''Tadzhikosuchus'' (also spelt ''Tajikosuchus'') 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
neosuchian
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 crocodylomorphs more closely related to ''Crocodylus niloticus' ...
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 ...
from the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
of
Tajikistan
Tajikistan, officially the Republic of Tajikistan, is a landlocked country in Central Asia. Dushanbe is the capital city, capital and most populous city. Tajikistan borders Afghanistan to the Afghanistan–Tajikistan border, south, Uzbekistan to ...
. Three species have been named: 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 ...
''T. macrodentis'', described by Efimov in 1982 from the lower
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 ...
-age
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cret ...
Ialovachsk Formation of Kansai, Tajikistan, in the
Fergana Basin of Tajikistan; ''T. neutralis'' from the same location, by Efimov in 1988; and ''T. kizylkumensis'' from
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), ...
-age rocks of the
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cret ...
Bissekty Formation
The Bissekty Formation (sometimes referred to as Bissekt) is a formation (geology), geologic formation and Lagerstätte which outcrop, crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period (geology), Period. Laid ...
of Dzharakhuduk,
Uzbekistan
, image_flag = Flag of Uzbekistan.svg
, image_coat = Emblem of Uzbekistan.svg
, symbol_type = Emblem of Uzbekistan, Emblem
, national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...
, by Nesov and colleagues in 1989. However, a 2000 review by Glenn Storrs and Mikhail Efimov could not differentiate between the species based on their
type material
In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...
, and recommended grouping the specimens of all three species under ''T. macrodentis''. They also could not determine how ''Tadzhikosuchus'' and the contemporaneous ''
Zhyrasuchus'' were related, or even if they were synonyms, due to the poor fossils available.
The name of ''Tadzhikosuchus'' is derived from the Russian spelling of Tajikistan.
To date, ''Tadzhikosuchus'' is mostly known from partial
dentaries, which were initially considered to have been very similar to ''
Prodiplocynodon
''Prodiplocynodon'' is an extinct genus of basal crocodyloid crocodylian. It is one of the only crocodyloids known from the Cretaceous and existed during the Maastrichtian stage. The only species of ''Prodiplocynodon'' is the type species ''P. ...
'' (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 ...
) by Efimov. However, since dentaries are not known for ''Prodiplocynodon'', this conclusion was considered questionable by Jeremy Martin and Massimo Delfino in 2010. They instead suggested that it may have belonged to the
Paralligatoridae
Paralligatoridae is an extinct family of neosuchian crocodyliforms that existed during the Jurassic and Cretaceous periods. It includes the genera '' Paralligator'', '' Brillanceausuchus'', '' Kansajsuchus'', '' Shamosuchus'', '' Scolomastax'', ...
, which was common in Asia at the time.
References
Neosuchia
Turonian life
Late Cretaceous crocodylomorphs of Asia
Fossils of Uzbekistan
Bissekty Formation
Prehistoric pseudosuchian genera
Fossil taxa described in 1982
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