Caelestiventus hanseni: Newly-Discovered Triassic Pterosaur Lived in Harsh Desert

Wednesday, August 15, 2018

Caelestiventus hanseni. Image credit: Michael Skrepnick / Brigham Young University.

Paleontologists have discovered what they say is a completely unexpected desert-dwelling pterosaur that lived in what is now Utah, the United States, about 210 million years ago. The discovery of this early pterosaur, reported in the journal Nature Ecology and Evolution, sheds new light on early pterosaur anatomy and development.

Pterosaurs were giant flying reptiles that flew over the heads of the dinosaurs. Soaring on skin wings supported by a single huge finger, they were the largest animals ever to take wing.

Originating in the Late Triassic epoch (around 215 million years ago), they thrived to the end of the Cretaceous period (66 million years ago).

Triassic pterosaurs are extraordinarily rare and are known exclusively from marine deposits in the Alps (Italy, Austria and Switzerland), except for Arcticodactylus cromptonellus from fluvial deposits in Greenland.

The new Triassic pterosaur is from the Saints & Sinners Quarry near Dinosaur National Monument in Utah.

Named Caelestiventus hanseni, the ancient flying reptile was comparatively large (wing span over 5 feet, or 1.5 m) and lived in harsh desert environments.

It is the only record of desert-dwelling non-pterodactyloid pterosaurs. It predates all known desert pterosaurs by more than 65 million years.

“We’re getting insights into the beginning of pterosaus. Ours shows that they’re extraordinarily diverse,” said Brigham Young University’s Dr. Brooks Britt.

A 3D-printed model of the Caelestiventus hanseni skull. Image credit: Nate Edwards / Brigham Young University.

Caelestiventus hanseni was found in sandstone so the bones were not crushed.

Rather than trying to extricate the thin bones from the sandstone, Dr. Britt and colleagues CT scanned the specimen and created 3D models of the bones for study.

“Most Triassic specimens consist of just a single bone: for example, a little phalanx from a finger or one vertebra from the neck,” Dr. Britt said.

“For this animal, we have the sides of the face and the complete roof of the skull, including the brain case, complete lower jaws and part of the wing.”

Caelestiventus hanseni’s 3D bones provide insights into the evolution of the earliest pterosaurs — especially the skull.

“These insights include the muscles attached and the nature of the teeth, which numbered about 112,” the paleontologists said.

“Furthermore, the skull roof preserves the impression of the brain, which reveals that even early pterosaurs had a poor sense of smell and well-developed vision.”

Caelestiventus hanseni is most closely related to Dimorphodon macronyx, known only from Lower Jurassic strata of Britain,” they said.

“This indicates that the family Dimorphodontidae originated in the latest Triassic and the lineage survived the Triassic-Jurassic mass extinction event.”

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Brooks B. Britt et alCaelestiventus hanseni gen. et sp. nov. extends the desert-dwelling pterosaur record back 65 million years. Nature Ecology & Evolution, published online August 13, 2018; doi: 10.1038/s41559-018-0627-y

Source: www.sci-news.com