An artist’s impression of the lizard-like creature making tracks
Marcin Ambrozik
Evidence of the earliest known reptile-like animal, an ancestor of many four-limbed creatures including birds, reptiles, and mammals, has been discovered in Victoria, Australia. This finding could potentially redefine the timeline of when these animals transitioned from water to land, marking a significant evolutionary milestone in the history of life on Earth.
Unearthed in 2021 by amateur fossil enthusiasts along the banks of the Broken River near Mansfield, Victoria, a sandstone slab measuring approximately 40 centimeters across revealed three sets of tracks believed to have been left by the same tetrapod species. Two of the track sets exhibit five digits with curved claws, indicating characteristics of an amniote.
Upon analysis by John Long and his team at Flinders University in Adelaide, the fossil was dated to around 356 million years ago, significantly earlier than previously known clawed fossils found in Nova Scotia, Canada. Long affirms that the distinct features observed in the tracks confirm the presence of an amniote, eliminating the possibility of the creature being an amphibian.
According to Long, the presence of well-developed claws suggests that the fossil tracks represent the earliest evidence of a reptile inhabiting terrestrial environments. This pivotal development allowed amniotes to reproduce on land without the need to return to water, enabling them to colonize various continents.
The fossil tracks show front foot prints (in yellow) and rear footprints (blue)
Grzegorz Niedzwiedzki
Despite the compelling evidence presented by Long and his team, trackway experts Steven Salisbury and Anthony Romilio from the University of Queensland express reservations regarding the interpretation of the fossils. While acknowledging the significance of the find, Salisbury and Romilio question whether the observed features truly represent claws or simply pointed digits.
In response to skepticism, Long defends the findings, emphasizing the presence of distinct claw marks in the footprints. He also addresses concerns about the timing of raindrop impressions on the slab, asserting that the tracks were made on land and not submerged underwater.
Overall, the discovery of these ancient reptile tracks in Victoria sheds new light on the early evolution of terrestrial vertebrates and underscores the importance of continued research in unraveling the mysteries of prehistoric life.
Topics:
