A new fossil precursor of terrestrial vertebrates
This is a 380 million year old 'precursor' of the first vertebrates to leave water and move onto land. It has fore and hind limbs containing many of the bones present in human limbs, but in addition, bares jointed bones that also support fin webbing. It was discovered in western North America, and is being studied by researchers at UC Berkeley to not only help us better understand the sequence of anatomical and functional changes leading to land-living vertebrates, but also to reconstruct the ancient aquatic environments from which they evolved.
Image courtesy of Brian Swartz, Ph.D. candidate in Integrative Biology and with UCMP