Ancient reptile birth preserved in fossil

Feb 12, 2014
This is the maternal specimen with three embryos. Credit: PLoS ONE, Ryosuke Motani, doi:10.1371/journal.pone.0088640

Ichthyosaur fossil may show the earliest live birth from an ancient Mesozoic marine reptile, according to a study published February 12, 2014 in PLOS ONE by Ryosuke Motani from the University of California, Davis, and colleagues.

Ichthyosaurs were giant marine reptiles that evolved from land reptiles and moved to the water. Scientists report a new fossil specimen that belongs to Chaohusaurus (Reptilia, Ichthyopterygia), the oldest of Mesozoic that lived approximately 248 million years ago. The was recovered in China and may show a live birth. The maternal skeleton was associated with three embryos and neonates: one inside the mother, another exiting the pelvis-with half the body still inside the mother-and the third outside of the mother. The headfirst birth posture of the second embryo indicates that in may have taken place on land, instead of in the water, as some studies have previously suggested.

The new specimen may contain the oldest fossil embryos of Mesozoic marine reptile, about 10 million years older than those indicated on previous records. The authors also suggest that live births in land reptiles may have appeared much earlier than previously thought.

Dr. Motani added, "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."

Explore further: Subsurface structures discovered at prehistoric archaeological site

More information: Motani R, Jiang D-y, Tintori A, Rieppel O, Chen G-b (2014) Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils. PLoS ONE 9(2): e88640. DOI: 10.1371/journal.pone.0088640

Related Stories

Oldest pregnant lizard fossil discovered

Jul 22, 2011

(PhysOrg.com) -- A new paper published in Naturwissenschaft reveals a fossil from 120 million years ago that proves that some lizards were not laying eggs but rather giving birth to live y ...

'Pregnant plesiosaur' examined

Aug 11, 2011

A paper to be published on August 12, 2011 in Science reveals that Dr. F. Robin O'Keefe of Marshall University in Huntington, W.Va. and Dr. Luis Chiappe, Director of the Natural History Museum's Dinosaur Institute, have d ...

Warm-blooded sea reptiles of the Jurassic

Jun 10, 2010

(PhysOrg.com) -- New evidence shows that reptiles roaming the oceans at the time of the dinosaurs could maintain a constant body temperature well above that of the surrounding water.

Recommended for you

Study suggests that dinosaurs were warm-blooded

15 hours ago

Dinosaurs grew as fast as your average living mammal, according to a research paper published by Stony Brook University paleontologist Michael D'Emic, PhD. The paper, to published in Science on May 29, is ...

Fossil ancestor shows sharks have a bony past

16 hours ago

Most people know that sharks have a distinctive, all-cartilage skeleton, but now a fossil from Western Australia has revealed a surprise 'missing link' to an earlier, more bony form of the fish.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.