Chinese Dinosaur Embryo Fossils Are Oldest Found So Far
The oldest fossilised dinosaur embryos found so far have been discovered by palaeontologists in China. With several of the embryos petrified at different stages of development, it offers a rare insight into exactly how dinosaurs developed inside eggs.
Also exciting is that the embryos appear to contain organic matter that hasn’t been fossilised, which would be the oldest organic material ever found from a terrestrial vertebrate. The fossils — which are thought to be either Massospondylus or Lufengosaurus — have been dated as being between 190 and 197 million years old, the Lower Jurassic period.
Embryos can be difficult to study when fossilised because they tend to be inside eggs, but in this case more than 200 bones from several different animals were found among the remains of broken eggshells.
"The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism," writes Robert Reisz, the study’s lead author.
Spectroscopic analysis of the bones also revealed the presence of preserved organic matter, the oldest so far found from a land-based vertebrate. The material — thought to be collagen — will be useful in determining the exact species of these embryos.
Both Massospondylus and Lufengosaurus are both sauropods, the clade of huge dinosaurs known for long necks and long tails. The most famous sauropod is probably Diplodocus. The embryos show a “consistently rapid rate of growth throughout development”, which could imply how all sauropods grew during the embryonic stage.
The findings have been published in Nature.
image: LufengosaurusJason Quinn/Wikimedia Commons/CC BY 3.0
credit: Jason Quinn/ Wikimedia Commons/CC BY 3.0