''Protoalligator'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

alligatoroid Alligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members mor ...

crocodilian Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living ...

found in the

Anhui Anhui , (; formerly romanized as Anhwei) is a landlocked province of the People's Republic of China, part of the East China region. Its provincial capital and largest city is Hefei. The province is located across the basins of the Yangtze River ...

province of China and lived during the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

Taxonomy

''P. huiningensis'', was originally named ''Eoalligator huiningensis'', which therefore remains the

type species In 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 species that contains the biological type specimen ...

of the genus.Young CC. 1982. A Cenozoic crocodile from Huaining, Anhui. Selected Works of Yang Zhongjian. China: Academia Sinica. 47-48 But then a 2016 study of Chinese alligators by Wang ''et al.'' found the

'' Eoalligator chunyii'' to be a junior

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of '' Asiatosuchus nanlingensis'' and a basal member of

Crocodylidae Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant mem ...

. However, a subsequent study by Wu ''et al.'' disagreed with the synonymy of ''"Asiatosuchus" nanlingensis'' and ''Eoalligator chunyii'', finding them to be distinct based on first-hand studies of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

s and

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis, although they agreed in classifying ''E. chunyii'' as a

crocodyloid Crocodyloidea is one of three superfamilies of crocodilians, the other two being Alligatoroidea and Gavialoidea, and it includes the crocodiles. Crocodyloidea may also include the extinct Mekosuchinae, native to Australasia from the Eocene to th ...

. In 2016, Wang ''et al.'' also found ''Eoalligator huiningensis'' to be an

distinct from ''E. chunyii'', and thus moved ''Eoalligator huiningensis'' to the new genus ''Protoalligator''. A 2019 study by Massonne ''et al.'' included additional taxa from

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

and found ''

Eoalligator ''Eoalligator'' is an extinct genus of alligatoroid crocodilian from Paleocene deposits in China. Systematics ''Eoalligator'' was originally classified as an extinct relative of alligators. The holotype of ''E. chunyii'', IVPP V2716, is a partia ...

'' and ''Protoalligator'' to be related and as basal members of

Alligatoroidea Alligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members more c ...

, as shown in the

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below:

References

Crocodilians Paleocene reptiles of Asia Paleocene crocodylomorphs Fossil taxa described in 2016 Prehistoric pseudosuchian genera {{paleo-archosaur-stub