Stomatosuchidae
Encyclopedia
Stomatosuchidae is an extinct family
of neosuchia
n crocodylomorphs. It is currently defined as the most inclusive clade
containing Stomatosuchus inermis but not Notosuchus terrestris
, Simosuchus clarki
, Araripesuchus gomesii
, Baurusuchus pachecoi
, Peirosaurus torminni
, or Crocodylus niloticus. Two genera are currently known to belong to Stomatosuchidae: Stomatosuchus, the type genus
, and Laganosuchus
. Fossils have been found from Egypt
, Morocco
, and Niger
. Both lived during the Cenomanian
stage of the Late Cretaceous
. The skulls of stomatosuchids are said to be platyrostral because they have unusually flattened, elongate, duck-shaped craniums with U-shaped jaws. This platyrostral condition is similar to what is seen in the "nettosuchid" Mourasuchus
, which is not closely related to stomatosuchids as it is a more derived alligatoroid that existed during the Miocene
.
Unlike Mourasuchus, stomatosuchids have jaws that are less strongly bowed. Additionally, the glenoid
is rounded rather than cupped at the posterior end of the jaw, and the retroarticular process is straight rather than dorsally curving like in Mourasuchus and other extant crocodylians.
The only existing specimens of stomatosuchids belong to the recently described genus Laganosuchus, which is known from two species, L. thaumastos and L. maghrebensis from the Echkar Formation in Niger and the Kem Kem Beds
in Morocco, respectively. The genus Stomatosuchus is known only from a holotype skull collected from the Bahariya Formation
in Egypt, which was destroyed in World War II
with the bombing of the Munich Museum. Because Stomatosuchus is known only from brief accounts by Ernst Stromer
and Franz Nopcsa
(1926) and no additional material has ever been found, the genus remains enigmatic.
The genus Aegyptosuchus
was once considered to be a member of Stomatosuchidae, but it is now placed within its own family, Aegyptosuchidae.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of neosuchia
Neosuchia
Neosuchia is an unranked 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 than to Notosuchus terrestris...
n crocodylomorphs. It is currently defined as the most inclusive clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
containing Stomatosuchus inermis but not Notosuchus terrestris
Notosuchus
Notosuchus is an extinct genus of South American notosuchian crocodylomorph. It was terrestrial, living approximately 85 million years ago in the Coniacian or Santonian stages of the Late Cretaceous. Remains have been found in the Bajo de la Carpa Formation in Patagonia, Argentina. First named in...
, Simosuchus clarki
Simosuchus
Simosuchus is an extinct genus of notosuchian crocodylomorphs from the Late Cretaceous of Madagascar. It is named for its unusually short skull. Fully grown individuals were about in length. The type species is S. clarki, found from the Maevarano Formation in Mahajanga Province.The teeth of S...
, Araripesuchus gomesii
Araripesuchus
Araripesuchus is a genus of extinct crocodyliform whose species existed during the Cretaceous period of the late Mesozoic era some 125 to 65 million years ago. They are generally considered to be notosuchians , characterized by their varied teeth types and distinct skull elements...
, Baurusuchus pachecoi
Baurusuchus
Baurusuchus is an extinct genus of baurusuchid mesoeucrocodylian from the Late Cretaceous of Brazil. It was a terrestrial predator and scavenger, about 3.5 to 4 meters long. Baurusuchus lived during the Turonian to Santonian stages of the Late Cretaceous Period, in Adamantina Formation, Brazil...
, Peirosaurus torminni
Peirosaurus
Peirosaurus is an extinct genus of peirosaurid crocodylomorph. It is the type genus of the family Peirosauridae. Fossils of the type species P. tormini, first described in 1955, have been found from the Marília Formation in Uberaba, Brazil and date back to the late Maastrichtian stage of the Late...
, or Crocodylus niloticus. Two genera are currently known to belong to Stomatosuchidae: Stomatosuchus, the type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
, and Laganosuchus
Laganosuchus
Laganosuchus is an extinct genus of stomatosuchid crocodyliform. Fossils have been found from Niger and Morocco and date back to the Upper Cretaceous. The name means "pancake crocodile" from the Greek laganon and souchos in reference to the shallow depth of the skull, which is characteristic of...
. Fossils have been found from Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, and Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
. Both lived during the Cenomanian
Cenomanian
The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
stage of the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
. The skulls of stomatosuchids are said to be platyrostral because they have unusually flattened, elongate, duck-shaped craniums with U-shaped jaws. This platyrostral condition is similar to what is seen in the "nettosuchid" Mourasuchus
Mourasuchus
Mourasuchus is an extinct genus of giant crocodilian from the Miocene of South America. It was similar in length and weight to Rhamphosuchus...
, which is not closely related to stomatosuchids as it is a more derived alligatoroid that existed during the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
.
Unlike Mourasuchus, stomatosuchids have jaws that are less strongly bowed. Additionally, the glenoid
Mandibular fossa
The mandibular fossa is the depression in the temporal bone that articulates with the mandibular condyle. In the temporal bone, the mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is...
is rounded rather than cupped at the posterior end of the jaw, and the retroarticular process is straight rather than dorsally curving like in Mourasuchus and other extant crocodylians.
The only existing specimens of stomatosuchids belong to the recently described genus Laganosuchus, which is known from two species, L. thaumastos and L. maghrebensis from the Echkar Formation in Niger and the Kem Kem Beds
Kem Kem Beds
The Kem Kem Beds is a geological formation in Morocco and Algeria whose strata date back to the Late Cretaceous...
in Morocco, respectively. The genus Stomatosuchus is known only from a holotype skull collected from the Bahariya Formation
Bahariya Formation
The Bahariya Formation is a fossil bearing geologic formation dating back to the Cenomanian, geographically located in Marsa Matruh, central Egypt.-Lepidosaurs:-Sauropods:Indeterminate sauropod remains.-Theropods:...
in Egypt, which was destroyed in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
with the bombing of the Munich Museum. Because Stomatosuchus is known only from brief accounts by Ernst Stromer
Ernst Stromer
Ernst Freiherr Stromer von Reichenbach was a German paleontologist.He described the following Cretaceous dinosaurs from Egypt: Aegyptosaurus, Bahariasaurus, Carcharodontosaurus, and the largest known theropod, Spinosaurus aegyptiacus...
and Franz Nopcsa
Franz Nopcsa von Felso-Szilvás
Baron Franz Nopcsa von Felső-Szilvás was a Hungarian-born aristocrat, adventurer, scholar, and paleontologist...
(1926) and no additional material has ever been found, the genus remains enigmatic.
The genus Aegyptosuchus
Aegyptosuchus
Aegyptosuchus is an extinct eusuchian genus of the family Aegyptosuchidae. This taxon was coined by Kuhn as a monotypic family-level taxon redundant with the Cretaceous genus Aegyptosuchus. Carroll classified the genus in the family Stomatosuchidae. Only one species is descript, Aegyptosuchus...
was once considered to be a member of Stomatosuchidae, but it is now placed within its own family, Aegyptosuchidae.
External links
- Stomatosuchidae in the Paleobiology DatabasePaleobiology Database' is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.-History:The Paleobiology Database was founded in 2000. It has been funded by the National Science Foundation and the Australian Research Council...