Palloryctidae

Palloryctidae is a family of extinct ray-finned fish that lived during the Late Cretaceous period. Fossils of this family have been found in what is now North America. Members of the Palloryctidae were relatively small, with most species measuring only a few centimeters in length. They are characterized by their elongated bodies, small scales, and a single dorsal fin. The dentition of palloryctids suggests they were likely predators, feeding on small invertebrates or other small fish.

The taxonomic classification of Palloryctidae has been debated, with some researchers placing them within the order Clupeiformes, which includes modern-day herrings and sardines. Others suggest a closer relationship to the Osteoglossomorpha, a group that includes ancient and modern bony-tongued fishes. The limited fossil record makes a definitive placement challenging. The most well-known genus within this family is Palloryctes, from which the family name is derived. Several species have been described, primarily from the Lance Formation in Wyoming, USA. The extinction of the Palloryctidae likely occurred at the end of the Cretaceous period, coinciding with the Cretaceous-Paleogene extinction event that wiped out many other species. Their ecological role in Cretaceous freshwater or brackish environments is not fully understood, but their presence adds to our knowledge of the diversity of fish life before the mass extinction.