''Enaliosuchus'' is a dubious

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

marine

crocodyliform Crocodyliformes is a clade of Crurotarsi, crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the ...

within the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Metriorhynchidae Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period ( Bajocian to early Aptian) of Europe, North America and South America. The name Metriorhynchid ...

that lived during the

Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 137.05 ± 0.2 Ma and 132.6 ± 0.2 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretac ...

stage of the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

. It is known from fossil remains found in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

and

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

and it was first described in 1883. Only the

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 ...

is known, which is ''E. macrospondylus''.

Etymology

The name ''Enaliosuchus'' means "Marine crocodile", and is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''Enalios''- ("marine") and -''suchos'' ("crocodile").

Discovery and naming

The holotype, specimen MB.R.1943.1–16, consists of an atlas-axis complex, three post-axial cervical vertebrae, several dorsal vertebrae, a caudal vertebra, an incomplete femur and a fragmentary sacral rib, and it was discovered in the

Stadthagen Formation The Stadthagen Formation is a geological formation located in Hanover, Germany, dating to the Early Cretaceous (Valanginian). The formation contains fossils of reptiles and fish, suggesting that the formation was once a shallow marine setting.''P ...

. The species ''Enaliosuchus macrospondylus'' was then named for this specimen by Koken (1883). Isolated teeth were subsequently found across Germany and have been assigned to ''Enaliosuchus'', and a partial specimen (specimen RNGD 990201) discovered in the Campylotoxus Zone of

was assigned to ''Enaliosuchus macrospondylus'' by Hua et al. (2000).

Description

''Enaliosuchus'' was a

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

that spent much, if not all, its life out at sea.Hua, S., Vignaud, P., Atrops, F. & Clément, A. (2000). ''Enaliosuchus macrospondylus'' Koken, 1883 (Crocodylia, Metriorhynchidae) du Valanginien de Barret-le-Bas (Hautes Alpes, France): un cas unique de remontée des narines externes parmi les crocodiliens. ''Geobios'' 33: 467-474. No ''Enaliosuchus'' eggs or nest have been discovered, so little is known of the reptile's lifecycle, unlike other large marine reptiles of the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

, such as

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

s or

ichthyosaurs Ichthyosauria is an taxonomy (biology), order of large extinction, extinct marine reptiles sometimes referred to as "ichthyosaurs", although the term is also used for wider clades in which the order resides. Ichthyosaurians thrived during much of ...

which are known to give birth to live young out at sea. Where ''Enaliosuchus'' mated, whether on land or at sea, is currently unknown.

Species

The species within ''Enaliosuchus'' include : * ''E. macrospondylus'':

from

and

of the Early Cretaceous (

). Recent

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses found the genus ''Enaliosuchus'' to be

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

, but also to be nested within the genus ''

Geosaurus ''Geosaurus'' is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous. ''Geosaurus'' was a carnivore that spent much, if not all, its life out at sea. No ''Geosa ...

'' or ''

Cricosaurus ''Cricosaurus'' is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian (Late Jurassic) of Germany ...

''.Young M. T. (2007). The evolution and interrelationships of Metriorhynchidae (Crocodyliformes, Thalattosuchia). ''Journal of Vertebrate Paleontology'' 27 (3): 170A.Wilkinson L. E, Young M. T, Benton M. J. (2008). A new metriorhynchid crocodilian (Mesoeucrocodylia: Thalattosuchia) from the Kimmeridgian (Upper Jurassic) of Wiltshire, UK. ''Palaeontology'' 51 (6): 1307-1333. Sachs ''et al.'' (2020) hypothesised that the two species within the genus ''Enaliosuchus'' were not monophyletic. They hypothesised that ''E. schroederi'' belonged to a new, undescribed, genus. In 2024, ''Enaliosuchus schroederi'', from

,"Kuhn, O. (1936). ''Crocodilia. Fossilium Catalogus I: Animalia 75.'' Gracenhage: Junk, 114pp. which was previously believed to likely be a junior synonym of ''E. macrospondylus'', was moved to the new genus ''

Enalioetes ''Enalioetes'' is an extinct genus of metriorhynchid thalattosuchian from the Early Cretaceous Stadthagen Formation of Germany. The type species is ''E. schroederi''. Prior to its description in 2024, it was known under the informal names '' E ...

'' in 2024.

References

{{Taxonbar, from= Q9253811 Prehistoric pseudosuchian genera Prehistoric marine crocodylomorphs Early Cretaceous extinctions Early Cretaceous crocodylomorphs of Europe Fossil taxa described in 1883