''Wannchampsus'' (" Wann Langston, Jr.'s crocodile") is an

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 ...

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 ...

of paralligatorid

neosuchia Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Croc ...

n, close to but not a true

crocodilia Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchia ...

n. It is known from fossils discovered in

Lower Cretaceous Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also * Nizhny {{Disambiguation ...

rocks in north-central

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, United States.

Description and classification

''Wannchampsus'' is based on SMU 76604, a partial skull and lower jaw. This fossil is attached by matrix to another partial skull of the same genus and species, SMU 76605. A handful of other fossils were found associated, mostly representing forelimbs and

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e. These fossils were found in rocks of the late

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

-age Lower Cretaceous Twin Mountains Formation, southwest of Stephenville, in

Comanche County, Texas Comanche County is a county located on the Edwards Plateau in Central Texas. As of the 2020 census, its population was 13,594. The county seat is Comanche. The county was founded in 1856 and is named for the Comanche Native American tribe. H ...

; the site is otherwise known as the Proctor Lake dinosaur locality. ''Wannchampsus'' was described in

2014 The year 2014 was marked by the surge of the Western African Ebola epidemic, West African Ebola epidemic, which began in 2013, becoming the List of Ebola outbreaks, most widespread outbreak of the Ebola, Ebola virus in human history, resul ...

by Thomas Adams. 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 ''W. kirpachi'', in honor of Wesley Kirpach, "who was instrumental in the discovery and excavations of the type specimen". Wkirpachi1

The skulls are described as "low and broad", and are small; SMU 76604 is estimated at long, and SMU 76605 is estimated at long. The lower jaw lacks external mandibular fenestrae, and the third tooth of the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

(main tooth-bearing bone of the upper jaw) and the fourth tooth of the

dentary In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone ...

(tooth-bearing bone of the lower jaw) are enlarged. The teeth become broader and less conical going back toward the jaw joint, and the teeth at the

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

end of the lower jaw project forward (the anterior end of the upper jaw, composed of the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

s, is not known). Features of the skull and vertebrae indicate that the individuals are subadults. Adams performed a

phylogenetic analysis 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 data ...

and found ''Wannchampsus kirpachi'' to be a derived paralligatorid, closely related to the " Glen Rose form", which he regarded as belonging to the genus ''Wannchampsus''.

References

{{Taxonbar, from=Q18182647 Paralligatoridae Early Cretaceous crocodylomorphs of North America Early Cretaceous reptiles of North America Fossil taxa described in 2014 Paleontology in Texas Prehistoric pseudosuchian genera