犹他州出土绝种猪鼻龟化石

In the 250-million-year evolutionary history of turtles, scientists have seen nothing like the pig nose of a new species of extinct turtle discovered in Grand Staircase-Escalante National Monument by a team from the Natural History Museum of Utah. "It's one of the weirdest turtles that ever lived," said Joshua Lively, who described the new species today in the Journal of Vertebrate Paleontology. "It really helps add to the story emerging from dinosaur research carried out at the Natural History Museum of Utah."

Lively studied the fossil as part of his master's thesis at the University of Utah. He is now a doctoral student at the University of Texas at Austin.

The extinct turtle was about 2 feet long from head to tail. Its streamlined shell was adapted for living in a riverine environment. When it was alive, 76 million years ago during the Cretaceous Period, Southern Utah looked more like present-day Louisiana. The climate was wet and hot, and the landscape was dominated by rivers, bayous and lowland flood plains.

It lived alongside tyrannosaurs, armored ankylosaurs, giant duck-billed dinosaurs such as Gryposaurus and Parasaurolophus, and other dinosaurs that left abundant fossil remains in the Upper Cretaceous Kaiparowits Formation of Southern Utah. But those fossil beds also hold the remains of many crocodilians, turtles, lizards and amphibians that don't look much different from their modern relatives.

Unlike any turtle ever found, the broad snout of the newly discovered species has two bony nasal openings. All other turtles have just one external nasal opening in their skulls; the division between their nostrils is only fleshy.