Eutrichiurides

Eutrichiurides ("true Trichiurus resemblance") is an extinct genus of cutlassfish known from the early Paleocene to the early Oligocene.^[1][2]

Eutrichiurides Temporal range: Early Paleocene to Early Oligocene PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Scombriformes
Family:	Trichiuridae
Genus:	†Eutrichiurides Casier, 1944
Type species
†Trichiurides delheidi Leriche, 1908
Species
See text

Taxonomy

Species within this genus include:^[3]

• †E. africanus Dartevelle & Casier, 1949 - mid-late Paleocene (Selandian to Thanetian) of Angola (Landana Formation)^[4][5]
• †E. delheidi (Leriche, 1908) (type species) - Early Oligocene of Belgium (Boom Clay) (=Trichiurides delheidi Leriche, 1908)^[6]
• †E. orpiensis (Leriche, 1906) - Early Paleocene of Morocco & North Dakota, USA (Cannonball Formation), Late Paleocene of Belgium, Early Eocene of England^[7][8]
• †E. plicidens (Arambourg, 1952) - middle Eocene (early Lutetian to middle Bartonian) of Alabama, USA (Tallahatta, Lisbon and Gosport Sand Formations), potentially Bartonian of Libya^[9]
• †E. goberti Casier, 1944 - Early Eocene of Tunisia (Gafsa-Metlaoui Basin)^[10]
• †E. termieri (Arambourg, 1952) - Late Paleocene/Early Eocene of Morocco (Ouled Abdoun Basin)^[11][12]

E. delheidi is the only member of this genus known from partial skull elements (including a partial jawbone) instead of only isolated teeth. The former species E. winkleri Casier, 1946 from the London Clay^[13] has been moved to its own genus, Macroynis, as an indeterminate trichiuroid, as there is no evidence that it is a member of this genus.^[6]

Fossil teeth of an indeterminate Eutrichiurides have been recovered from the high-latitude Eureka Sound Formation of Nunavut, Canada, suggesting that this genus ranged as far north as the Arctic Circle during the Early Eocene Climatic Optimum.^[14] Indeterminate teeth are also known from the middle Eocene-aged Shark River Formation of New Jersey,^[15] the Early Eocene-aged Khuiala Formation & Cambay Shale of Gujarat & Rajasthan, India,^[16][17] the late Eocene-aged Fayum Depression of Egypt,^[18] and the Early Oligocene of the Paris Basin of France.^[19]

Description

Eutrichiurides species were very similar in form and build to modern cutlassfish, in that they were long and slender, blade-shaped fishes with elongated jaws possessing fangs and needle-shaped teeth.^[20]

See also

• Paleontology portal
• Fish portal

• Prehistoric fish
• List of prehistoric bony fish