There is a very faint dimple, “said Stirling nesbitt, lighting with a palm-sized fossil. Fossils, pelvic bones, belong to a creature called Teleocrater rhadinus. The elongated, 2-meter-long reptile, which lived 244 million years ago, was thought to have first appeared in the world about 10 to 15 million years ago.
A paleontologist at Virginia tech university in blacksburg, who tilted the bone toward the top of his head, illuminates a small dent in the fossil. The size of the dent corresponds to the size of the thumbprint, indicating the position of the leg bone suitable for the pelvis. In real dinosaurs, there was a complete hole in the hip socket, not just a depression. Dimples are like waving red flags: no, not dinosaurs.
The hole in the hip socket may help the dinosaur keep his legs under his body instead of spreading out like a crocodile’s leg. Until recently, the cave was one of the few features paleontologists used to identify whether they placed their hands on actual dinosaur specimens.
Another sign of no failure is a special depression on the top of the skull. Until the Teleocrater blew it. This creature was long before the dinosaurs, but it had dinosaur skulls.
The once-long list of “absolute dinosaurs” has been shrinking for decades, thanks to new discoveries by close relatives, such as the Teleocrater. Another feature was eliminated with the arrival of the Telecrater’s skull depression report in April 2017 (SN Online: 4/17/17).
Today, only a feature for the dinosaur is unique, it is living on earth about 165 million years of vast and diverse fauna, until some catastrophic asteroid and the combination of volcanic eruption destroyed except birds all the dinosaurs.
“I’m often asked what the definition of a dinosaur is,” said Randall Irmis, a paleontologist at the natural history museum in Utah. Ten to fifteen years ago, he said, scientists might have listed sixty functions. “The only thing to talk about is a full hole in the hip socket.”
Recently discovered dinosaur form, including with.
The richness of the dinosaurs that lived in the early and early stages of the dinosaurs was more than just a question of diagnostic features. It is shaking the long-term view of the dinosaur family tree.
For Nesbitt, all this turmoil places a more sacred cow on the chopping block: the uniqueness of dinosaurs.
“What is a dinosaur? He said. “This is essentially arbitrary.