Parahesperornithid

Parahesperornithidae is an extinct family of flightless birds that lived during the Late Cretaceous period. These birds are known from fossil remains found primarily in North America. They are classified within the order Hesperornithiformes, which comprises other ancient, toothed, diving birds.

Members of the Parahesperornithidae family were adapted for a marine environment. Like other hesperornithiforms, they were incapable of flight and possessed a body plan suited for diving and swimming. Their legs were positioned far back on their bodies, facilitating efficient propulsion through water. While they had teeth in their jaws, these were likely used for gripping slippery prey rather than for chewing.

The exact relationship between Parahesperornithidae and other hesperornithiform families is still a subject of scientific study. However, they are generally considered to be more primitive or basal members of the group, possibly representing an earlier evolutionary divergence. Their presence in the fossil record contributes to our understanding of the diversity and evolution of early birds during the Mesozoic Era. The extinction of the Parahesperornithidae, along with the rest of the Hesperornithiformes, occurred at the end of the Cretaceous period, likely due to environmental changes and competition.