WASHINGTON (Reuters) – Scientists have for the first time found original remains from the group of wild meat-eating dinosaurs that include T. rex – fossil jaw bones and claw that show the These babies of recorded size look very much like adults and were born “ready” to hunt.
The fossils, the researchers said Tuesday, represented two species from the group known as tyrannosaurs, the APEX predators in Asia and North America during the Cretaceous period near the end of the dinosaur age.
The bones indicated that these were larger than other known dinosaur babies – three feet (1 meter) long, or the size of a medium sized dog – and born from the largest possible eggs, and perhaps taller than 17-inches (43-cm) long the largest currently known dinosaur eggs.
The jawbone about 77 million years old, about 1.2 inches (3 cm) long, was found in Montana and may belong to a species called Daspletosaurus. The moon-shaped claw, which is about 72 million years old, came from the Alberta region of Canada and may belong to a species called Albertosaurus.
Both are slightly smaller cousins of Tyrannosaurus rex. The most well-known tyrannosaurs had a top of 40 feet (12 meters) in length and weighed 8 tons.
The hook has unique tyrannosaur features, including a deep inner groove 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 young and adult tyrannosaurs and gave they noticed that there were active teeth in the jaws.
“So while we can’t get a complete picture, what we see looks very similar to the adults,” said Funston.
Tyrannosaurs, Funston, “seems to have been born ready to hunt, with some of the key changes already that have given tyrannosaurs powerful bites. So it looks like they were able to hunt quickly after they were born, but we need more fossils to tell how fast that was. ”
Reporting by Will Dunham, Editing by Rosalba O’Brien