Quirks & Quarks

Tetrapod Fossils Fill in the Blank

A gap in the fossil record covering the time when our ancestors moved from water to land, is partially filled in by fossils from Nova Scotia.

A gap in the fossil record of our ancestors' evolution is filled in

Artist's conception of Ichthyostega, an aquatic tetrapod from before the fossil gap. (Nobu Tamura, cc-by-sa-3.0)
For decades, paleontologists have been puzzled by a 30-million-year gap in the fossil record, covering exactly the period when our ancestors, the tetrapods, moved onto land and went from being four-finned fish-like creatures, to four-footed terrestrial walking animals.

But recent discoveries, including finds from Blue Beach, Nova Scotia, on the Bay of Fundy, are starting to fill in the gap. Dr. Jason Anderson, a vertebrate paleontologist and Associate Professor of Veterinary Anatomy at the University of Calgary, and his colleagues, have studied a large trove of fossil bones collected largely by citizen scientists from Nova Scotia.

They determined that there were several species of previously unknown tetrapods, both aquatic and terrestrial forms, roaming the area about 350 million years ago, right at the critical gap in the fossil record.

Related Links

Paper in PLoS One
- PLoS Integrative Paleontologists blog