An ancient Mesozoic marine reptile fossil may depict the oldest-known live birth.
The Ichthyosaurs were large marine reptiles that adapted to live in the water as opposed to on land, a PLOS news release reported.
This new fossil depicts a Chaohusaurus, which is the oldest known Mesozoic marine reptile that swam the seas 248 million years ago. The partial skeleton (which was discovered in China) could depict a live ancient birth.
The fossil included three embryos and neonates; one was still inside the stomach, one had half of its body outside of the body, and one may have already been born.
The "headfirst birth posture" of the half-born baby suggests this type of dinosaur may have given birth on land as opposed to in the water.
"The reason for this animal dying is likely difficulty in labor," Ryosuke Motani, lead study author and a paleobiologist at the University of California, Davis. Motani told LiveScience."Obviously, the mother had some complications,"
The specimen could be the "oldest fossil embryos of Mesozoic marine reptile," the news release reported. The fossil is about 10 million years older than specimens that have been previously recorded. The finding also suggest live births in reptiles occurred earlier in history than researchers previously believed, the news release reported.
"The study reports the oldest vertebrate fossil to capture the 'moment' of live-birth, with a baby emerging from the pelvis of its mother. The 248-million-year old fossil of an ichthyosaur suggests that live-bearing evolved on land and not in the sea," Ryosuke Motani from the University of California, Davis, said in the news release.
"This land-style of giving birth is only possible if they inherited it from their land ancestors," Motani told Live Science. "They wouldn't do it if live birth evolved in water."
