Researchers have uncovered the first child dinosaurs from Australia. The bones have been found at a number of websites alongside the south coast of Victoria and close to the outback city of Lightning Ridge in New South Wales. A number of the bones are so tiny, they probably come from animals that had died whereas they have been nonetheless of their eggs. Barely bigger bones from Victoria come from animals that had not too long ago hatched however have been in all probability nest-bound.
The analysis was carried out by palaeontologists from the Palaeoscience Research Centre on the College of New England and the Australian Opal Centre in Lightning Ridge. The bones come from small-bodied ornithopod dinosaurs—two legged herbivores that weighed roughly 20kg when full grown—much like Weewarrasaurus, which was just lately found by members of the identical group at Lightning Ridge. By comparability, the newborn dinosaurs have been solely about 200g after they died, much less that the burden of a cup of water.
Whereas the eggs themselves weren’t discovered, researchers used growth rings within the bones, just like the rings in a tree trunk, to estimate the animal’s age. “Age is often estimated by counting progress rings, however, we could not do that with our two smallest specimens, which had misplaced their inside element,” says Justin Kitchener, a Ph.D. scholar on the University of New England, who additionally led the examine.
100 million years in the past, when these animals have been being born, Australia was a lot nearer to the poles. Southeastern Australia would have been between 60°S and 70°S, equal to modern-day Greenland. Though the climate at these latitudes was comparatively warmer than they’re at the moment, like some Antarctic penguins, these dinosaurs would have endured long darkish winters and probably burrowed or hibernated to outlive.
As a result of they’re so delicate, egg shell and tiny bones not often survive to turn into fossils. “Now we have examples of hatchling-sized dinosaurs from near the North Pole, however that is the primary time we have seen this type of factor anyplace within the Southern Hemisphere,” says Dr. Phil Bell, a University of New England palaeontologist who recognised the importance of the tiny bones from Lightning Ridge. “It is the primary clue we have had about the place these animals have been breeding and elevating their younger.”