Elpistostege and the origin of the vertebrate hand
© Mark Mawson/Getty
The complete fossil of a four-limbed fish, which existed around 374 million years ago, has provided a key piece of the evolutionary puzzle of how fins evolved into hands.
A team that included researchers from Flinders University in Australia used computed tomography imaging to reveal the bone structure in the pectoral fins of the 1.57-metre-long fossil of Elpistostege watsoni.
They found the species has both carpal wrist bones and parallel-aligned bones that resemble the start of fingers in the human hand, but these come together in the bony spines characteristic of the end of a fish fin.
The structure may have enabled the animal to support some of its weight while moving in shallow water or on land. It is the closest a fin has come in structure to the separate digits seen in four-limbed animals.
- Nature 579, 549–554 (2020). doi: 10.1038/s41586-020-2100-8
|Université du Québec à Rimouski (UQAR), Canada||0.50|
|Flinders University, Australia||0.43|
|South Australian Museum, Australia||0.07|