Young Tyrannosaur Feasted On 2 Baby Dinosaurs Before Dying, 75-Million-Year-Old Fossil Reveals

A new study on a 75 million-year-old fossil has revealed that a Gorgosaurus, a teenage Tyrannosaur, feasted on two baby dinosaurs before it died, BBC reported. Dr. Darla Zelenitsky from the University of Calgary, one of the study's lead scientists, explains that there is clear evidence that tyrannosaurs had a remarkably changed diet as they got older. 

"This is the first time that such well-preserved stomach contents have been found inside the skeleton of a large species of tyrannosaur," Darla Zelenitsky, the co-author of the study, said. It is "solid evidence that tyrannosaurs drastically changed their diet as they grew up," Ms Zelenitsky added. 

According to the study published in the journal Science Advances, the hind legs of two baby dinosaurs were found inside the tyrannosaur's stomach cavity. It was found that the gorgosaur was roughly seven years old and weighed 330 kilograms at the time of its death.

First stomach contents of a Tyrannosaur ever discovered.

Paleontologists reported on Dec 8 the discovery of a juvenile tyrannosaur called Gorgosaurus libratus with the partially digested drumsticks of two birdlike dinosaurs where its stomach once was.pic.twitter.com/ClcsrKSdcI

— Massimo (@Rainmaker1973) December 11, 2023

The researchers say the discovery suggests the juvenile gorgosaurus preyed on small, young dinosaurs, while the adult gorgosaurus attacked and ate very large plant-eating dinosaurs.

Ms Zelenitsky said, ''We now know that these teenage (tyrannosaurs) hunted small, young dinosaurs. These smaller, immature tyrannosaurs were probably not ready to jump into a group of horned dinosaurs, where the adults weighed thousands of kilograms.''

The two baby dinosaurs both belonged to the species called Citipes elegans and would have been younger than 1-year-old when the tyrannosaur hunted them down, the research said.

Ms Zelenitsky further explained, ''Tyrannosaurs are these large predatory species that roamed Alberta, and North America during the late Cretaceous. These were the iconic apex or top predators that we've all seen in movies, books, and museums. They walked on two legs (and) had very short arms.”

''It was a cousin of T. rex, which came later, 68 to 66 million years ago. T. rex is the biggest of the tyrannosaurs, Gorgosaurus was a little bit smaller, maybe full grown would have been 9, 10 meters (33 feet),'' she said, as per CNN.

The fossil was first discovered in Canada's Alberta Badlands in 2009 but was buried in rock and took several years to prepare for study.