Triopticus primus: Scientists Shed Light on Bizarre Dinosaur Having Bony Domed Head

Wednesday, October 11, 2017

A possible reconstruction of Triopticus based on the fragmentary remains and comparative anatomy. Illustration by Julio Lacerda

On the basis of a fossilized partial skull excavated in 1940 near Big Spring, Texas and then remained in drawer in a University of Texas paleontology collection, scientists have discussed about a bizarre dinosaur named Triopticus primus.

Around 228 million years back, this dinosaur used to live in a warm, lush region of West Texas. Factor that separates this dinosaur from others is its bony domed head, composed of thickened bone. As per scientists, other animal having such comparable craniums were dinosaurs known as pachycephalosaurs that were present around 90 million years back.

The researchers have found similarity in the internal structures of Triopticus and pachycephalosaurs skulls. Earlier, the researchers were confused as what for purpose pachycephalosaurs used their heads and now, they have same uncertainty for Triopticus.

Study’s lead researcher Michelle Stocker was of the view, “It’s difficult for us to say what the domed morphology would have been for or what would have ‘encouraged’ the evolution of this structure”.

Triopticus as per the researchers is an interesting example of evolutionary convergence as the unique body shapes found in many dinosaurs have evolved million of years back in the Triassic Period. According to the researchers, the dinosaur might have been around 10 feet long.

The researchers are not exactly clear on whether Triopticus walked on two legs or four and it is also known whether it ate plants or meat. The dinosaur was present when the very first dinosaurs were actually appearing.

Katharine Criswell, evolutionary biologist at University of Chicago, said that it is quite amazing to know that many of the iconic dinosaur features have arrived independently up to 100 million earlier in the distant reptilian cousins.

According to a report in CS Monitor by Eva Botkin-Kowacki, “Stocker and her colleagues came upon the skull when sorting through specimens collected across Texas by the Works Progress Administration in the late 1930s and early 1940s. “We were just going through the drawers and found this blob, essentially,” she recalls in a phone interview with The Christian Science Monitor”

New, but also familiar. When the paleontologists began to examine the skull, they quickly noticed the remarkable thickness of the roof of the skull. The dome-shaped skull struck them as particularly similar to those of animals that lived about 140 million years later: the pachycephalosaur dinosaurs.

Instead, the specimen was a relative of dinosaurs and crocodilians, Stocker says. And that means this is a prime example of convergent evolution, a process by which two different animals independently evolve a similar feature. The team dubbed the extinct animal, Triopticus primus, in a paper describing the specimen published Thursday in the journal Current Biology.

A report published in VOA NEWS informed, “In a warm, lush region of West Texas crisscrossed with rivers, a bizarre reptile roamed the Triassic Period landscape about 228 million years ago, boasting a bony domed head unlike almost any creature that ever appeared on Earth.”

Even the internal structure of Triopticus and pachycephalosaurs skulls was similar. There has been a long debate among paleontologists about how pachycephalosaurs used their heads, whether for head-butting like bighorn sheep, self-defense or some other purpose.

“It’s difficult for us to say what the domed morphology would have been for or what would have ‘encouraged’ the evolution of this structure,” said Virginia Tech paleontologist Michelle Stocker, who led the study published in the journal Current Biology.