Our evolutionary timeline just leapt back an additional 40 million years into the past. Some new fossil trackways from the early Carboniferous of Australia have been interpreted as the first bone-fide "amniotes". This is the group of egg laying vertebrates which we belong to along, with all the other mammals, birds, and reptiles. These fossils are much earlier than previously thought possible and potentially turns our understanding of this event on its head. We take a look at these fossils and the implications, in particular that there could be loads of missing things out there yet to be found, including our own ancestors and distant relatives.

Figure from the study showing the fossil footprints slab, with details of fingers/toes and claws scrapping along the surface, and fossil rain drops.

The paper is "Earliest amniote tracks recalibrate the timeline of tetrapod evolution" by John Long and colleagues, published in Nature in May 2025. https://doi.org/10.1038/s41586-025-08884-5

Widescreen artwork: Marcin Ambrozik..