''Apateodus'' (meaning "confusing tooth") is a genus of prehistoric marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

which was described by Woodward in 1901. It was a relative of modern

lizardfish The Synodontidae or lizardfishes(or typical lizardfish to distinguish them from the Bathysauridae and Pseudotrichonotidae) are benthic (bottom-dwelling) marine and estuarine bony fishes that belong to the aulopiform fish order, a diverse grou ...

and lancetfish in the order

Aulopiformes Aulopiformes is a diverse order (biology), order of Marine (ocean), marine ray-finned fish consisting of some 15 Extant taxon, extant and several prehistoric family (biology), families with about 45 genera and over 230 species. The common names ...

, and one of a number of prominent nektonic aulopiforms of

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

marine ecosystems. The genus spans from the

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

to the late

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

, and appears to have been distributed worldwide; specimens have been found in Russia, India, the United States (Colorado, South Dakota, Iowa, Kansas), Canada, the United Kingdom and the Netherlands.

Taxonomy

''Apateodus'' has generally been placed in the suborder

Enchodontoidei The Enchodontoidei are an extinct superorder of aulopiform fish known from the Early Cretaceous to the Eocene. They were among the dominant predatory marine fish groups in the Late Cretaceous, achieving a worldwide distribution. They were an ext ...

alongside most other Cretaceous nektonic aulopiforms, although its affinities have long been uncertain. However, since the 2000s, it has generally been placed in the family Ichthyotringidae. However, some authors have still placed it as an indeterminate enchodontoid, ichthyotringoid, alepisauroid, or even elsewhere in the Aulopiformes as the sister to the

barracudina Barracudinas are any member of the marine mesopelagic fish family Paralepididae: 50 or so extant species are found almost worldwide in deep waters. Several genera, including '' Holosteus'' and '' Drimys'', are known only from fossils dating b ...

s, the latter two of which have been contradicted by anatomical studies. The following species are known: * †?''A. assisi'' Schwarzans, Huddlestone & Takeuchi, 2018 -

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

, USA (

Eutaw Formation The Eutaw Formation is a geological Formation (geology), formation in North America, within the United States, U.S. states of Alabama, Georgia (U.S. state), Georgia, and Mississippi. The strata date from the late Coniacian to the early Santonian S ...

) nowiki/>otolith">otolith.html" ;"title="nowiki/>otolith">nowiki/>otolith* †''A. busseni'' Franz & Shimada, 2009 - Coniacian of Kansas, USA (Smoky Hill Chalk) * †''A. corneti'' (Forir, 1887) -

of the Netherlands (

Maastricht Formation The Maastricht Formation (Dutch language, Dutch: ''Formatie van Maastricht''; abbreviation: MMa), named after the city of Maastricht in the Netherlands, is a geological Formation (geology), formation in the Netherlands and Belgium whose strata dat ...

) * †''A. crenellatus'' Schwarzans & Stringer, 2020 - Maastrichtian of

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

, USA tolith( Owl Creek Formation) * †''A. glyphodus'' (Blake, 1863) (

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

) -

of the United Kingdom ( Folkestone Formation) * †''A. lanceolatus'' Woodward, 1901 -

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

of the United Kingdom ( English Chalk) * †''A. striatus'' Woodward, 1901 - Cenomanian of the United Kingdom (English Chalk), Cenomanian-Turonian of Germany (

Hesseltal Formation The Hesseltal Formation or Blackcoloured Formation is a Late Cretaceous (late Cenomanian to early Turonian) geological formation from northern Germany. It consists of lithified marls and limestone, with a unique series of black shales deposited ...

), Maastrichtian of India (

Intertrappean Beds The Intertrappean Beds are a Late Cretaceous and early Paleogene geologic unit in India. These beds are found as interbeds between Deccan Traps layers, including the slightly older Lameta Formation. They consist a number of different subgroups ...

) Indeterminate remains are known from the

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

of Canada ( Kaskapau Formation of

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

), the Albian of Russia (

Belgorod Belgorod (, ) is a city that serves as the administrative center of Belgorod Oblast, Russia, located on the Seversky Donets River, approximately north of the border with Ukraine. It has a population of It was founded in 1596 as a defensiv ...

), and the Cenomanian to Santonian of the United States ( Greenhorn Limestone of Colorado & Iowa, Carlile Shale of Kansas, and the

Niobrara Formation The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is com ...

of South Dakota). A potential undescribed genus closely allied to ''Apateodus'' was identified in 2020 from fossils from Kansas.

Description

Known by well preserved skull remains, ''Apateodus'' is estimated to be around 1 meter (3.3 ft) in length, and would have been an effective

mesopredator A mesopredator is a predator that occupies a mid-ranking trophic level in a food web. There is no standard definition of a mesopredator, but mesopredators are usually medium-sized carnivorous or omnivorous animals, such as raccoons, foxes, or ...

References

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species or languages). It is one of the mo ...

Prehistoric ray-finned fish genera Fossils of India Fossils of Russia Fossils of the United States Fossils of Canada Fossils of England Fossils of Germany Fossils of the Netherlands Cretaceous bony fish Late Cretaceous fish of North America Cretaceous fish of Europe Late Cretaceous fish of Asia Albian genus first appearances Cenomanian genera Coniacian genera Maastrichtian genus extinctions Fossil taxa described in 1901 Taxa named by Arthur Smith Woodward {{Aulopiformes-stub