Edestus

Edestus is an extinct genus of eugeneodontid holocephalian fish known from the Late Carboniferous (Pennsylvanian) of the United Kingdom, Russia, and the United States. Most remains consist of isolated curved blades or "whorls" that are studded with teeth, that in life were situated within the midline of the upper and lower jaws. Edestus is a Greek name derived from the word edeste (to devour), in reference to the aberrant quality and size of the species' teeth. The largest species, E. heinrichi, has been conservatively estimated to reach greater than 6.7 m (22 ft) in length, around the size of the largest known great white shark, possibly making it the largest marine predator known to have ever existed up to that point. Like its other relatives, such as Helicoprion, and unlike modern sharks, the species of Edestus grew teeth in curved blades or "whorls". In Edestus ' case, only a single row of teeth occurred in the midline of each jaw, leading Edestus to sometimes be described as the "scissor tooth shark". The degree of curvature in the teeth brackets, along with size, are distinct in each species.

Edestus is an extinct genus of eugeneodontid holocephalian fish known from the Late Carboniferous (Pennsylvanian) of the United Kingdom, Russia, and the United States. Most remains consist of isolated curved blades or "whorls" that are studded with teeth, that in life were situated within the midline of the upper and lower jaws. Edestus is a Greek name derived from the word edeste (to devour), in reference to the aberrant quality and size of the species' teeth. The largest species, E. heinrichi, has been conservatively estimated to reach greater than 6.7 m (22 ft) in length, around the size of the largest known great white shark, possibly making it the largest marine predator known to have ever existed up to that point. Like its other relatives, such as Helicoprion, and unlike modern sharks, the species of Edestus grew teeth in curved blades or "whorls". In Edestus ' case, only a single row of teeth occurred in the midline of each jaw, leading Edestus to sometimes be described as the "scissor tooth shark". The degree of curvature in the teeth brackets, along with size, are distinct in each species.

Classification and species

13 species of Edestus have been named, but in a 2019 morphometric analysis only 4 were considered valid, which span a six million year interval in the Late Carboniferous (313-307 million years ago). Species of Edestus are divided into two groups, those which have asymmetrical crowns that slant forwards, and those with symmetrical ones. The earliest known species are from the late Bashkirian of the United Kingdom, with the first appearances in Russia and the United States during the Moscovian, corresponding to a rise in sea level.

References

Photographs and a 3D scan of the type specimen of Edestus triserratus, provided by the GB3D Type Fossils project

Text derived from https://en.wikipedia.org/w/index.php?oldid=1371899554 under CC BY-SA 4.0; modifications have been made.