A study examining the developmental origins of the frog urostyle--a unique structure that evolved around 200 million years ago and forms during metamorphosis as the tail regresses and axial locomotion in larve gives way to limb-driven movement in adults--finds that thyroid hormone-mediated ossification and expansion of the hypochord, a key component of the urostyle, played a major role in tail loss, rearrangement of the dorsal aorta, and evolution of the body plan of Anura, the amphibian order that includes frogs.
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Article # 19-17506: "Ontogeny of the anuran urostyle and the developmental context of evolutionary novelty," by Gayani Senevirathne, Stephanie Baumgart, Nathaniel Shubin, James Hanken, and Neil H. Shubin.
MEDIA CONTACT: Neil Shubin, University of Chicago, IL; tel: 773-834-7472; e-mail: < nshubin@uchicago.edu >
Proceedings of the National Academy of Sciences