Oldest Sea Monster Babies Found; Fossil Shows Reptiles Had Live Birth

Mother ichthyosaur died while giving birth, scientist says.

by Christine Dell’Amore

The oldest embryos of a Mesozoic marine reptile have been unearthed in China, pre-dating the previous record by ten million years, a new study says.

The 248-million-year-old fossil from the Mesozoic era (252 to 66 million years ago) reveals an ichthyosaur baby inside its mother (orange) and another stuck in her pelvis (yellow). A third embryo discovered nearby suggests it was stillborn; scientists believe the mother died during a difficult labor.

The narrow, eel-like ichthyosaur belongs to the genusChaohusaurusand is the oldest known species of the group.

The findings were published February 12 in the journal PLOS ONE.

It’s not just the age of the Mesozoic-era discovery that is surprising; it’s the shattering of the belief that ichthyosaurs—also dubbed sea monsters—gave birth in water, not on land.

The scientists reached their conclusion because the fossil showed the offspring emerging head-first—a behavior found only in animals that give birth on land. The babies of most marine animals, such as whales and sea cows, are born tail-first…

(read more: National Geo)

fossil images: Ryosuke Motani, UC DAVIS; Chaohusaurus illustration by Nobu Tamura