Cryolophosaurus in Japan

Cryolophosaurus is now on exhibit at the Fukui Paleontological Museum in Japan for a Gondwana dinosaur exhibit. This is only the fourth full cast of Cryo in the world (and the most up to date), with the others found at Augustana College in Rock Island, IL (the first mounted skeleton), War Memorial Museum in Auckland, New Zealand, and the Royal Belgian Institute of Natural Sciences. These cast are made by Research Casting International. The Australian Museum in Sydney also has a cast, but I am not sure if it is just a skull or the full body.

Last spring before I moved to Colorado I was employed at Augustana College (the best job I have ever had btw - great boss and good working environment, I really miss it) and worked on Cryo on a daily basis. We packed up all of the new elements that had been prepared since it was originally cast nearly 10 years ago and sent them to RCI so a new, more accurate postcranial skeleton could be made for the Japanese exhibit. I am happy to see this picture of it now on exhibit! I really like the way they have it mounted. It is nice to not see a lot of heavy armature under the skeleton. I thought I would pass the picture on since not many of us will have a chance to see the exhibit. But if anyone does make it over there, I would love to see your pictures!

You can read the official monograph on Cryolophosaurus for free here (PDF).


© ReBecca K. Hunt-Foster, Picture © Chisako Sakata - used with permission

Kryostega collinsoni

I was excited to see this press release the other day. We had this specimen on display at Augustana for a long time (below center) and then I shipped it off to Chris Sidor last year for him to work on. So it is exciting to see Kryostega collinsoni getting some press!


ScienceDaily (2008-09-12) -- Paleontologists have found a previously unknown amphibious predator that probably made the Antarctica of 240 million years ago something less than a hospitable place.

The species, named Kryostega collinsoni, is a temnospondyl, a prehistoric amphibian distantly related to modern salamanders and frogs. K. collinsoni resembled a modern crocodile, and probably was about 15 feet in length with a long and wide skull even flatter than a crocodile's.

In addition to large upper and lower teeth at the edge of the mouth, temnospondyls often had tiny teeth on the roof of the palate. However, fossil evidence shows the teeth on the roof of the mouth of the newly found species were probably as large as those at the edge of the mouth.

"Its teeth, compared to other amphibians, were just enormous. It leads us to believe this animal was a predator taking down large prey," said Christian Sidor, a University of Washington associate professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture at the UW.

Sidor is lead author of a paper describing the new species published in the September issue of the Journal of Vertebrate Paleontology. Co-authors are Ross Damiani of Staatliches Museum für Naturkunde Stuttgart in Germany and William Hammer of Augustana College in Rock Island, Ill.

The scientists worked from a fossilized piece of the snout of K. collinsoni, analyzing structures present in more complete skulls for other temnospondyl species that had similar size characteristics.

"The anatomy of the snout tells us what major group of amphibian this fossil belonged to," Sidor said.

Teeth at the edge of the mouth, as well as on the palate roof, were clearly visible, and the presence of structures similar to those that allow fish and amphibians to sense changes in water pressure led the researchers to conclude that the species was aquatic.

The fossilized piece of snout also contains a nostril, which aided the scientists in judging proportions of the head when comparing it to other fossils. They estimated the skull was about 2.75 feet long and perhaps 2 feet across at its widest point.

"Kryostega was the largest animal in Antarctica during the Triassic," Sidor said.

The term "Kryostega" translates to 'frozen' and 'roof,' which refer to the top of the skull. The scientists named the species for James Collinson, a professor emeritus of Earth sciences at Ohio State University who made important contributions to the study of Antarctic geology.

Hammer collected the fossil in 1986 from an Antarctic geological layer called the Fremouw Formation. He has studied a number of other Antarctic fossils, including dinosaurs, collected at about the same time, and so the temnospondyl fossil was not closely examined until the last couple of years.

At the time K. collinsoni was living, all the world's land was massed into a giant continent called Pangea. The area of Antarctica where the fossil was found was near what is now the Karoo Basin of South Africa, one of the richest fossil depositories on Earth.

Sidor noted that in the early Triassic period, from about 245 million to 251 million years ago, just before the period that produced the K. collinsoni fossil, it appears that Antarctica and South Africa were populated by largely the same species. While Antarctica was still colder than much of the world, it was substantially warmer than it is today, though it still spent significant periods in complete darkness.

By the middle of the Triassic period perhaps only half the species were the same, he said, and in the early Jurassic period, around 190 million years ago, unique early dinosaur species were appearing in Antarctica.

"It could be that these animals were adjusting to their local environment by then, and we are seeing the results of speciation occurring at high latitude," Sidor said. "Here we have really good evidence that Antarctic climate wasn't always the way it is today. During the Triassic, it was warmer than it is today – it was warmer globally, not just in Antarctica."

This work was funded in part by the National Science Foundation and the Alexander von Humboldt Foundation." [link]

Scientists find 245 million-year-old burrows of land vertebrates in Antarctica

Transantarctic Vertebrate Paleontology Project Member Chris Sidor will have the 'cover article' in the months Journal Of Vertebrate Paleontology "Tetrapod burrows from the Triassic of Antarctica" (pages 277-284). You can read more about Dr. Sidor's work in Antarctica here.

From the press release:

For the first time paleontologists have found fossilized burrows of tetrapods – any land vertebrates with four legs or leglike appendages – in Antarctica dating from the Early Triassic epoch, about 245 million years ago.

The fossils were created when fine sand from an overflowing river poured into the animals' burrows and hardened into casts of the open spaces. The largest preserved piece is about 14 inches long, 6 inches wide and 3 inches deep. No animal remains were found inside the burrow casts, but the hardened sediment in each burrow preserved a track made as the animals entered and exited.

In addition, scratch marks from the animals' initial excavation were apparent in some places, said Christian Sidor, a University of Washington assistant professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture at the UW.

"We've got good evidence that these burrows were made by land-dwelling animals rather than crayfish," said Sidor, who is lead author of a paper describing the find, which is being published in the June edition of The Journal of Vertebrate Paleontology.

Co-authors are Molly Miller, a geology professor at Vanderbilt University, and John Isbell, a geosciences professor at the University of Wisconsin-Milwaukee. The work was funded by the National Science Foundation.

Fossils of tetrapod bones from later in the Triassic period have been found in a section of Antarctica called Victoria Land, but the fossil burrows predate those bone fossils by at least 15 million years, Sidor said.

The fossilized burrows were collected in 2003 and 2005-06 from the Fremouw Formation at Wahl Glacier and from the Lashly Formation at Allan Hills, both toward the outer edges of Antarctica.

Despite the absence of fossil bones, the burrows' relatively small size prompted Sidor to speculate that their owners might have been small lizardlike reptiles called Procolophonids or an early mammal relative called Thrinaxodon.

Burrows, some containing tetrapod bones, have previously been excavated in South Africa, which is considered to be perhaps the world's richest fossil depository, and those burrows are nearly identical to the fossils unearthed in Antarctica. During the Triassic period, Antarctica and South Africa were connected as part of a supercontinent called Pangea.

Because even at that time Antarctica was substantially colder than South Africa, and because sea levels likely were higher than today, it is much rarer to find fossils there that date from as far back as the Early Triassic.

"Everywhere has a spotty fossil record, but Antarctica has an extremely spotty fossil record because it is difficult finding exposed rocks amid all the ice," Sidor said.

At the time the burrows were dug, Antarctica would have been ice free. However temperatures still would have been quite cold, since both areas where the burrows were found are within the Antarctic Circle and so experience at least one day a year of complete darkness.

"We have documented that tetrapods were burrowing, making dens in Antarctica, back in the Triassic," Sidor said. "There are lots of good reasons for burrowing at high latitudes, not the least of which is protection from the elements."

Also see "New Fossils Suggest Ancient Cat-sized Reptiles in Antarctica"

Fossil Friday

Todays fossil: Cryolophosaurus ellioti
This is the animal that I work on at Augustana College! While most of his remains that have been recovered are prepared, we still have several blocks of unprepared material, and this is what I work on.

The name Cryolophosaurus means "frozen crested reptile." The characteristic feature of this dinosaur is the large crest on the top of the skull, above the eyes. The nasal bones extend toward the back of the skull as ridges, and then join with the lacrimal bones to form a grooved crest which extends perpendicularly from the skull. Cryolophosaurus was discovered in the Jurassic Hanson Formation in the Transantarctic Mountains and represents the only theropod dinosaur to be found in Antarctica.
Read more about Cryolophosaurus: Transantarctic Vertebrate Paleontology Project website.
See more of my Cryolophosaurus pictures here.