The babies of a ferocious group of carnivorous dinosaurs, which included T-rex, were large, fully toothed and clawed and ‘born’ to kill, according to the analysis of newly uncovered embryonic remains.
The fossils come from two species in the group of tyrannosaurs, the apex predators in Asia and North America during the Cretaceous towards the end of the dinosaur period.
The remains consist of a 3 cm long, 77 million year old jaw that was found in Montana and possibly belonged to a species called Daspletosaurus and an approximately 72 million year old claw that was excavated in the Alberta province of Canada is and probably from an Albertosaurus.
Both were slightly smaller cousins of the most famous tyrannosaurus, the Tyrannosaurus rex, which was more than 12 meters long and weighed about seven tons.
T-rex was up to 12 meters long and weighed seven tons Pic: AP
The fossils indicated that it was larger than any other known dinosaur baby – one meter long or the size of a medium-sized dog – and hatched from the enormous eggs that may be 43 cm (17 inches) long from the largest dinosaur eggs currently familiar.
The jawbone has characteristic tyrannosaurus characteristics, including a deep groove on the inside and a prominent chin.
Edinburgh University paleontologist Greg Funston, lead author of the research published in the Canadian Journal of Earth Sciences, said the scientists were amazed at how similar the embryonic bones were to older tyrannosaurs and young adults, noting that the jaws boast functional teeth.
“While we can not get a complete picture, what we can see looks a lot like adults,” Funston said.
The fossils indicate that the babies were larger than previously thought: Dr. Greg Funston
It appears that tyrannosaurs, Funston added, ‘were born ready to hunt, and they already had some of the major adaptations that gave tyrannosaurs their powerful bite.
“So it is likely that they were able to hunt fairly quickly after birth, but we need more fossils to tell exactly how fast it was.”