This month’s Nature’s cover story of the discovery in southeast Poland of “a trackway and an isolated footprint that were made by early four-legged land vertebrates (tetrapods) almost 400 million years ago” – 18 million years older than the earliest known tetrapod body fossils, and 10 million years older than the oldest elpistostegids – prompts The Guardian’s Adam Rutherford to celebrate “the intellectual freedom of pure research that led them to this awesome discovery.” Which may be a bit of a stretch… The BBC report provides some of the detail from the Nature story. An earlier Guardian article adds
Ahlberg and his co-authors, mainly from the Polish Geological Institute in Warsaw, say their findings highlight how little we know of the earliest history of land vertebrates. They write that the prints “force a radical reassessment of the timing, ecology and environmental setting of the fish-tetrapod transition, as well as the completeness of the body fossil record”.
The trackway and analysis
And a detailed footprint