Oldest giant ichthyosaur discovery

Cymbospondylus

From ScienceDaily, 23 December 2021, by the Natural History Museum of Los Angeles County in the USA:

The two-meter skull of a newly discovered species of giant ichthyosaur, the earliest known, is shedding new light on the marine reptiles’ rapid growth into behemoths of the Dinosaurian oceans, and helping us better understand the journey of modern cetaceans (whales and dolphins) to becoming the largest animals to ever inhabit the Earth.

While dinosaurs ruled the land, ichthyosaurs and other aquatic reptiles (that were emphatically not dinosaurs) ruled the waves, reaching similarly gargantuan sizes and species diversity. Evolving fins and hydrodynamic body-shapes seen in both fish and whales, ichthyosaurs swam the ancient oceans for nearly the entirety of the Age of Dinosaurs.

“Ichthyosaurs derive from an as yet unknown group of land-living reptiles and were air-breathing themselves,” says lead author Dr. Martin Sander, paleontologist at the University of Bonn and Research Associate with the Dinosaur Institute at the Natural History Museum of Los Angeles County (NHM). “From the first skeleton discoveries in southern England and Germany over 250 years ago, these ‘fish-saurians’ were among the first large fossil reptiles known to science, long before the dinosaurs, and they have captured the popular imagination ever since.”

Excavated from a rock unit called the Fossil Hill Member in the Augusta Mountains of Nevada, the well-preserved skull, along with part of the backbone, shoulder, and forefin, date back to the Middle Triassic (247.2-237 million years ago), representing the earliest case of an ichthyosaur reaching epic proportions. As big as a large sperm whale at more than 17 meters (55.78 feet) long, the newly named Cymbospondylus youngorum is the largest animal yet discovered from that time period, on land or in the sea. In fact, it was the first giant creature to ever inhabit the Earth that we know of.

“The importance of the find was not immediately apparent,” notes Dr. Sander, “because only a few vertebrae were exposed on the side of the canyon. However, the anatomy of the vertebrae suggested that the front end of the animal might still be hidden in the rocks. Then, one cold September day in 2011, the crew needed a warm-up and tested this suggestion by excavation, finding the skull, forelimbs, and chest region.”

The new name for the species, C. youngorum, honors a happy coincidence, the sponsoring of the fieldwork by Great Basin Brewery of Reno, owned and operated by Tom and Bonda Young, the inventors of the locally famous Icky beer which features an ichthyosaur on its label.

In other mountain ranges of Nevada, paleontologists have been recovering fossils from the Fossil Hill Member’s limestone, shale, and siltstone since 1902, opening a window into the Triassic. The mountains connect our present to ancient oceans and have produced many species of ammonites, shelled ancestors of modern cephalopods like cuttlefish and octopuses, as well as marine reptiles. All these animal specimens are collectively known as the Fossil Hill Fauna, representing many of C. youngorum’s prey and competitors.

C. youngorum stalked the oceans some 246 million years ago, or only about three million years after the first ichthyosaurs got their fins wet, an amazingly short time to get this big. The elongated snout and conical teeth suggest that C. youngorum preyed on squid and fish, but its size meant that it could have hunted smaller and juvenile marine reptiles as well.

The giant predator probably had some hefty competition. Through sophisticated computational modeling, the authors examined the likely energy running through the Fossil Hill Fauna’s food web, recreating the ancient environment through data, finding that marine food webs were able to support a few more colossal meat-eating ichthyosaurs. Ichthyosaurs of different sizes and survival strategies proliferated, comparable to modern cetaceans’ — from relatively small dolphins to massive filter-feeding baleen whales, and giant squid-hunting sperm whales.

Co-author and ecological modeler Dr. Eva Maria Griebeler from the University of Mainz in Germany notes, “due to their large size and resulting energy demands, the densities of the largest ichthyosaurs from the Fossil Hill Fauna including C. youngourum must have been substantially lower than suggested by our field census. The ecological functioning of this food web from ecological modeling was very exciting as modern highly productive primary producers were absent in Mesozoic food webs and were an important driver in the size evolution of whales.”

Whales and ichthyosaurs share more than a size range. They have similar body plans, and both initially arose after mass extinctions. These similarities make them scientifically valuable for comparative study. The authors combined computer modeling and traditional paleontology to study how these marine animals reached record-setting sizes independently.

“One rather unique aspect of this project is the integrative nature of our approach. We first had to describe the anatomy of the giant skull in detail and determine how this animal is related to other ichthyosaurs,” says senior author Dr. Lars Schmitz, Associate Professor of Biology at Scripps College and Dinosaur Institute Research Associate. “We did not stop there, as we wanted to understand the significance of the new discovery in the context of the large-scale evolutionary pattern of ichthyosaur and whale body sizes, and how the fossil ecosystem of the Fossil Hill Fauna may have functioned. Both the evolutionary and ecological analyses required a substantial amount of computation, ultimately leading to a confluence of modeling with traditional paleontology.”

They found that while both cetaceans and ichthyosaurs evolved very large body sizes, their respective evolutionary trajectories toward gigantism were different. Ichthyosaurs had an initial boom in size, becoming giants early on in their evolutionary history, while whales took much longer to reach the outer limits of huge. They found a connection between large size and raptorial hunting — think of a sperm whale diving down to hunt giant squid — and a connection between large size and a loss of teeth — think of the giant filter-feeding whales that are the largest animals ever to live on Earth.

Ichthyosaurs’ initial foray into gigantism was likely thanks to the boom in ammonites and jawless eel-like conodonts filling the ecological void following the end-Permian mass extinction. While their evolutionary routes were different, both whales and ichthyosaurs relied on exploiting niches in the food chain to make it really big.

“As researchers, we often talk about similarities between ichthyosaurs and cetaceans, but rarely dive into the details. That’s one way this study stands out, as it allowed us to explore and gain some additional insight into body size evolution within these groups of marine tetrapods,” says NHM’s Associate Curator of Mammalogy (Marine Mammals), Dr. Jorge Velez-Juarbe. “Another interesting aspect is that Cymbospondylus youngorum and the rest of the Fossil Hill Fauna are a testament to the resilience of life in the oceans after the worst mass extinction in Earth’s history. You can say this is the first big splash for tetrapods in the oceans.”

C. youngorum will be permanently housed at the Natural History Museum of Los Angeles County, where it is currently on view.

Basilisk and motmot in Panama

This video says about itself:

Male Common Basilisk And Rufous Motmot Visit The Panama Fruit Feeder – May 20, 2021

A male Common Basilisk and a Rufous Motmot were both drawn to the buffet and the motmot does not seem interested in sharing the platform. Both of these visitors have a habit of being statue-still for portions of their time at the feeder. Note that this basilisk lost his tail at some point and it is slowly growing back in.

New dinosaurs, other fossils discovered

This 20 March 2021 video is called New Fossils and Paleontology- February 2021. About discoveries, from dinosaurs to Cambrian invertebrates.

4-year-old girl’s 220-million-year-old dinosaur footprint discovery

This 30 January 2020 video says about itself:

“Dino-mite” invention: Lily Wilder, 4, finds 215-million-year-old ‘two-footed’ dinosaur footprint

A girl from Wales has discovered a perfectly preserved 215-million-year-old dinosaur print, described as the ‘finest’ of its type found in 10 years.

Read more here.

Triassic marine reptile Atopodentatus

This 22 December 2020 video says about itself

The Triassic Reptile With “Two Faces”

Figuring out what this creature’s face actually looked like would take paleontologists years. But understanding this weird animal can help us shine a light on at least one way for ecosystems to bounce back from even the worst mass extinction.

Only Irish dinosaurs described

This December 2018 video says about itself:

Dinosaurs existed for over 170 million years and lived all over the Earth. You might expect to find fossil evidence of them everywhere you look, but only two dinosaur fossils have been found in Ireland.

Dr Mike Simms, Senior Curator of Natural History at National Museums Northern Ireland, explains why.

Read more on this story here.

From the University of Portsmouth in England:

Only dinosaurs found in Ireland described for the first time

November 26, 2020

Summary: The only dinosaur bones ever found on the island of Ireland have been formally confirmed for the first time by a team of experts. The two fossils are from two different dinosaurs, a four-legged plant-eater called Scelidosaurus and a two-legged meat-eater similar to Sarcosaurus.

The only dinosaur bones ever found on the island of Ireland have been formally confirmed for the first time by a team of experts from the University of Portsmouth and Queen’s University Belfast, led by Dr Mike Simms, a curator and palaeontologist at National Museums NI.

The two fossil bones were found by the late Roger Byrne, a schoolteacher and fossil collector, who donated them along with many other fossils to Ulster Museum. Analysis has confirmed they are from early Jurassic rocks found in Islandmagee, on the east coast of County Antrim.

Ulster Museum has announced plans to put them on display when it reopens after the latest rounds of restrictions are lifted.

Dr Simms, National Museums NI, said: “This is a hugely significant discovery. The great rarity of such fossils here is because most of Ireland’s rocks are the wrong age for dinosaurs, either too old or too young, making it nearly impossible to confirm dinosaurs existed on these shores. The two dinosaur fossils that Roger Byrne found were perhaps swept out to sea, alive or dead, sinking to the Jurassic seabed where they were buried and fossilised.”

The article, published in the Proceedings of the Geologists’ Association, is part of a larger project to document Jurassic rocks in Northern Ireland and draws on many fossils in Ulster Museum’s collections.

Originally it was assumed the fossils were from the same animal, but the team were surprised to discover that they were from two completely different dinosaurs. The study, employing the latest available technology, identified the type of dinosaur from which each came. One is part of a femur (upper leg bone) of a four-legged plant-eater called Scelidosaurus. The other is part of the tibia (lower leg bone) of a two-legged meat-eater similar to Sarcosaurus.

The University of Portsmouth team, researcher Robert Smyth, originally from Ballymoney, and Professor David Martill, used high-resolution 3D digital models of the fossils, produced by Dr Patrick Collins of Queen’s University Belfast, in their analysis of the bone fragments.

Robert Smyth said: “Analysing the shape and internal structure of the bones, we realised that they belonged to two very different animals. One is very dense and robust, typical of an armoured plant-eater. The other is slender, with thin bone walls and characteristics found only in fast-moving two-legged predatory dinosaurs called theropods.”

“Despite being fragmentary, these fossils provide valuable insight on a very important period in dinosaur evolution, about 200 million years ago. It’s at this time that dinosaurs really start to dominate the world’s terrestrial ecosystems.”

Professor Martill said: “Scelidosaurus keeps on turning up in marine strata, and I am beginning to think that it may have been a coastal animal, perhaps even eating seaweed, like marine iguanas do today.”

To find out when the fossils will go on display at the Ulster Museum follow @ulstermuseum on Twitter, @ulstermuseumbelfast on Facebook and @ulstermuseum on Instagram.

Titanosaur dinosaur infected by parasites

From New Scientist:

Ancient parasites in a titanosaur’s bones made it look like a zombie

20 November 2020

By Joshua Rapp Learn

Some of the oldest evidence of bone disease may have been caused by tiny 83-million-year-old parasites infecting a titanosaur, which are among the largest land animals that ever lived. This is the first discovery of parasites in a dinosaur bone.

“It’s a new kind of parasite,” says Aline Ghilardi at the Federal University of Rio Grande do Norte in Brazil. “We don’t have anything similar to it.”

This fossilised parasite was seen in a sample from a dwarf titanosaur.

Rubeosaurus, Styracosaurus, same dinosaur species?

This 13 November 2020 video says about itself:

Was “Rubeosaurus” Styracosaurus After All? YDAW Synapisode #6

New research came out this year with bearing upon everyone’s favorite centrosaurine(s), so here’s more than you probably wanted to know about parietals.

Triassic mammal-like reptile discovery in Arizona, USA

From Virginia Tech university in the USA:

New species of ancient cynodont, 220 million years old, discovered

November 4, 2020

Fossilized jaw bone fragments of a rat-like creature found at the Petrified Forest National Park in Arizona last year by a Virginia Tech College of Science Ph.D. candidate are in fact a newly discovered 220-million-year-old species of cynodont or stem-mammal, a precursor of modern-day mammals.

The finding of this new species, Kataigidodon venetus, has been published today in the journal Biology Letters by lead author Ben Kligman, a doctoral student in the Department of Geosciences.

“This discovery sheds light on the geography and environment during the early evolution of mammals,” Kligman said. “It also adds to evidence that humid climates played an important role in the early evolution of mammals and their closest relatives. Kataigidodon was living alongside dinosauromorphs and possibly early dinosaurs related to Coelophysis — a small bipedal predator — and Kataigidodon was possibly prey of these early dinosaurs and other predators like crocodylomorphs, small coyote-like quadrupedal predators related to living crocodiles.”

Kligman added that finding a fossil that is part of Cynodontia, which includes close cousins of mammals, such as Kataigidodon, as well as true mammals, from Triassic rocks is an extremely rare event in North America. Prior to Kligman’s discovery, the only other unambiguous cynodont fossil from the Late Triassic of western North America was the 1990 discovery of a braincase of Adelobasileus cromptoni in Texas. Note that 220 million years ago, modern-day Arizona and Texas were located close to the equator, near the center of the supercontinent Pangaea. Kataigidodon would have been living in a lush tropical forest ecosystem.

Kligman made the discovery while working as a seasonal paleontologist at Petrified Forest National Park in 2019. The two fossil lower jaws of Kataigidodon were found in the Upper Triassic Chinle Formation. Because only the lower jaws were discovered and are quite small — half an inch, the size of a medium grain of rice — Kligman only has a semi-picture of how the creature looked, roughly 3.5 inches in total body size, minus the tail.

Along with the jawbone fossils, Kligman found incisor, canine, and complex-postcanine teeth, similar to modern day mammals. Given the pointed shape of its teeth and small body size, it likely fed on a diet of insects, Kligman added. (Why are jaw fossils commonly found, even among small specimens? According to Kligman, the fossil record is “biased” toward only preserving the largest and most robust bones in a skeleton. The other smaller or more fragile bones — ribs, arms, feet — disappear.)

Kligman carried out fieldwork, specimen preparation, CT scanning, conception, and design of the study and drafting of the manuscript. He added that he and his collaborators only discovered the fossils were of a new species after reviewing the CT scan dataset of the jaws and comparing it to other related species.

“It likely would have looked like a small rat or mouse. If you were to see it in person you would think it is a mammal,” Kligman added. Does it have fur? Kligman and the researchers he worked with to identify and name the creature actually don’t know. “Triassic cynodonts have not been found from geological settings which could preserve fur if it was there, but later nonmammalian cynodonts from the Jurassic had fur, so scientists assume that Triassic ones did also.”

The name Kataigidodon venetus derives from the Greek words for thunderstorm, “kataigidos,” and tooth, “odon,” and the Latin word for blue, “venetus,” all referring to the discovery location of Thunderstorm Ridge, and the blue color of the rocks at this site. Kligman didn’t name the creature, though. That task fell to Hans Dieter-Sues, coauthor and curator of vertebrate paleontology at the Smithsonian National Museum.

Additional collaborators include Adam Marsh, park paleontologist at Petrified Forest National Park, who found the jaw fossils with Kligman, and Christian Sidor, an associate professor at the University of Washington’s Department of Biology. The research was funded by the Petrified Forest Museum Association, the Friends of Petrified Forest National Park, and the Virginia Tech Department of Geosciences.

“This study exemplifies the idea that what we collect determines what we can say,” said Michelle Stocker, an assistant professor of geosciences and Kligman’s doctoral advisor. “Our hypotheses and interpretations of past life on Earth depend on the actual fossil materials that we have, and if our search images for finding fossils only focuses on large-bodied animals, we will miss those important small specimens that are key for understanding the diversification of many groups.”

With Kataigidodon being only the second other unambiguous cynodont fossil from the Late Triassic found in western North America, could there be more new species out there waiting to be found?

Kligman said most likely. “We have preliminary evidence that more species of cynodonts are present in the same site as Kataigidodon, but we are hoping to find better fossils of them,” he added.

Triassic marine reptiles, new research

This video is called Newly discovered Triassic lizard could float underwater to pick off prey 2020 10 28.

From ScienceDaily:

Ancient marine predator had a built-in float

New 240 million-year-old species uncovered in China

October 28, 2020

About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. A short and flat tail, used for balance, helps identify it as a new species, according to research published in the Journal of Vertebrate Paleontology.

Paleontologists at the Chinese Academy of Scientists and Canadian Museum of Nature have analysed two skeletons from a thin layer of limestone in two quarries in southwest China. They identified the skeletons as nothosaurs, Triassic marine reptiles with a small head, fangs, flipper-like limbs, a long neck, and normally an even longer tail, probably used for propulsion. However, in the new species, the tail is short and flat.

“Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we’ve identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey,” says Dr Qing-Hua Shang from the Chinese Academy of Sciences, in Beijing.

The scientists have named the new species Brevicaudosaurus jiyangshanensis, from the Latin ‘brevi’ for ‘short,’ ‘caudo’ for ‘tail,’ and the Greek ‘sauros’ for ‘lizard.’ The most complete skeleton of the two was found in Jiyangshan quarry, giving the specimen its species name. It’s just under 60cm long.

The skeleton gives further clues to its lifestyle. The forelimbs are more strongly developed than the hind limbs, suggesting they played a role in helping the reptile to swim. However, the bones in the front feet are short compared to other species, limiting the power with which it could pull through the water. Most of its bones, including the vertebrae and ribs, are thick and dense, further contributing to the stocky, stout appearance of the reptile, and limiting its ability to swim quickly but increasing stability underwater.

However, thick, high-mass bones act as ballast. What the reptile lost in speed, it gained in stability. Dense bones, known as pachyostosis, may have made it neutrally buoyant in shallow water. Together with the flat tail, this would have helped the predator to float motionless underwater, requiring little energy to stay horizontal. Neutral buoyancy should also have enabled it to walk on the seabed searching for slow-moving prey.

Highly dense ribs may also suggest the reptile had large lungs. As suggested by the lack of firm support of the body weight, nothosaurs were oceanic nut they needed to come to the water surface for oxygen. They have nostrils on the snout through which they breathed. Large lungs would have increased the time the species could spend underwater.

The new species features a bar-shaped bone in the middle ear called the stapes, used for sound transmission. The stapes was generally lost in other nothosaurs or marine reptiles during preservation. Scientists had predicted that if a stapes was found in a nothosaur, it would be thin and slender like in other species of this branch of the reptilian family tree. However, in B. jiyangshanensis it is thick and elongate, suggesting it had good hearing underwater.

“Perhaps this small, slow-swimming marine reptile had to be vigilant for large predators as it floated in the shallows, as well as being a predator itself,” says co-author Dr. Xiao-Chun Wu from the Canadian Museum of Nature.