Reconstructing The Dragonfly And Damselfly Family Tree

Saturday, October 30, 2021

Epiophlebia superstes (Mt. Hokyo, Tsukuba City). Credit: Dr. Alexander Blanke, University of Cologne, Germany

Many people hate insects, but the iridescent colors and elegant flying style of dragonflies and damselflies have made them firm favorites worldwide. They have been around in some form for hundreds of millions of years, but the evolutionary history of these relics of prehistoric life has been poorly understood—until now.

In newly published study, researchers including a member of the University of Tsukuba have applied transcriptomics, a type of gene sequencing, to reconstruct the phylogeny of the insect order Odonata. By calibrating this sequencing using the fossil record, they have been able to determine when dragonflies and damselflies first emerged.

Transcriptomics is the study of the collection of ribonucleic acid (RNA)—known as the transcriptome—that is present in a cell at any given time. This RNA contains a wealth of information and can be used to determine relationships among different members of a species. Understanding these relationships is essential for reconstructing evolutionary histories, or phylogenies, which are essentially like a family tree in a genetic sense.

"This is the first transcriptome-based phylogenetic reconstruction of the order Odonata," says one of the authors of the study Professor Ryuichiro Machida. "We analyzed a total of 2,980 protein-coding genes in 105 species, covering all but two of the order's families."

There are thousands of living (extant) species of Odonata, but few have been analyzed in a phylogenetic context, and most species have been identified or differentiated on the basis of physical characteristics, such as wing patterns or larvae appearance. Although comparing appearances can be useful for extant species, it's not always as helpful when trying to reconstruct evolutionary histories—that's where transcriptomics and fossil calibration are useful.

"A robust and reliable phylogenetic reconstruction is essential for dependable estimates of species divergence times," explains Machida. "Different fossil calibration schemes can be applied, but these can greatly impact the range of estimated dates. We used a comprehensive fossil dataset combining newly assessed fossils with data from the literature to produce a well-resolved and robustly time-calibrated phylogeny for Odonata."

This reconstruction provides the most comprehensive divergence time estimates for Odonata to date, meaning the researchers were able to determine when dragonflies and damselflies first appeared (around 200 million years ago). They were even able to estimate the time at which certain evolutionary characteristics developed, such as ovipositors (tube-shaped organs for laying eggs). Species that once flourished but have since died out were also identified. Given that these species can now only be identified in the fossil record, transcriptomics and phylogenetic reconstructions provide a unique opportunity to better understand the connections between extant and extinct species. Studies of a similar nature could shed light on equally obscured genetic histories for other species.

More information: Manpreet Kohli et al, Evolutionary history and divergence times of Odonata (dragonflies and damselflies) revealed through transcriptomics, iScience (2021). DOI: 10.1016/j.isci.2021.103324

Journal information: iScience 

Provided by University of Tsukuba


Babies of Cretaceous Giant Pterosaurs Outcompeted Adults of Smaller Pterosaur Species: Study

Friday, October 29, 2021

An artist’s impression of hatchling pterosaurs. Image credit: Megan Jacobs.

Pterosaurs reached only modest sizes in the Triassic and Jurassic periods. By contrast, the Cretaceous period saw a trend toward large to giant size (2 m to over 6 m wingspans), and while small-medium (less than 1 m to 2 m wingspans) sized forms are known from the Early Cretaceous period they are rare in the Late Cretaceous epoch. It had been previously thought that the smaller species were outcompeted by newly-evolving birds, but, according to an analysis of new fossils from very small and small pterosaurs (less than 1 m wingspans) from the mid-Cretaceous Kem Kem Group of Morocco, it was actually the babies (flaplings) of giant pterosaurs who overshadowed their small adult rivals.

“Over the last 10 years or so, we’ve been doing fieldwork in Morocco’s Sahara Desert and have discovered over 400 specimens of pterosaurs from the Kem Kem Group, highly fossiliferous sandstones famous worldwide for the spectacular dinosaur Spinosaurus,” said Dr. Roy Smith, a paleontologist in the School of the Environment, Geography and Geosciences at the University of Portsmouth.

“We’d found some really big pterosaur jaws and also specimens that looked like smaller jaws — about the size of a fingernail — but these tiny pterosaur remains could have just been the tips of big jaws so we had to do some rigorous testing to find out if they were from a small species or from tiny juveniles of large and giant pterosaurs.”

In their research, Dr. Smith and colleagues examined five small jaw fragments and a neck vertebra of mid-Cretaceous pterosaurs.

“By looking at the paper-thin section of the bones under a microscope, I could tell that they were from juveniles as the bone was fast growing and didn’t have many growth lines,” said Dr. Anusuya Chinsamy-Turan, a researcher in the Department of Biological Sciences at the University of Cape Town.

“We also examined the surface of the bones and found they had a rippled texture.”

“This was further evidence they were the bones of immature individuals as mature pterosaur bones have an incredibly smooth surface once they are fully formed.”

The paleontologists also inspected the jaws and found that the number of tiny holes where nerves come to the surface for sensing their prey, known as foramina, were the same in the small jaws and the big jaws.

“This was more proof we were looking at the jaws of juveniles because if the specimens were just the tip of a jaw, there would be a fraction of the number of foramina,” Dr. Smith said.

“What really surprised me about this research is that the feeding ecology of these magnificent flying animals is more like that of crocodiles than of birds,” said Professor David Martill, a researcher in the School of the Environment, Geography and Geosciences at the University of Portsmouth.

“With birds, there will be perhaps 10 different species of different sizes alongside a river bank — think kingfisher, little bittern, little egret, heron, goliath heron or stork for a large European river. There are several species all feeding on slightly different prey. This is called niche partitioning.”

“Crocodiles on the other hand are much less diverse. On the river Nile, hatchling crocodiles feed on insects, and as they grow they change their diet to small fish, then larger fish and then small mammals, until a big adult Nile croc is capable of taking a zebra.”

“There are lots of different feeding niches, but they are all occupied by one species at different stages of its life history. It seems that pterosaurs did something rather similar, occupying different niches as they grew — a much more reptilian rather than avian life strategy.”

“It’s likely that the juvenile pterosaurs were feeding on small prey such as freshwater insects, tiny fishes and amphibians. As they grew they could take larger fishes — and who knows — the biggest pterosaurs might have been capable of eating small species of dinosaurs, or the young of large dinosaur species.”

The study was published in the journal Cretaceous Research.


Roy E. Smith et al. Small, immature pterosaurs from the Cretaceous of Africa: implications for taphonomic bias and palaeocommunity structure in flying reptiles. Cretaceous Research, published online October 16, 2021; doi: 10.1016/j.cretres.2021.105061


Laura Dern Teases Jurassic Park Reunion: We Had an Extraordinary Time

Thursday, October 28, 2021

Laura Dern cannot wait for audiences to see the Jurassic Park trio reunite in Jurassic World: Dominion.

Next year, Jurassic Park fans will have the pleasure of seeing the original trio, Doctors Alan Grant, Ian Malcolm and Ellie Sattler, reunite for Jurassic World: Dominion. Well, Laura Dern is just as excited as we all are, and cannot wait for audiences to bask in the contemporary brilliance Michael Crichton message, and director Colin Trevorrow's vision.

"Well, I'm so excited. We had an extraordinary time all being together and back together. I feel really excited and privileged to be part of something that in its core, you know, was environmental messaging thanks to [book author] Michael Crichton long ago."

Specific plot details for Jurassic World: Dominion are being kept under wraps, which includes how the trio of franchise heroes, Dr. Ian Malcolm, Dr. Alan Grant and Dr. Ellie Sattler (who will be played once again by Jeff Goldblum, Sam Neill, and Laura Dern respectively) are being brought back into the prehistoric fray. With the last movie in the ongoing franchise, Jurassic World: Fallen Kingdom, ending with several different species of dinosaur now let loose upon the world, it's likely that Jurassic World: Dominion will find the legacy characters brought in to help stop the prehistoric beasts and tackle the dinosaur threat alongside Jurassic World leads Bryce Dallas Howard and Chris Pratt.

Director Colin Trevorrow returns to the director's chair, and has teased how critical the original cast of characters will be to the events of Jurassic World: Dominion. "They are such big characters in the film. It's not a cameo," the filmmaker said earlier this year. "They're in the whole movie, so I think it'll be difficult to market the film without revealing them because they're all over it. I think that their roles are just as big as Chris and Bryce's are. So it's really a story that is two parallel lines that are getting closer and closer together until they collide. The thing that I could do that would show the most respect to these characters is put them on an adventure together and not just have them sit around. I don't want them commenting on what's going on. I want him to be in it. So that's what we did."

Trevorrow has even revealed that, so entwined are the three actors to their respective Jurassic Park characters, that they have even assisted in providing dialogue for the upcoming sequel. "These people have so many attributes, so many things about themselves that are just like Alan Grant and Ellie Sattler and Claire Dearing," Trevorrow explained. "It didn't end at the end of the shoot day. It didn't end on the weekend. We would write dialogue together and find ways to make sure that all of these actors, who are so deeply associated with this specific set of characters that they've played, not just felt their characters were respected but dug into who they are now."

Delayed by a year thanks to the ongoing global circumstances, Jurassic World: Dominion is now scheduled for theatrical release on June 10, 2022, by Universal Pictures. This comes to us courtesy of ET.


Jurassic Park Roars With New Stern Pinball Machine

Monday, October 25, 2021

Stern releases a brand new pinball machine that allows players to explore Isla Nublar and confront the iconic dinosaurs from 1993's Jurassic Park.

Fans of Steven Spielberg and Michael Crichton's classic sci-fi action film can now venture into the dinosaur-filled depths of Isla Nublar with Stern's new Jurassic Park pinball machine.

A new trailer highlights the pinball machine's gameplay and its references to the original Jurassic Park movie. According to the description, "With the volcano on the island erupting and threatening to destroy everything in its path, it is the player’s mission to rescue park staff, evacuate and recapture dinosaurs, and escape before it’s too late! Players will experience heart-pounding excitement right from the start in this action-packed pinball adventure filled with suspense, twists, and turns around every flip."

The machine features an interactive, custom sculpted Tyrannosaurus rex head that releases additional balls into play alongside a Stegosaurus fast ramp and Pteranodon jump ramp. Players can also battle against a Spinosaurus by smashing a captive ball and trap velociraptors in their enclosed cage through precision shooting. The trailer states, "players will experience heart-pounding excitement right from the start in this action-packed pinball adventure filled with suspense, twists, and turns around every flip."

Stern described the machine as "easy-to-setup." It stated, "Jurassic Park Pin is affordable, reliable, built to last, and engineered with genuine Stern commercial-quality parts." The pinball machine's cabinet features "dynamic, high definition, hand-drawn artwork" and "fast flowing metal ramps, lightning quick spinners, and kinetically satisfying physical drop targets will provide players with an adrenalized game experience packed with unmatched action and fun." The machine also incorporates John Williams's iconic theme music, high-definition graphics and animations on a LCD display. Stern states that the pinball machine's design reduces energy usage, increases reliability and only requires simplified servicing. The Jurassic Park pinball machine is currently available for purchase on the company's official website for a price of $4,599.

Spielberg's film adaptation of Crichton's novel of the same name was released in 1993 and starred Sam Neill, Jeff Goldblum, Richard Attenborough and Laura Dern. Upon its release, it became the highest-grossing film up to that time, surpassing the box office sales of E. T. the Extra-Terrestrial, and won three Academy Awards in 1994 -- Best Sound Editing, Best Sound Mixing and Best Visual Effects.

Neill, Goldblum and Dern are all set to reprise their roles in the upcoming Jurassic World: Dominion, joining Chris Pratt and Bryce Dallas Howard in the final instalment of director Colin Trevorrow's Jurassic World trilogy. The film is set to be released on June 10, 2022.

Source: / YouTubeStern

First Dinosaur Era Crab Discovered – Fully Preserved in 100-Million-Year-Old Amber

Monday, October 25, 2021

Artistic reconstruction of Cretapsara athanata: The immortal Cretaceous spirit of the clouds and waters. Credit: Artwork by Franz Anthony, courtesy of Javier Luque (Harvard University).

Fossils trapped in amber provide a unique snapshot of the anatomy, biology, and ecology of extinct organisms. The most common fossils found in amber, which is formed from resin exuded from tree bark, are land-dwelling animals, mainly insects. But on very rare occasions scientists discover amber housing an aquatic organism.

In a study published on October 20, 2021, in Science Advances an international team of researchers describe the first crab from the Cretaceous dinosaur era preserved in amber. The study used micro CT to examine and describe Cretapsara athanata, the oldest modern-looking crab (approximately 100 million years old) and the most complete fossil crab ever discovered. It is rivalled in completeness by the mysterious Callichimaera perplexa, a very distant relative nicknamed the platypus of the crab world. Callichimaera’s stunning preservation included soft tissues and delicate parts that rarely fossilize. Both Cretapsara and Callichimaera are new branches in the crab tree of life that lived during the Cretaceous Crab Revolution, a period when crabs diversified worldwide and the first modern groups originated while many others disappeared.

Cretapsara athanata: The first crab in amber from the dinosaur era. Credit: Xiao Jia (Longyin Amber Museum)

True crabs, or Brachyura, are an iconic group of crustaceans whose remarkable diversity of forms, species richness, and economic importance have inspired celebrations and festivals worldwide. They’ve even earned a special role in the pantheon of social media. True crabs are found all around the world, from the depths of the oceans, to coral reefs, beaches, rivers, caves, and even in trees as true crabs are among the few animal groups that have conquered land and freshwater multiple times.

The crab fossil record extends back into the early Jurassic, more than 200 million years ago. Unfortunately, fossils of nonmarine crabs are sparse and largely restricted to bits and pieces of the animals carapace – claws and legs found in sedimentary rocks. That is until now with the discovery of Cretapsara athanata. “The specimen is spectacular, it is one of a kind. It’s absolutely complete and is not missing a single hair on the body, which is remarkable,” said lead author Javier Luque, postdoctoral researcher in the Department of Organismic and Evolutionary Biology, Harvard University.

3D mesh of C. athanata Luque gen. et sp. nov. holotype LYAM-9. (A to E) 3D mesh extracted from reconstructed micro-CT data in VGSTUDIO MAX, remeshed in MeshLab, and visualized using Autodesk Maya: (A) dorsal, (B) ventral, (C) right lateral, (D) oblique postero-dorsal, (E) oblique antero-ventral views, showing the claws of equal size and four pairs of slender legs similar in shape and size, with P5 slightly smaller than the other legs. (F and G) Details of the dorsal (F) and ventral (G) carapace, showing details of the large eyes and orbits, small antennae, and a small, acute outer orbital spine [(F) thick arrow], two small anterolateral spines (F, thin arrows), a posterolateral margin bearing at least four small and equidistant tubercles (F, small arrows), straight posterior margin, slender coxae of the pereopods, a typical heterotreme eubrachyuran sternum (G), and a reduced and folded pleon with the first pleonites dorsally exposed. Left fifth pereopod digitally reattached. bcg, branchiocardiac groove; ca, carpus; cg, cervical groove; cx, coxa; da, dactylus; ib, ischiobasis; ma, manus or palm of claw; P1, claws or chelipeds; P2 to P5, pereopods or walking legs 2 to 5; po, pollex or fixed finger cheliped propodus; pr, propodus. Credit: Images and figure by Elizabeth Clark and Javier Luque. Used in journal.

A group of scientists led by co-lead author Lida Xing, China University of Geosciences, Beijing, made micro CT scans of the fossil, which is housed in the Longyin Amber Museum in Yunnan, China. The scans created a full three-dimensional reconstruction of the exquisite preservation of the animal allowing Luque, Xing, and their team to see the complete body of the animal including delicate tissues, like the antennae and mouthparts lined with fine hairs. Shockingly they discovered the animal also had gills.

“The more we studied the fossil, the more we realized that this animal was very special in many ways,” said Luque. Cretapsara is remarkably modern-looking – superficially resembling some shore crabs found today – unlike most crabs during the mid-Cretaceous era which looked quite different from modern crabs. Yet, the animal was entombed in Cretaceous amber and the presence of well-developed gills indicated an aquatic to semi-aquatic animal. Aquatic animals are rarely preserved in tree resins that become amber. Crabs previously found in amber are by the handful and belong to a living group of tropical land and tree-dwelling crabs known as Sesarmidae from the Miocene (15 million years ago). How then, the researchers asked, did a 100 million year old aquatic animal become preserved in tree amber, which normally houses land-dwelling specimens?

1. C. athanata Luque gen. et sp. nov., a modern-looking eubrachyuran crab in Burmese amber. (A to D) Holotype LYAM-9. (A) Whole amber sample with crab inclusion in ventral view. (B) Close-up of ventral carapace. (C) Whole amber sample with crab inclusion in dorsal view. (D) Close-up of dorsal carapace. White arrows in (B) and (D) indicate the detached left fifth leg or pereopod. Credit: Images and figure by Javier Luque and Lida Xing

Gills allow aquatic animals to breathe in water. But crabs have successfully and independently conquered land, brackish water, and fresh water at least twelve times since the dinosaur era. In doing so their gills evolved to include lung-like tissue allowing them to breathe both in and out of the water. Cretapsara however, had no lung tissue, only well-developed gills indicating the animal was not completely land dwelling. “Now we were dealing with an animal that is likely not marine, but also not fully terrestrial,” Luque said. “In the fossil record, nonmarine crabs evolved 50 million years ago, but this animal is twice that age.”

The team’s phylogenetic studies show that carcinization (the evolution of true crab-looking forms) had actually already occurred in the most recent common ancestor shared by all modern crabs more than 100 million years ago. Cretapsara bridges the gap in the fossil record and confirms that crabs actually invaded land and fresh water during the dinosaur era, not during the mammal era, pushing the evolution of nonmarine crabs much further back in time.

The researchers hypothesize that Cretapsara, measuring at five millimeters in leg span, was a juvenile crab of a freshwater to amphibious species. Or, that the animal is perhaps a semi-terrestrial juvenile crab migrating onto land from water as occurs to the iconic Christmas Island red crabs where land dwelling mother crabs release their babies into the ocean, which later swarm out of the water back onto land. They further hypothesize that like the crabs found in amber from the Miocene, Cretapsara could have been a tree climber. “These Miocene crabs are truly modern looking crabs and, as their extant relatives, they live in trees in little ponds of water,” said Luque, “these arboreal crabs can get trapped in tree resin today, but would it explain why Cretapsara is preserved in amber?”

Luque’s research is centered on understanding why things evolve into crabs, and their evolution and diversification over time leading to the modern forms seen today. “This study is pushing the timing of origin of many of these groups back in time. Every fossil we discover challenges our preconceptions about the time and place of origin of several organisms, often making us look further back in time,” Luque said.

The study is part of a National Science Foundation funded project with Luque, Professor Javier Ortega-Hernández and postdoctoral researcher Joanna Wolfe, both in the Department of Organismic and Evolutionary Biology, Harvard University, and Professor Heather Bracken-Grissom, Florida International University.

The researchers chose the name Cretapsara athanata, which means the immortal Cretaceous spirit of the clouds and waters, to honor the Cretaceous, during which this crab lived, and Apsara, a spirit of the clouds and waters in South and Southeast Asian mythology. The species name is based on “athanatos”, immortal, referring to its lifelike preservation as if ‘frozen in time’ in the time capsule that is amber.


Reference: “Crab in amber reveals an early colonization of non-marine environments during the Cretaceous” by Javier Luque, Lida Xing, Derek E. G. Briggs, Elizabeth G. Clark, Alex Duque, Junbo Hui, Huijuan Mai and Ryan C. McKellar, 20 October 2021, Science Advances. DOI: 10.1126/sciadv.abj5689

Author’s Statement: The studied fossil, deposited in the Longyin Amber Museum (LYAM), Yunnan Province, China, comes from a batch of commercial “raw” (dull, unpolished) amber pieces collected by local miners and sold to a vendor at an amber jewelry market in Myitkyina on May 12, 2015. The polished piece containing the fossil studied was acquired by LYAM from the vendor’s mineral store in Tengchong, China, on August 10, 2015. We acknowledge the existence of a sociopolitical conflict in northern Myanmar and have limited our research to material predating the 2017 resumption of hostilities in the region. We hope that conducting research on specimens collected before the conflict and acknowledging the situation in the Kachin State will serve to raise awareness of the current conflict in Myanmar and the human cost behind it.


5 Of The Best Dinosaur Books For Adults And Kids

Monday, October 25, 2021

We've put together a list of the best books on dinosaurs we think you should read.

If there are young children in your family, the chances are that one of them will go through a dinosaur phase at some point. Or maybe you’re still in your dinosaur phase yourself (and who could blame you? Dinosaurs are cool).

Either way, a dinosaur book is a great gift for yourself or a loved one. Not only is it educational, it will give you some astounding facts you can share with your friends.

We’ve put together a list of our pick of the best dinosaur books for adults and kids that will teach all sorts of things you didn’t know, from how they behaved to whether they really looked like the scaly lizards of Jurassic Park.

Or, for more ideas to add to your reading list, check out the best science books or the best science books for kids.

The Age Of Dinosaurs: The Rise And Fall Of The World’s Most Remarkable Animals

Steve Brusatte

Many young dinosaur fans dream of being a dinosaur hunter one day, and to uncover a fossil that turns out to be a brand new species. The Age of Dinosaurs allows them to put themselves in those shoes.

Prof Steve Brusatte is a palaeontologist at the University of Edinburgh, and in this book he gives an insider view into life hunting dinosaurs, including the story of discovering the tyrannosaur ‘Pinocchio rex’ (Qianzhousaurus).

And, of course, he also tells the story of the life of the dinosaurs throughout their full 150-million-year history.

Tyrannosaurus Rex: A Pop-up Guide To Anatomy

Dougal Dixon

This beautiful book will take you inside the very skull of a T. rex with stunning illustrations and pop-ups. You and your dinosaur-loving kids are invited to imagine watching the dissection of the first fully preserved T. rex specimen.

What anatomical features would you see inside its body, and what could this teach you about the way it behaved?

Dictionary Of Dinosaurs

Matthew G Baron

Do you know a young palaeontologist in the making? If they want to be a real expert, they’ll need to know about all kinds of dinosaurs, from Archaeopteryx to Zephyrosaurus (Okay, I looked that one up).

Dictionary of Dinosaurs covers not only the famous favourites, but many of the lesser known species, too. Each comes with information about the species, an illustration, and a comparison with the size of an average human. An added bonus is a pronunciation guide for the Latin names – no more arguing over whether it’s di-plod-o-cus or di-ploh-doc-us.

All Yesterdays: Unique And Speculative Views Of Dinosaurs And Other Prehistoric Animals

Darren Naish, John Conway and CM Kosemen

What did the dinosaurs look like? You might expect them to look like the enormous, scaly lizards of Jurassic Park – and this is definitely a common belief. But more recent discoveries have revealed that these prehistoric monsters may not have looked as we were led to believe.

You’ve probably heard that some dinosaurs had feathers – but did you know that we can tell what colour some of them were? And they weren’t just drab greens and greys, either. Some dinosaurs were red, blue, black or even iridescent. Then, of course, there’s the fact that bones are preserved much better than soft tissue. Could they have had wattles, like chickens or turkeys, or a keratinous ridge on their head like cassowaries?

All Yesterdays argues against the ‘shrink-wrapping’ approach that many representations of dinosaurs take, showing so little muscle under the skin that the overall structure of the skeleton can still be seen. Modern animals don’t look like that – why should prehistoric ones?

Locked In Time: Animal Behaviour Unearthed In 50 Extraordinary Fossils

Dean R Lomax

We know a lot about dinosaurs: when and where they lived, how big they were, how they died, and how they evolved into birds. And, of course, we can figure out a few things about how they behaved – this one had the teeth of a meat-eater, whereas that one can only have eaten plants. It’s hard to imagine that we could know much more about how they lived than that.

But, amazingly, we can. In Locked In Time, palaeontologist Dean Lomax takes us on a tour of 50 fossils of dinosaurs and other prehistoric animals that were preserved in the middle of their lives, from dinosaurs sitting on their eggs like birds to mammoths caught in a fight to the death.


Mussaurus patagonicus: Early Jurassic Herbivorous Dinosaurs Lived in Age-Segregated Herds

Saturday, October 23, 2021

Reconsturction of Mussaurus patagonicus herd. Image credit: Jorge Gonzalez.

Paleontologists have analyzed an exceptional fossil assemblage from the Laguna Colorada Formation in Patagonia, Argentina, that includes 193-million-year-old (Early Jurassic period) skeletal remains and eggs of the early sauropodomorph dinosaur Mussaurus patagonicus, ranging from embryos to fully-grown adults.

“People already knew that in the Late Jurassic and Cretaceous, the large herbivore dinosaurs exhibited social behavior — they lived in herds and had nesting spots,” said Dr. Jahandar Ramezani, a researcher in the Department of Earth, Atmospheric and Planetary Sciences at MIT.

“But the question has always been, when was the earliest time for such herding behavior?”

Dr. Ramezani and colleagues examined the fossilized skeletal remains of 80 individuals and over 100 eggs of Mussaurus patagonicus from the Laguna Colorada Formation of southern Patagonia.

“Such a preserved site was bound to provide us with a lot of information about how early dinosaurs lived,” said Dr. Diego Pol, a paleontologist at CONICET.

The paleontologists found that most of the eggs were arranged into clusters of between eight and 30 eggs.

X-ray imaging of five of these clusters revealed that eggs contained embryos of Mussaurus patagonicus and were arranged in two to three layers within trenches, suggesting that they were contained within nests within a common breeding ground.

The researchers analyzed the size and type of bone tissue of the skeletal remains to determine the ages of the fossilized individuals.

They identified a cluster of 11 juveniles aged less than a year old, two adults that were found together and nine individuals that were older than juveniles but younger than adults.

They suggest that the presence of age-specific clusters of individuals in the same location could indicate that Mussaurus patagonicus lived in herds throughout their lives but primarily associated with others their own age within herds.

“The young were not following their parents in a small family structure. There’s a larger community structure, where adults shared and took part in raising the whole community,” Dr. Ramezani said.

Specimens of Mussaurus patagonicus collected from the Laguna Colorada Formation, Patagonia, Argentina. Image credit: Pol et al., doi: 10.1038/s41598-021-99176-1.

The team dated ancient sediments among the fossils and determined that the herd of Mussaurus patagonicus dates back to around 193 million years ago, during the early Jurassic period.

The results represent the earliest evidence of social herding among dinosaurs — about 40 million years earlier than other records of dinosaur herding.

“We’ve now observed and documented this earliest social behavior in dinosaurs,” Dr. Ramezani said.

“This raises the question now of whether living in a herd may have had a major role in dinosaurs’ early evolutionary success. This gives us some clues to how dinosaurs evolved.”

The authors suspect that two other types of early dinosaurs — Massospondylus from South Africa and Lufengosaurus from China — also lived in herds around the same time.

If multiple separate lines of dinosaurs lived in herds, they believe the social behavior may have evolved earlier, perhaps as far back as their common ancestor, in the Late Triassic epoch, shortly before an extinction event wiped out many other animals.

“Now we know herding was going on 193 million years ago,” Dr. Ramezani said.

“This is the earliest confirmed evidence of gregarious behavior in dinosaurs. But paleontological understanding says, if you find social behavior in this type of dinosaur at this time, it must have originated earlier.”

paper on the findings was published in the journal Scientific Reports.


D. Pol et al. 2021. Earliest evidence of herd-living and age segregation amongst dinosaurs. Sci Rep 11, 20023; doi: 10.1038/s41598-021-99176-1


Paleontologists Find Fossils of New Lizard and Fish Species in Arkansas

Saturday, October 23, 2021

An illustration of Sciroseps pawhuskai. Image credit: Brian Engh.

Two new species — the small skink Sciroseps pawhuskai and the pycnodontiform fish Anomoeodus caddoi — that lived during the Early Cretaceous Period have been identified from fossils found in the Holly Creek Formation in southwest Arkansas.

While Arkansas is not traditionally considered a fertile source of Early Cretaceous fossils, the Trinity Group of the Holly Creek Formation has been unusually rich in them, including dinosaur tracks.

The area was inhabited by a wide variety of freshwater and land animals, including long-necked dinosaurs, large carnivores, raptor-like carnivores and armored dinosaurs.

It also provided a wide assortment of fossilized bones and teeth of much smaller creatures, such as sharks, fish, frogs, lizards, turtles and crocodilians.

“We present a new species of pycnodont fish, Anomoeodus caddoi, a likely relative of Texasensis, that existed in the waters of the ancient coastal plain,” said Dr. Celina Suarez, a paleontologist in the Department of Geosciences at the University of Arkansas at Fayetteville, and colleagues.

“And the new lizard Sciroseps pawhuskai, belonging to the paramacellodid-cordylid grade that dominated herpetofaunas of the North American Aptian-Albian, represented by one of the most complete mandibles known from the North American Early Cretaceous.”

“The Holly Creek Formation is interesting because few fossils have been described in publications, even though it has produced dinosaur fossils in the past,” added Dr. Joseph Frederickson, a paleontologist and director of the Weis Earth Science Museum at the University of Wisconsin Oshkosh Fox Cities Campus.

“Formations like these help us better understand how the continent was connected and the diversity of animals alive during the Early Cretaceous epoch.”

The team confirms that North America did not have as wide a variety of species in the Early Cretaceous epoch as it did in the Late Cretaceous epoch, roughly 70 million years ago.

The majority of fauna found in the Holly Creek Formation is similar to fauna found throughout North America at the same time.

What caused increased diversity of life between the Early and Late Cretaceous epochs?

According to the team, plate tectonics, which created mountains in the west, and climate changes, which drove rising sea levels, led to increased geographic isolation among similar species, spurring evolutionary changes in separated populations.

“When habitats are fragmented it can cause evolutionary changes,” Dr. Suarez said.

“One way this and other discoveries from the Cretaceous of North America can help us understand the modern world is how climate change can affect evolution of animals, be it extinction or the origination of new species.”

“Given that the Cretaceous was a period of rapidly warming and cooling worlds, understanding these time periods is important for understanding how future warming worlds will react to climate change.”

The study was published in the journal PeerJ.


C.A. Suarez et al. 2021. A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA. PeerJ 9: e12242; doi: 10.7717/peerj.12242


Australia's Oldest Dinosaur Was a Peaceful Vegetarian, Not a Fierce Predator

Saturday, October 23, 2021

Credit: Anthony Romilio, Author provided

Ipswich, about 40 kilometers west of Brisbane, seems an unlikely place to find dinosaur fossils. Yet the area has produced the oldest evidence of dinosaurs in Australia.

A fresh look at these fossils now reveals they aren't what they first seemed, and it's prompting us to reconsider how the story of Australia's dinosaurs began.

In research published today in Historical Biology, we reanalyse a sequence of 220-million-year-old tracks from the Ipswich Coal Measures, thought to have belonged to a carnivorous dinosaur.

We show they actually belonged to an early sauropodomorph—a distant relative of the plant-eating sauropods that roamed the planet much later, during the Jurassic and Cretaceous periods. This is the first time fossil evidence of early sauropodomorphs has been found in Australia.

Subterranean dinosaur tracks

The Ipswich area was once the principal source of coal for Queensland. Its suburbs including Ebbw Vale, New Chum and Swanbank were dotted with underground mines during the late 1800s and the first half of the twentieth century.

These mining operations involved the creation of deep shafts and tunnels, from which miners could access deposits of coal sandwiched between other layers of rock. Some tunnels would descend hundreds of meters below the surface.

The coal would be removed from the seam by hand, and pillars were left in its place to support the ceiling of the resulting underground "room." It was difficult and dangerous work.

Fossilised plant remains found in association with the tracks provide a fascinating window into the world of Australia’s first dinosaurs. The highly diverse flora comprised a dense groundcover of ferns, cycad-like plants and horsetails that grew under a canopy of gingko, voltzialean conifers and seed-ferns (corystosperms), like this Dicroidium dubium. Credit: Steven Salisbury, Author provided

In 1964, miners working at the Rhondda colliery in New Chum made a startling discovery. As they removed the coal from a seam they were following 213 meters below the surface, a series of giant, three-toed tracks became exposed in the ceiling of the mine shaft. For the miners, it was as if a dinosaur had just walked over their heads.

These tracks remain the oldest-known dinosaur fossils in the entire continent. They'd been made by a dinosaur walking across a layer of swampy vegetation, which would be extracted as coal 220 million years later. Buried under fine silt and mud, they'd been preserved as natural casts.

It had been assumed some type of predatory dinosaur made the tracks. The only problem was the footprints were reportedly about 40–46 centimeters long. This would suggest the track-maker was just under 2m high at the hips.

This isn't necessarily large for a theropod such as Allosaurus fragillis, which was about this size. Tyrannosaurus rex was even bigger, with a hip height of about 3.2m.

But the tracks found in Ipswich were created during the Late Triassic about 220 million years ago—65 million years before Allosaurus and 150 million years before T. rex. And fossil evidence from around the world indicates theropods of a larger size didn't appear until the start of the Early Jurrasic Period, 200 million years ago.

Was something unusual afoot in Australia during the Late Triassic?

As part of a broader review of Australian dinosaur tracks, we decided to take a closer look at the Rhondda colliery tracks. The mine has long been closed, so the original tracks are no longer accessible, but archival photographs and a plaster cast are held at the Queensland Museum.

Hypothetical reconstruction of the Ipswich sauropodomorph dinosaur, alongside an 3D orthographic image of one of the fossilised tracks form the Rhondda colliery, with a 1.8m person for scale. Credit: Anthony Romilio

Dispelling the myth of the 'Triassic terror'

Using the photos and cast, we created a 3D digital model of the track to allow a more detailed comparison with other dinosaur tracks from around the world.

Our study revealed two important things. First, the footprints were not as big as initially reported. Excluding drag marks and other unrelated surface features, they are close to 32–34cm long (not 40–46cm as previously documented).

Second, the shape of the footprints and the sequence in which they were made is more consistent with early sauropodomorphs. Sauropodomorphs were the distant relatives of the lumbering sauropods of the Late Jurassic and subsequent Cretaceous Period.

The towering Triassic terror of the Ipswich Coal Measures was no more. In its place was a peaceful plant-eater.

The remains of early sauropodomorph dinosaurs have been found in Upper Triassic rocks, aged between 220 million and 200 million years, in continental Europe, Argentina, Brazil and South Africa.

And by the start of the Jurassic, 200 million years ago, they had achieved a near global distribution, with fossils in North America, China and Antarctica. This isn't surprising, given the continents at the time were still connected in a single landmass called Pangaea.

Our new interpretation of the Rhondda colliery tracks shows early sauropodomorphs lived in Australia, too, and that Australia's first dinosaurs were friendlier than we thought.

Source: / Provided by The Conversation

Terropterus xiushanensis: Fossils of Giant Sea Scorpion Found in China

Tuesday, October 12, 2021

Life reconstruction of Terropterus xiushanensis. Image credit: Dinghua Yang.

A new genus and species of mixopterid eurypterid (sea scorpion) has been identified from several fossil specimens found in the Xiushan Formation, China.

Terropterus xiushanensis lived approximately 435 million years ago during the Llandovery epoch of the Silurian period.

The ancient marine creature belongs to a family of sea scorpions called Mixopteridae.

“Eurypterids, or sea scorpions, are an important group of mid-Paleozoic chelicerate arthropods whose evolution and paleoecological significance have attracted much attention in recent years,” said Professor Bo Wang from the Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment at the Chinese Academy of Sciences and colleagues.

“One of the most remarkable eurypterid families is Mixopteridae, whose members are quite large and superficially scorpion-like eurypterids bearing highly specialized anterior appendages.”

“Their second, and especially the third, pair of prosomal limbs are enlarged and very spiny. These limbs were presumably used for prey-capture, and analogies can be drawn with the ‘catching basket’ formed by the spiny pedipalps of whip spiders among the arachnids.”

“Our knowledge of these bizarre animals is limited to only four species in two genera described 80 years ago: Mixopterus kiaeri from Norway, Mixopterus multispinosus from New York, Mixopterus simonsoni from Estonia, and Lanarkopterus dolichoschelus from Scotland.”

“All are Silurian in age and come exclusively from the ancient continent of Laurussia, which constrains our knowledge of the morphological diversity, geographical distribution and evolutionary history of the group.”

Terropterus xiushanensis represents the first mixopterid from the ancient supercontinent of Gondwana as well as the oldest known mixopterid.

Specimens and reconstruction drawing of Terropterus xiushanensis: (a) appendages II-VI, holotype; (b) reconstruction drawing of Terropterus xiushanensis, dorsal and ventral views; (c) close-up of appendage V; (d) joint 5 or 6 of appendage III, paratype; (e) joint 5 or 6 of appendage III, paratype; (f) coxae, paratype; (g) genital operculum and the genital appendage, paratype. Scale bars – 5 mm in (a), (d), (f), and (g); 2 mm in (e); 1 mm in (c). Image credit: Wang et al., doi: 10.1016/j.scib.2021.07.019.

The species was relatively large, reaching up to 1 m (3.3 feet) in length, and had a ‘particularly enlarged prosomal limb III, characterized by a unique arrangement of spines.’

It likely played an important role of top predators in the Silurian marine ecosystem when there were no large vertebrate competitors.

“The paleogeographical distribution of mixopterids was rather limited until now and no examples of this group have been previously discovered in Gondwana,” the paleontologists said.

“Our first Gondwanan mixopterid — along with other eurypterids from China and some undescribed specimens — suggests an under-collecting bias in this group.”

“Future work, especially in Asia, may reveal a more cosmopolitan distribution of mixopterids and perhaps other groups of eurypterids.”

The study was published in the journal Science Bulletin.


Han Wang et al. 2021. First mixopterid eurypterids (Arthropoda: Chelicerata) from the Lower Silurian of South China. Science Bulletin 66 (22): 2277-2280; doi: 10.1016/j.scib.2021.07.019