''Notosuchus'' (; 'southern crocodile') 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 ...
of South American
notosuchia
Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group (see below); if Sebecosu ...
n
crocodylomorph
Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction.
During Mesozoic and early Cenozoic times, cro ...
. It was terrestrial, living approximately 85 million years ago in the
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 mya. The ...
stage of the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger 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 ''creta'', the ...
.
Description
''Notosuchus'' was relatively small, reaching in length and a weight of .
Remains have been found in the
Bajo de la Carpa Formation
The Bajo de la Carpa Formation is a geologic formation of the Neuquén Basin that crops out in northern Patagonia, in the provinces of Río Negro and Neuquén, Argentina. It is the oldest of two formations belonging to the Río Colorado Subgr ...
in
Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...
,
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. First named in 1896, ''Notosuchus'' was the first known notosuchian.
The type species is ''N. terrestris''. A second species, ''N. lepidus'', was named in 1957.
A paper published in 2008 by Fiorelli and Calvo described new remains of 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 ...
''N. terrestris''.
In it, the authors suggested that the skull would have supported a short trunk, or "hog's snout" as well as fleshy upper and lower lips. The anteriorly directed nares and the absence of a bony
nasal septum
The nasal septum () separates the left and right airways of the Human nose, nasal cavity, dividing the two nostrils.
It is Depression (kinesiology), depressed by the depressor septi nasi muscle.
Structure
The fleshy external end of the nasal ...
(which presumably indicates cartilaginous tissue serving its place) provide evidence for a trunk-like snout, while striations on the surface of the
nasal bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose.
Eac ...
s and the lower jaw most likely acted as attachment points for the
nasolabial muscles and the depressor muscle, respectively.
[Fiorelli, L. E. (2005). "Nuevos restos de ''Notosuchus
terrestris'' Woodward, 1896 (Crocodyliformes: Mesoeucrocodylia) del Cretácico Superior (Santoniano) de la Provincia de Neuquén, Patagonia, Argentina". 79p. Tesis (Grado) Universidad Nacional de Córdoba, Córdoba.] Additionally, the authors suggested that a lateral rim on the
dentary
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
as well as numerous aligned
neurovascular foramina are evidence of soft
cheek
The cheeks ( la, buccae) constitute the area of the face below the eyes and between the nose and the left or right ear. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside ...
-like muscular tissue. The function of the trunk was likely used for searching for food by sniffing the ground in a manner similar to extant
suids and
peccaries
A peccary (also javelina or skunk pig) is a medium-sized, pig-like hoofed mammal of the family Tayassuidae (New World pigs). They are found throughout Central and South America, Trinidad in the Caribbean, and in the southwestern area of North A ...
, while the cheeks would aid in
mastication
Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...
by preventing food loss.
[ A re-description of the skull material has since lent evidence toward minimal soft-tissue enhancement to the snout of ''Notosuchus''.]
References
Late Cretaceous crocodylomorphs of South America
Ziphosuchians
Terrestrial crocodylomorphs
Bajo de la Carpa Formation
Fossil taxa described in 1896
Taxa named by Arthur Smith Woodward
Prehistoric pseudosuchian genera
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