A new study, published in the journal Scientific Reports revealed that researchers have discovered the first baby dinosaurs from Australia. According to the study, the bones were uncovered at a number of sites along the south coast of Victoria and near the outback town of Lightning Ridge in New South Wales.
The research, which was carried out by palaeontologists from the Palaeoscience Research Centre at the University of New England and the Australian Opal Centre in Lightning Ridge, said that some of the bones were so tiny that it looked like those were of animals that had died in their eggs itself. However, some of the slightly larger bones, which were recovered from Victoria, indicated that those belonged to animals that had recently hatched but were probably nest-bound.
Very similar to Weewarrasaurus
The study findings suggested that the bones come from small-bodied ornithopod dinosaurs. When fully grown, these two-legged herbivores weighed roughly 20kg and are very similar to Weewarrasaurus, which was recently discovered by members of the same team at Lightning Ridge. When compared, the researchers found that the baby dinosaurs weighed only about 200g when they died, which was less than the weight of a cup of water.
The scientists used growth rings in the bones to get an estimate of the animal's age as the eggs were not found. Justin Kitchener, who led the study said, "Age is usually estimated by counting growth rings, but we couldn't do this with our two smallest specimens, which had lost their internal detail."
"To get around this, we compared the size of these bones with the size of growth rings from the Victorian dinosaurs. This comparison confidently places them at an early growth stage, probably prior to, or around the point of hatching," Kitchener, a PhD student at the University of New England, added.
Reveals first clue about breeding and raising their kids
The study noted that Australia was much closer to the poles when these animals were born some 100 years ago. Southeastern Australia would have been between 60°S and 70°S, which is equivalent to modern-day Greenland.
When compared to today's temperature, the scientists believe that though the climate was relatively warmer at those said latitudes, the dinosaurs would have experienced long dark winters and possibly hibernated or burrowed for their survival. The study also suggested that the eggshell and those tiny bones rarely became a fossil as those dinosaurs were extremely delicate.
Dr Phil Bell, a University of New England palaeontologist who recognised the significance of the tiny bones from Lightning Ridge, said, "We have examples of hatchling-sized dinosaurs from close to the North Pole, but this is the first time we've seen this kind of thing anywhere in the Southern Hemisphere. It's the first clue we've had about where these animals were breeding and raising their young."