The Late Triassic (ca. 225 million years ago) was an important period in the evolutionary history of ichthyosaurs, which saw the rise of their advanced ‘fish-shaped’ representatives. However, the evolution of ichthyosaurs in the Late Triassic is incompletely known due their sparse fossil record from this time interval. The new article describes Late Triassic ichthyosaur faunas from the New Siberian Islands in the Russian Far East, including a new species – Auroroborealia incognita. This new ichthyosaur was likely closely related to the ancestors of the „fish-shaped” ichthyosaurs, as demonstrated by its mosaic anatomy, comprising both primitive and advanced features.
Reconstruction: Andrey Atuchin