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''Smilosuchus'' (meaning "chisel crocodile") is an extinct
The type species was first described in 1995 as a replacement generic name for ''Leptosuchus gregorii''. Because of the large rostral crest it possessed, it was considered to be distinct enough from other species of '' Leptosuchus'' (all of which had smaller and more restricted crests) to be within its own genus. Some studies seem to suggest that ''Smilosuchus'' is congeneric with ''Leptosuchus'', as the enlarged crest could have been independently developed in ''Leptosuchus''. However, newer studies support the idea that ''Smilosuchus'' is distinct from the type species of ''Leptosuchus'', ''Leptosuchus crosbiensis''. Phylogenetic analyses suggest that ''Smilosuchus'' is more closely related to mystriosuchins than to ''Leptosuchus'' species.
Like all phytosaurs, ''Smilosuchus'' had the nostrils close to the top of its head. The
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of leptosuchomorph parasuchid
Parasuchidae is a clade of phytosaurs more derived than ''Diandongosuchus'', a basal phytosaur. It encompasses nearly all phytosaurs, include early ''Parasuchus''-grade forms as well as a more restricted clade of more specialized phytosaurs. This ...
from the Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...
of North America.
History
The type species was first described in 1995 as a replacement generic name for ''Leptosuchus gregorii''. Because of the large rostral crest it possessed, it was considered to be distinct enough from other species of '' Leptosuchus'' (all of which had smaller and more restricted crests) to be within its own genus. Some studies seem to suggest that ''Smilosuchus'' is congeneric with ''Leptosuchus'', as the enlarged crest could have been independently developed in ''Leptosuchus''. However, newer studies support the idea that ''Smilosuchus'' is distinct from the type species of ''Leptosuchus'', ''Leptosuchus crosbiensis''. Phylogenetic analyses suggest that ''Smilosuchus'' is more closely related to mystriosuchins than to ''Leptosuchus'' species.
Description
Like all phytosaurs, ''Smilosuchus'' had the nostrils close to the top of its head. The rostra
The rostra ( it, Rostri, links=no) was a large platform built in the city of Rome that stood during the Roman Republic, republican and Roman Empire, imperial periods. Speakers would stand on the rostra and face the north side of the comitium tow ...
teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, te ...
are heterodont
In anatomy, a heterodont (from Greek, meaning 'different teeth') is an animal which possesses more than a single tooth morphology.
In vertebrates, heterodont pertains to animals where teeth are differentiated into different forms. For example, ...
, with large tusks at the anterior of the mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on t ...
for impaling prey
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
and more blade-like teeth for slicing flesh closer to the back of the mouth. The tusks are mounted on a bulge at the tip of the snout present in nearly all phytosaurs. Its squamosal processes are short and deep, indicating a powerful bite. This coupled with its large size (it is one of the largest known phytosaurs) suggests that it hunted large prey such as '' Placerias.''
Phylogeny
Below is acladogram
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 ...
from Stocker (2012):
References
Phytosaurs Prehistoric reptile genera Late Triassic reptiles of North America Fossil taxa described in 1995 {{triassic-reptile-stub