Oldest dinosaur embryo fossils discovered in China
Palaeontologists working in China have unearthed the earliest collection of fossilized dinosaur embryos to date. The trove includes remains from many individuals at different developmental stages, providing a unique opportunity to investigate the embryonic development of a prehistoric species.
Robert Reisz, a palaeontologist at the University of Toronto in Mississauga, Canada, and his colleagues discovered the sauropodomorph fossils in a bone bed in Lufeng County that dates to the Early Jurassic period, 197 million to 190 million years ago. The site contained eggshells and more than 200 disarticulated bones â the oldest known traces of budding dinosaurs, the researchers report online today in Nature1.
âMost of our record of dinosaur embryos is concentrated in the Late Cretaceous period,â says David Evans, curator of vertebrate palaeontology at the Royal Ontario Museum in Toronto. âThis [study] takes a detailed record of dinosaur embryology and pushes it back over 100 million years.â
But it is not just the age of the fossils that is notable, the researchers say. Spectroscopic analysis of bone-tissue samples from the Chinese nesting site revealed the oldest organic material ever seen in a terrestrial vertebrate. That was surprising because the fossilized femur bones were delicate and porous, which made them vulnerable to the corrosive effects of weathering and groundwater, says Reisz.
âThat suggests to us that other dinosaur fossils might have organic remains,â he says. âWe just havenât looked at them in the right ways.â
