Kalmashyapus

Kalmashyapus is a genus of extinct birds belonging to the order Hesperornithiformes. These ancient birds are known primarily from fossilized remains found in the Late Cretaceous period, dating back approximately 70 to 80 million years ago. The most notable fossils have been discovered in North America, particularly in the Western Interior Seaway region.

These birds were adapted for a marine lifestyle. Evidence suggests they were diving birds, likely preying on fish and other small marine organisms. Unlike modern birds, Kalmashyapus possessed several reptilian features, including teeth set in sockets rather than fused to the jawbone, and a pelvis that was not fused. Their wings were vestigial and likely not capable of flight, indicating they were entirely terrestrial for nesting and vulnerable on land.

The skeletal structure of Kalmashyapus reveals a powerful breastbone and strong leg muscles, consistent with their diving capabilities. Their overall appearance is thought to have been somewhat primitive, with a long body and a relatively short tail. The classification within Hesperornithiformes places them alongside other flightless, diving birds that shared similar adaptations to the Cretaceous marine environments. The extinction of Kalmashyapus, like that of the Hesperornithiformes, is generally attributed to the K-Pg extinction event that wiped out the non-avian dinosaurs.