Ultrastenos: The Evolution and Revision of an Australian Mekosuchine

Ultrastenos is an extinct genus of Australian crocodilian from the Late Oligocene, primarily discovered within the Riversleigh World Heritage Area. Although researchers initially hypothesized it was a long-snouted predator similar to a gharial, a 2024 taxonomic revision clarified that it actually possessed a short, flattened snout. This updated study also determined that Ultrastenos willisi is a synonym for the previously named "Baru" huberi, leading to the official scientific name Ultrastenos huberi. Measuring approximately 1.5 to 2 meters in length, this reptile was a small member of the Mekosuchinae subfamily. It likely lived in forest lakes and ponds, coexisting with larger relatives by occupying a different ecological niche. These findings provide significant insights into the evolutionary diversity and environmental adaptations of prehistoric Australian crocodiles.