Saturday, February 15, 2014

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.
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


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