Enchodus

Enchodus (from ἔγχος enchos, 'spear' and ὀδούς odoús 'tooth') is an extinct genus of aulopiform ray-finned fish related to lancetfish and lizardfish. Species of Enchodus flourished during the Late Cretaceous, and there is some evidence that they may have survived to the Paleocene or Eocene; however, this may just represent reworked Cretaceous material.

Taxonomy
Species of Enchodus are generally classified into two different clades, the North American and the Mediterranean. It has been proposed that this distinction is the result of several isolated events between the two populations over the Late Cretaceous.

Description
Enchodus species were small to medium in size, large species (E. zinensis) reached 172.2 cm. One of the genus' most notable attributes are the large "fangs" at the front of the upper and lower jaws and on the palatine bones, leading to its misleading nickname among fossil hunters and paleoichthyologists, "the saber-toothed herring". These fangs, along with a long sleek body and large eyes, suggest Enchodus was a predatory species.

E. petrosus, with standard length around 76.7 cm and sometimes over 1 m, remains of which are common from the Niobrara Chalk, the Mooreville Chalk Formation, the Pierre Shale, and other geological formations deposited within the Western Interior Seaway and the Mississippi Embayment. Large individuals of this species had fangs measuring over 6 cm in length, giving its skull an appearance somewhat reminiscent of modern deep-sea fishes, such as anglerfish and viperfish. Other species were considerably smaller, some like E. parvus were only some centimeters (a few inches) long.

Despite being a formidable predator, remains of Enchodus are commonly found among the stomach contents of larger predators, including sharks, other bony fish, mosasaurs, plesiosaurs and seabirds such as Baptornis advenus.

Distribution
Enchodus fossils have been found all over the world. In North America, Enchodus remains have been recovered from most US states with fossiliferous Late Cretaceous rocks, including Kansas, Nebraska, Colorado, Alabama, Mississippi, Georgia, Tennessee, Wyoming, Texas, California, North Carolina, and New Jersey. Fossils also have been found in the Aguja and El Doctor Formations of Mexico and the Ashville, Vermillion River and Dinosaur Park Formations, and Brown Bed Member of Canada. The taxon is also known from coeval strata in Africa, the Middle East, Europe, southwest Asia and the Tiupampan Santa Lucía Formation and Maastrichtian El Molino Formation of Bolivia and the Paraíba, Pernambuco and Sergipe states of Brazil. Potentially the latest Enchodus remains are known from the earliest Eocene of Barmer, India. However, it has also been suggested that all post-Cretaceous Enchodus records are just reworked material.