New fossil evidence suggests tetrapods walked on land millions of years earlier than believed

Nature · Published 3 October 2026 Swipe more like this →

In short: For decades, scientists believed the first land-dwelling amniotes emerged in the mid-Carboniferous. However, new trackway discoveries in Australia reveal clawed footprints from the early Tournaisian, forcing a major recalibration of the evolutionary timeline. This shift suggests the origin of these pioneering creatures occurred deep in the Devonian period.

The transition from water to land is a cornerstone of vertebrate history, marking the shift from aquatic life to the emergence of the tetrapod crown group. This process was not a singular event but a complex sequence of evolutionary milestones. It began with the development of basic terrestrial movement in the tetrapod stem group and culminated in the rise of major lineages, including amphibians and amniotes. Amniotes, in particular, were transformative because they achieved complete reproductive independence from water, fueling unprecedented levels of biological diversity and disparity.

Previously, researchers relied on a combination of body fossils, ichnofossils—such as footprints—and molecular divergence dates to map this history. Molecular data from 30 recent studies suggested the tetrapod crown group originated in the earliest Carboniferous, around 352 million years ago, with amniotes appearing 30 to 35 million years later. These estimates were largely influenced by the fossil record, which appeared to show a gap in the late Devonian. However, this reliance created a circular dependency, as molecular trees were often calibrated using the very fossils they were meant to independently verify.

The discovery of new trackways in Taungurung Country, Victoria, Australia, has disrupted this consensus. These prints, which feature distinct claw impressions, indicate that crown amniotes were present in northeast Gondwana as early as the Tournaisian. Similar findings in Silesia, Poland, show that amniotes appeared in Euramerica earlier than previously thought as well. These findings imply that the crown tetrapod node must be pushed back deep into the Devonian. By recalibrating the timeline, these tracks suggest that the origin of amniotes occurred at least 35 to 40 million years earlier than earlier models proposed, fundamentally changing our understanding of how vertebrates conquered the land.

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