highly successful reproductive strategy that evolved only once in this group — quite impressive for a trait that demands such a substantial investment from both males and females, especially when you consider that many ostracods can reproduce asexually, without needing males at all. “Sexual reproduction with giant sperm must be very advantageous” says Matzke-Karasz.

Sauropod dinosaurs had rhino-like horns, embryos show


This 2016 video from the American Museum of Natural History in the USA says about itself:

Measuring 122 feet, the Museum’s new exhibit, The Titanosaur, is big–so big that its head extends outside of the Museum’s fourth-floor gallery where it is now on permanent display.

This species of dinosaur, a giant herbivore that belongs to a group known as titanosaurs, is so new that it has not yet been formally named by the paleontologists who discovered it. The Titanosaur lived in the forests of today’s Patagonia about 100 to 95 million years ago, during the Late Cretaceous period, and weighed 70 tons. It is one of the largest dinosaurs ever discovered.

The fossils on which this cast is based were excavated in the Patagonian desert region of Argentina by a team from the Museo Paleontologico Egidio Feruglio led by José Luis Carballido and Diego Pol, who received his Ph.D. at the American Museum of Natural History.

In this video, Dr. Mark Norell, chair and Macaulay Curator in the Division of Paleontology, describes how such a massive animal could have supported its own weight and why the Titanosaur is one of the more spectacular finds during what he describes as “the golden age of paleontology.”

From the University of Manchester in England:

Newly discovered rare dinosaur embryos show sauropods had rhino-like horns

August 27, 2020

An incredibly rare dinosaur embryo discovered perfectly preserved inside its egg has shown scientists new details of the development and appearance of sauropods which lived 80 million years ago.

Sauropods were the giant herbivores made famous as being ‘veggie-saurs’ in the 1993 film Jurassic Park. The incredible new find of an intact embryo has shown for the first time that these dinosaurs had stereoscopic vision and a horn on the front of the face which was then lost in adulthood.

The international research team say that this is the most complete and articulate skull known from any titanosaur, the last surviving group of long-necked sauropods and largest land animals known to have ever existed.

The sauropod egg was discovered in Patagonia, Argentina, in an area not previously known to provide evidence of dinosaur fossils. It was imperative the egg was repatriated to Argentina however as it is illegal to permanently remove fossils from the country.

Dr John Nudds from The University of Manchester said: “The preservation of embryonic dinosaurs preserved inside their eggs is extremely rare. Imagine the huge sauropods from Jurassic Park and consider that the tiny skulls of their babies, still inside their eggs, are just a couple of centimetres long.

“We were able to reconstruct the embryonic skull prior to hatching. The embryos possessed a specialised craniofacial anatomy that precedes the post-natal transformation of the skull in adult sauropods. Part of the skull of these embryonic sauropods was extended into an elongated snout or horn, so that they possessed a peculiarly shaped face.”

The examination of the amazing specimen enabled the team to revise opinions of how babies of these giant dinosaurs may be hatched and to test previously held ideas about sauropodomorph reproduction. The elongated horn is now thought to have been used as an ‘egg tooth’ on hatching to allow babies to break through their shell.

The findings, published today in Current Biology, were the result of a novel technique to reveal embryonic dinosaurs in their shells. The embryo within the egg was revealed by carefully dissolving the egg around it using an acid preparation. The team were then able to perform a virtual dissection of the specimen at the European Synchrotron Radiation Facility (ESRF) in Grenoble.

Sauropod embryology remains one of the least explored areas of the life history of dinosaurs. The first definitive discovery of sauropod embryos came with the finding of an enormous nesting ground of titanosaurian dinosaurs discovered in Upper Cretaceous deposits of northern Patagonia, Argentina, 25 years ago. This new discovery however, is the first time a fully intact embryo has been able to be studied.

Other eggs were also found at the Argentinian site which the scientists now aim to examine in a similar fashion. It is thought that some of the eggs could contain well-preserved dinosaur skin which could help further piece together the mysteries of some of the most fascinating animals to ever walk the Earth.

Dinosaur age turtle and its invertebrate guests


This March 2018 video is called The Evolution of Turtles.

From Waseda University in Japan:

Life in a nutshell: New species found in the carapace of late Cretaceous marine turtle

August 25, 2020

Summary: Scientists have identified a new ichnospecies from the shell of an extinct marine turtle fossil, the first known species coexisting on living marine vertebrates.

While paleontologists have a wealth of vertebrate fossils at their disposal, their knowledge of the ecology of ancient extinct species, particularly regarding their relationship with invertebrate species, is relatively poor. As bones and hard shells “fossilize” much better than soft tissues and cartilage, scientists are limited in their ability to infer the presence of parasitic or symbiotic organisms living in or on these ancient vertebrates. As a result, relatively little is known about the evolutionary relationships between these ancient “clades” and their modern descendants.

All hope is not lost, though, as researchers can infer the presence of these small organisms from the footprints they left behind. These records are called trace fossils, or ichnofossils. One clear example of such ichnofossils is the boreholes that many mollusks make in the turtle shell remains and whale and fish bones on the ocean floor. However, to this date, there have been no indications that such species also lived in the shell while the turtle was alive and well.

In their recent study published in the journal Palaios, Assistant Professor Kei Sato from Waseda University and Associate Professor Robert G Jenkins from Kanazawa University focused on the trace evidence left on the carapace (shell) of an extinct basal leatherback marine turtle (Mesodermochelys sp.). The fossil was recovered from an Upper Cretaceous formation in Nio River, Japan, and the evidence in question were 43 tiny, flask-shaped boreholes all over the turtle shell fossil.

Eager to learn more about the organisms responsible for this, the scientists formulated a hypothesis, based on previous borehole evidence found on ancient marine turtle shells. After observing the fossil up close and measuring the morphological characteristics of the boreholes, they produced a 3-dimensional reconstruction of the carapace and the cross-section of one of the boreholes, which allowed them to observe the intricate details left by the species.

Sato, who is the lead author of this study, elaborates on the surprising evidence they found, “We saw that there were signs of healing around the mouth of boreholes, suggesting that the turtle was alive when the organisms settled on the carapace.” Based on the morphology and positioning of the boreholes, they determined that the likely culprits for these boreholes were “bivalves” from the superfamily Pholadoidea, creatures similar to the modern clams. These “sessile” (or immobile) organisms normally require a stable substrate to bore into, and the turtle carapace was a suitable host. The fact that the host animal was swimming around freely probably helped, as this allowed exposure to new environments.

Sato and Jenkins identified the boreholes called Karethraichnus; however, they were unable to match the characteristics of the boreholes they found with those made by any currently described species. This only meant one thing: that they had stumbled onto a completely new species! They have accordingly named this new species as Karethraichnus zaratan.

Sato is excited about the implications of their findings, stating, “This is the first study to report this unique behavior of boring bivalves as a symbiont of living marine vertebrate, which is a significant finding for the paleoecology and evolution of ancient boring bivalve clades.” Previously, no such species had been shown to live on the carapace of living vertebrates. Instead, they were often reported to occur on the remains of marine turtles and other vertebrates, laying on the ocean floor alongside various decomposing organisms. By attaching themselves on a live, free-swimming substrate, such as the carapace of a marine turtle, these pholadoid bivalves may have paved the way for a novel, yet-unknown evolutionary path of accessing previously unexplored niches and diversifying into new species. As the tracemaker bivalves of Karethraichnus zaratan are considered to belong to one of the basal groups for Pholadoidea, this knowledge is crucial for understanding the evolutionary history of extant organisms in this group.

New Isle of Wight, England, dinosaur discovery


This 13 August 2020 video says about itself:

A new species of dinosaur has been discovered in the UK! Four bones were found last year on a beach off England’s south coast and after careful examination, scientists now reckon it’s a new dino. It’s called the Vectaerovenator inopinatus, which translates to the air-filled hunter.

Researchers say it is a theropod dinosaur that lived in the Cretaceous period 115 million years ago which means it’s a relative of modern-day birds and arguably the most famous dino – the Tyrannosaurus rex! Researchers say they’re still learning more about the new species and are hoping for some more beachside discoveries to help them put the pieces together.

From the University of Southampton in England:

New species of dinosaur discovered on Isle of Wight

August 11, 2020

A new study by palaeontologists at the University of Southampton suggests four bones recently found on the Isle of Wight belong to new species of theropod dinosaur, the group that includes Tyrannosaurus rex and modern-day birds.

The dinosaur lived in the Cretaceous period 115 million years ago and is estimated to have been up to four metres long.

The bones were discovered on the foreshore at Shanklin last year and are from the neck, back and tail of the new dinosaur, which has been named Vectaerovenator inopinatus.

The name refers to the large air spaces in some of the bones, one of the traits that helped the scientists identify its theropod origins. These air sacs, also seen in modern birds, were extensions of the lung, and it is likely they helped fuel an efficient breathing system while also making the skeleton lighter.

The fossils were found over a period of weeks in 2019 in three separate discoveries, two by individuals and one by a family group, who all handed in their finds to the nearby Dinosaur Isle Museum at Sandown.

The scientific study has confirmed the fossils are very likely to be from the same individual dinosaur, with the exact location and timing of the finds adding to this belief.

Robin Ward, a regular fossil hunter from Stratford-upon-Avon, was with his family visiting the Isle of Wight when they made their discovery. He said: “The joy of finding the bones we discovered was absolutely fantastic. I thought they were special and so took them along when we visited Dinosaur Isle Museum. They immediately knew these were something rare and asked if we could donate them to the museum to be fully researched.”

James Lockyer, from Spalding, Lincolnshire was also visiting the Island when he found another of the bones. Also a regular fossil hunter, he said: “It looked different from marine reptile vertebrae I have come across in the past. I was searching a spot at Shanklin and had been told and read that I wouldn’t find much there. However, I always make sure I search the areas others do not, and on this occasion, it paid off.”

Paul Farrell, from Ryde, Isle of Wight, added: “I was walking along the beach, kicking stones and came across what looked like a bone from a dinosaur. I was really shocked to find out it could be a new species.”

After studying the four vertebrae, paleontologists from the University of Southampton confirmed that the bones are likely to belong to a genus of dinosaur previously unknown to science. Their findings will be published in the journal Papers in Palaeontology, in a paper co-authored by those who discovered the fossils.

Chris Barker, a PhD student at the university who led the study, said: “We were struck by just how hollow this animal was — it’s riddled with air spaces. Parts of its skeleton must have been rather delicate.

“The record of theropod dinosaurs from the ‘mid’ Cretaceous period in Europe isn’t that great, so it’s been really exciting to be able to increase our understanding of the diversity of dinosaur species from this time.

“You don’t usually find dinosaurs in the deposits at Shanklin as they were laid down in a marine habitat. You’re much more likely to find fossil oysters or driftwood, so this is a rare find indeed.”

It is likely that the Vectaerovenator lived in an area just north of where its remains were found, with the carcass having washed out into the shallow sea nearby.

Chris Barker added: “Although we have enough material to be able to determine the general type of dinosaur, we’d ideally like to find more to refine our analysis. We are very grateful for the donation of these fossils to science and for the important role that citizen science can play in palaeontology.”

The Isle of Wight is renowned as one of the top locations for dinosaur remains in Europe, and the new Vectaerovenator fossils will now go on display at the Dinosaur Isle Museum at Sandown, which houses an internationally important collection.

Museum curator, Dr Martin Munt, said: “This remarkable discovery of connected fossils by three different individuals and groups will add to the extensive collection we have and it’s great we can now confirm their significance and put them on display for the public to marvel at.

“We continue to undertake public field trips from the museum and would encourage anyone who finds unusual fossils to bring them in so we can take a closer look. However, fossil hunters should remember to stick to the foreshore, and avoid going near the cliffs which are among the most unstable on the Island.”

Isle of Wight Council Cabinet member for environment and heritage, Councillor John Hobart, said: “This is yet another terrific fossil find on the Island which sheds light on our prehistoric past — all the more so that it is an entirely new species. It will add to the many amazing items on display at the museum.”

Big dinosaur age crocodile Deinosuchus


This July 2019 video says about itself:

Deinosuchus Animation Preview

Locomotion and behavioral extrapolations of large crocodilian, genotype Deinosuchus. Highly dangerous aquatic predator.

From ScienceDaily:

New study confirms the power of Deinosuchus and its ‘teeth the size of bananas’

August 10, 2020

A new study, revisiting fossil specimens from the enormous crocodylian, Deinosuchus, has confirmed that the beast had teeth “the size of bananas,” capable to take down even the very largest of dinosaurs.

And, it wasn’t alone!

The research, published in the Journal of Vertebrate Paleontology, also reveals various kinds of “terror crocodile.” Two species, entitled Deinosuchus hatcheri and Deinosuchus riograndensis lived in the west of America, ranging from Montana to northern Mexico. Another, Deinosuchus schwimmeri, lived along the Atlantic coastal plain from New Jersey to Mississippi. At the time, North America was cut in half by a shallow sea extending from the Arctic Ocean south to the present-day Gulf of Mexico.

Ranging in up to 33 feet in length Deinosuchus, though, has been known to be one of the largest, if not the largest, crocodylian genera ever in existence. It was the largest predator in its ecosystem, outweighing even the largest predatory dinosaurs living alongside them between 75 and 82 million years ago.

From previous studies of cranial remains and bite marks on dinosaur fossil bones, paleontologists have long speculated that the massive beasts preyed on dinosaurs.

Now this new study, led by Dr Adam Cossette sheds new light on the monstrous creature and has further confirmed that it most certainly had the head size and crushing jaw strength to do just that.

“Deinosuchus was a giant that must have terrorized dinosaurs that came to the water’s edge to drink,” says Dr Cossette, from the New York Institute of Technology College of Osteopathic Medicine at Arkansas State University. “Until now, the complete animal was unknown. These new specimens we’ve examined reveal a bizarre, monstrous predator with teeth the size of bananas.”

Co-author Stephanie Drumheller-Horton, a paleontologist at the University of Tennessee, added: “Deinosuchus seems to have been an opportunistic predator, and given that it was so enormous, almost everything in its habitat was on the menu.”

“We actually have multiple examples of bite marks made by D. riograndensis and a species newly described in this study, D. schwimmeri, on turtle shells and dinosaur bones.”

In spite of the genus’s name, which means “terror crocodile,” they were actually more closely related to alligators. Based on its enormous skull, it looked like neither an alligator nor a crocodile. Its snout was long and broad, but inflated at the front around the nose in a way not seen in any other crocodylian, living or extinct. The reason for its enlarged nose is unknown.

“It was a strange animal,” says Brochu. “It shows that crocodylians are not ‘living fossils’ that haven’t changed since the age of dinosaurs. They’ve evolved just as dynamically as any other group.”

Deinosuchus disappeared before the main mass extinction at the end of the age of dinosaurs (Meozoic). The reason for its extinction remains unknown. From here, the authors call for me studies to further understand Deinosuchus.

“It had two large holes are present at the tip of the snout in front of the nose,” Dr Cossette says.

“These holes are unique to Deinosuchus and we do not know what they were for, further research down the line will hopefully help us unpick this mystery and we can learn further about this incredible creature.”

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.

Beelzebufo, big dinosaur age Madagascar frog


This 22 July 2020 video says about itself:

Untangling the origins of Beelzebufo — the giant frog that lived alongside the dinosaurs — turns out to be one of the most bedeviling problems in the history of amphibians.

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.”

Colourful dinosaur age insects discovered


Diverse structural-colored insects in mid-Cretaceous amber from northern Myanmar. Credit: NIGPAS

From the Chinese Academy of Sciences, 30 June 2020:

Amber fossils unlock true color of 99-million-year-old insects

Nature is full of colors, from the radiant shine of a peacock‘s feathers or the bright warning coloration of toxic frogs to the pearl-white camouflage of polar bears.

Usually, fine structural detail necessary for the conservation of color is rarely preserved in the , making most reconstructions of the dependent upon an artist’s imagination.

A research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has now unlocked the secrets of true coloration in 99-million-year-old insects.

Colors offer many clues about the behavior and ecology of animals. They function to keep organisms safe from predators, at the right temperature, or attractive to potential mates. Understanding the coloration of long-extinct animals can help us shed light on ecosystems in the deep geological past.

The study, published in Proceedings of the Royal Society B on July 1, offers a new perspective on the often overlooked, but by no means dull, lives of insects that co-existed alongside dinosaurs in Cretaceous rainforests.

Researchers gathered a treasure trove of 35 amber pieces with exquisitely preserved insects from an amber mine in northern Myanmar.

“The amber is mid-Cretaceous, approximately 99 million years old, dating back to the golden age of dinosaurs. It is essentially resin produced by ancient coniferous trees that grew in a tropical rainforest environment. Animals and plants trapped in the thick resin got preserved, some with life-like fidelity,” said Dr. Cai Chenyang, associate professor at NIGPAS who lead the study.

The rare set of amber fossils includes cuckoo wasps with metallic bluish-green, yellowish-green, purplish-blue or green on the head, thorax, abdomen, and legs. In terms of color, they are almost the same as cuckoo wasps that live today, said Dr. Cai.

The researchers also discovered blue and purple beetle specimens and a metallic dark-green soldier fly. “We have seen thousands of amber fossils but the preservation of color in these specimens is extraordinary,” said Prof. Huang Diying from NIGPAS, a co-author of the study.

“The type of color preserved in the amber fossils is called structural color. It is caused by microscopic structure of the animal’s surface. The surface nanostructure scatters light of specific wavelengths and produces very intense colors. This mechanism is responsible for many of the colors we know from our everyday lives,” explained Prof. Pan Yanhong from NIGPAS, a specialist on palaeocolor reconstruction.

To understand how and why color is preserved in some amber fossils but not in others, and whether the colors seen in fossils are the same as the ones insects paraded more than 99 million years ago, the researchers used diamond knife blades to cut through the exoskeleton of two of the colorful amber wasps and a sample of normal dull cuticle.

Using , they were able to show that colorful amber fossils have a well-preserved exoskeleton nanostructure that scatters light. The unaltered nanostructure of colored insects suggested that the colors preserved in amber may be the same as the ones displayed by them in the Cretaceous. But in fossils that do not preserve color, the cuticular structures are badly damaged, explaining their brown-black appearance.

What kind of information can we learn about the lives of ancient insects from their color?

Extant cuckoo wasps are, as their name suggests, parasites that lay their eggs into the nests of unrelated bees and wasps. Structural coloration has been shown to serve as camouflage in insects, and so it is probable that the color of Cretaceous cuckoo wasps represented an adaptation to avoid detection. “At the moment we also cannot rule out the possibility that the colors played other roles besides camouflage, such as thermoregulation,” adds Dr. Cai.