A fossil discovered in China has paleontologists baffled. This prehistoric marine reptile lived long before the dinosaurs and probably gave birth to live young like some snakes and lizards do today.
It has been named Dinocephalosaurus and was first discovered in 2002. With its long winding neck, it probably fed on fish and squid that lived in the shallow seas of what is now Southern China 250 million years ago.
A newly discovered fossil appeared to have a miniature replica of the same animal inside it. The mini Dinocephalosaurus was positioned in such a way, a forward-facing position, that the researchers exclude it to have been eaten. Instead, the researchers believe that the fossil shows that Dinocephalosaurus gave birth to live young.
What makes this odd is that this marine lizard is a precursor to a group of animals that do not give birth to live young today. It is the first case of live births in this group that includes birds, crocodiles, and dinosaurs. The find pushes back evidence of reproduction in this group of animals 50 million years.
The researchers speculate that this was a unique survival strategy for this specific species. Giving birth to live young probably increases their chances of survival, since a marine reptile that lays eggs must step up onto the dangerous beach and then run the risk of dying, it may simply have been a necessary development for their survival.
Jun Liu et al. Live birth in an archosauromorpha reptile. Nature Communications February 14, 2017. DOI: 10.1038 / ncomms14445