Enchodus
Enchodus is an extinct genus of aulopiform ray-finned fish related to lancetfish and lizardfish. Species of Enchodus flourished during the Late Cretaceous, where they were a widespread component of marine ecosystems worldwide, and there is some evidence that they may have survived to the Paleocene or Eocene; however, this may just represent reworked Cretaceous material.
Description
Enchodus species were small to medium in size, with E. zinensis reaching long. 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 and sometimes over, is known from common remains coming 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 in length, giving its skull an appearance somewhat reminiscent of modern deep-sea fishes, such as anglerfish and viperfish. Other species, such as E. parvus, were considerably smaller, measuring only some centimetres 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 Mexico, South America, Africa, the Middle East, Europe, India, and Japan. 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.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. The earliest known species is E. zimapanensis from the late Albian or earliest Cenomanian of Mexico. Potentially earlier remains are known from the late Barremian/early Aptian of Brazil, but these specimens are too fragmentary to confidently assign to this genus.Species
Enchodus was a diverse, long-lived genus with many species known throughout its temporal and geographic range. The following valid species are known: E. brevis - Cenomanian of the West Bank, Palestine, potentially Lebanon E. bursauxi - Coniacian of Angola, Late Campanian of Egypt, Maastrichtian to potentially Danian of Morocco E. dentex - Cenomanian of Slovenia E. dirus - Maastrichtian of the United States, potentially Gavdos, GreeceE. elegans - Coniacian of Angola, Maastrichtian of Brazil, Niger, Syria, and Jordan ; Maastrichtian to potentially Danian of Morocco E. faujasi - Coniacian of Angola, Campanian of Israel, Maastrichtian of France, Maastrichtian/potentially Danian of the Netherlands E. ferox - Santonian of Orenburg, Russia; Campanian to Maastrichtian of the United States ; Maastrichtian of Argentina and India E. gladiolus - Cenomanian to Maastrichtian of the United States, Santonian to Campanian of Russia, Maastrichtian of Argentina, potentially Peru E. gracilis - Campanian of Germany E. lewesiensis - Cenomanian to Coniacian of England, Cenomanian/Turonian of Germany and the Czech Republic, potentially Maastrichtian of Germany E. libycus - Cenomanian to Maastrichtian of Brazil, Campanian of Egypt, Maastrichtian to potentially Danian of Morocco E. longidens - Santonian of Lebanon, potentially Paleocene/early Eocene of India E. longipectoralis - Cenomanian to Coniacian of Brazil E. lycodon Kner, 1867 - Cenomanian of Slovenia E. macropterus - Campanian of Germany E. major - Santonian of Lebanon E. marchesettii - Cenomanian of Lebanon E. mecoanalis - Cenomanian of Lebanon E. oliveirai - Cenomanian to Maastrichtian of Brazil E. petrosus - Cenomanian to late Campanian/early Maastrichtian of the United States, Turonian of Canada, Santonian to Campanian of Russia E. shumardi - Cenomanian to Santonian of the United States and Canada E. subaequilateralis - Maastrichtian of Brazil E. tineidae - Campanian of Egypt E. venator - Cenomanian of Morocco, Italy, and Germany E. zinensis Chalifa, 1996 - Campanian/Maastrichtian of EgyptE. zimapanensis - Late Albian/Cenomanian of MexicoMany other dubious species based on insufficient remains have been described throughout its range. Even most of the valid Enchodus species are based on only isolated teeth and bones. The genus Parenchodus, considered to be the sister genus of Enchodus, has been synonymized with this genus based on some studies. However, more recent studies have found it to be a valid genus distinct from Enchodus.