Listrognathosuchus

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Listrognathosuchus
Temporal range: Middle Paleocene
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Superfamily: Alligatoroidea
Genus: Listrognathosuchus
Brochu, 1997
Species

Listrognathosuchus is an extinct genus of alligatoroid crocodilian. Fossils date back to the middle Paleocene epoch. In 1997, the generic name replaced that of Leidyosuchus for the species L. multidentatus (now the type species of Listrognathosuchus). [1] "L." multidentalis was first described by Charles Mook in 1930 on the basis of the holotype AMNH 5179, consisting of a partial vertebral column, mandible, partial left ilium, and left tibia, found from a locality in Torrejon Arroyo, New Mexico (then referred to as the Torrejon beds, and now thought to be part of the Nacimiento Formation). [2]

Phylogenetics

The fragmentary nature of the material referable to Listrognathosuchus have made it hard to classify within Crocodylia, but it is now thought to be a relatively basal alligatoroid. Listrognathosuchus is closely related to Borealosuchus , a more basal eusuchian that is not an alligatoroid, but rather a close relative of a monophyletic group of which the superfamilies Alligatoroidea and Crocodyloidea comprise. In fact, Borealosuchus was first used as a replacement name for four species of Leidyosuchus, the same genus that Listrognathosuchus multidentatus once belonged to. Prior to the reassessment of Leidyosuchus in 1997, many relationships for the genus within Crocodilia have been considered. It was suggested to be a possible member of Diplocynodontinae [3] [4] or a relative of later crocodylids, [5] [6] [7] [8] and even as a member of its own subfamily of broad snouted early eusuchians, Leidysuchinae. [9] [10] [11] However, with the naming of Listrognathosuchus and Borealosuchus, most species previously assigned to Leidyosuchus are now believed to have had little relation to any of the mentioned crocodilians.

Related Research Articles

<i>Deinosuchus</i> Genus of a giant crocodylian

Deinosuchus is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos (δεινός), "terrible", and soukhos (σοῦχος), "crocodile". The first remains were discovered in North Carolina in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.

<i>Goniopholis</i> Extinct genus of reptiles

Goniopholis is an extinct genus of goniopholidid crocodyliform that lived in Europe and Africa during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles. It ranged from 2–4 metres in length, and would have had a very similar lifestyle to the American alligator or Nile crocodile.

<i>Allodaposuchus</i> Extinct genus of reptiles

Allodaposuchus is an extinct genus of crocodyliforms that includes four species that lived in what is now southern Europe during the Campanian and Maastrichtian stages of the Late Cretaceous. Although generally classified as a non-crocodylian crocodylomorph, it is sometimes placed as one of the earliest true crocodylians. Allodaposuchus is one of the most common Late Cretaceous crocodylomorphs from Europe, with fossils known from Romania, Spain, and France.

<i>Borealosuchus</i> Extinct genus of reptiles

Borealosuchus is an extinct genus of crocodyliforms that lived from the Late Cretaceous to the Eocene in North America. It was named by Chris Brochu in 1997 for several species that had been assigned to Leidyosuchus. The species assigned to it are: B. sternbergii, the type species, from the Maastrichtian of Colorado, Montana, North Dakota, South Dakota, and Wyoming; B. acutidentatus, from the Paleocene of Saskatchewan; B. formidabilis, from the Paleocene of North Dakota; B. griffithi, from the Paleocene of Alberta; and B. wilsoni, from the Eocene of Wyoming. B. formidabilis is particularly well-known, represented by the remains of many individuals from the Wannagan Creek site in North Dakota.

Procaimanoidea is an extinct genus of alligatorid from the Eocene of North America. It was named posthumously in 1946 by Charles W. Gilmore; the type species is P. utahensis, from the Uintan of Utah. It is based on USNM 15996, a nearly complete skull and partial left hind leg. A second species, P. kayi, was named in 1941 by C.C. Mook as a species of Hassiacosuchus, for remains from the Bridgerian of Wyoming. It was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht. Procaimanoidea was a small alligatorid, and slightly heterodont, the last four teeth on each side of the jaws having blunt tips.

<i>Leidyosuchus</i> Genus of reptiles

Leidyosuchus is an extinct genus of alligatoroid from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is L. canadensis. It is known from a number of specimens from the middle Campanian age Dinosaur Park Formation. It was a medium-sized alligatorid, with a maximum skull length greater than 40 centimeters (16 in).

<i>Hassiacosuchus</i> Extinct genus of reptiles

Hassiacosuchus is an extinct genus of small alligatorid from the early Eocene of Germany, found at the Messel pit. It was named in 1935 by K. Weitzel, and the type species is H. haupti. A second species, H. kayi, was named in 1941 by C.C. Mook for material from the Bridgerian of Wyoming, but was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht. Hassiacosuchus may be the same as Allognathosuchus; Christopher Brochu has recommended continuing to use Hassiacosuchus.

<i>Necrosuchus</i> Extinct genus of reptiles

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<i>Allognathosuchus</i> Extinct genus of reptiles

Allognathosuchus is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921.

<i>Navajosuchus</i> Extinct genus of reptiles

Navajosuchus is an extinct genus of alligatorine crocodylian. Its fossils have been found in the Paleocene-age Nacimiento Formation of the San Juan Basin, New Mexico. It was named in 1942 by Charles C. Mook, and the original type species was N. novomexicanus. N. novomexicanus was based on AMNH 5186, a partial skull collected in 1913. Later research showed that Navajosuchus novomexicanus was the same as the earlier-named Allognathosuchus mooki. However, A. mooki does not belong to the genus Allognathosuchus, and so the name of the crocodilian becomes Navajosuchus mooki. Under whichever name is used, this animal would have been a generalized predator of the Nacimiento floodplains. It was the most common Nacimiento Formation crocodilian, found in both the Puercan and Torrejonian faunal assemblages.

<i>Asiatosuchus</i> Extinct genus of reptiles

Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.

Dinosuchus is a problematic genus of extinct alligatorid crocodilian. It was very large compared to other alligatorids, save for the giant caiman Purussaurus and its closest relatives. The genus was first described in 1876 on the basis of a vertebra from the Brazilian Amazon, the type species being named D. terror. In 1921, a new species of Dinosuchus, D. neivensis, was named based on a large mandible that was discovered in Colombia. D. neivensis was later found to be synonymous with both Brachygnathosuchus braziliensis and Purussaurus brasiliensis, being reassigned in 1924 to the senior synonym P. brasiliensis. In 1965, D. terror was proposed to be a nomen vanum.

<i>Kentisuchus</i> Extinct genus of reptiles

Kentisuchus is an extinct genus of gavialoid crocodylian, traditionally regarded as a member of the subfamily Tomistominae. Fossils have been found from England and France that date back to the early Eocene. The genus has also been recorded from Ukraine, but it unclear whether specimens from Ukraine are referable to Kentisuchus.

<i>Musturzabalsuchus</i> Extinct genus of reptiles

Musturzabalsuchus is an extinct genus of crocodylian, and one of the oldest known members of the superfamily Alligatoroidea. The generic name means "Broadened rostrum crocodile", with "Musturzabal" meaning "broadened rostrum" in Basque and "suchus" meaning "crocodile" in Greek. The type and only species is M. buffetauti, named after the French paleoherpetologist Eric Buffetaut. The material first assigned to Musturzabalsuchus in 1997 has been found from the locality of Laño in Condado de Treviño, northern Spain. Although dating back to the Late Cretaceous, the exact age of the strata in which material of Musturzabalsuchus occurs in the locality is not known: it is either Late Campanian or very Early Maastrichtian. Despite the unusually high quantity of remains belonging to the genus, the only skeletal elements known from Musturzabalsuchus are the maxilla and mandible. Some fragments of these bones have been found from the locality of Armuña in the province of Segovia that were previously referred to an unnamed trematochampsid. Like the holotype and paratype material found from Laño, these fossils, known collectively as UPUAM-502, are Campano-Maastrichtian in age. Another specimen from the Fuvelian Lignites of France has been referred to Musturzabalsuchus in 1999. However, the characteristics used to assign the material to better-known specimens of Musturzabalsuchus from Spain were questioned in a later study. Material from Musturzabalsuchus has been found more recently from Valencia, Spain, being slightly older in age than specimens from other localities, dating back to the Early or Middle Campanian.

Notocaiman is an extinct genus of alligatorid crocodylian. A fragmentary and poorly preserved left dentary found in the Peñas Coloradas Formation of Argentina that presumably dates back to the Paleocene epoch (Peligran-Riochican), is all that is known from the genus. It may be a junior synonym of Eocaiman. Similarities between the remains of Notocaiman and comparable material from the alligatoroid Listrognathosuchus have been observed, but have not been taken as evidence for synonymy. The type species, N. stromeri, was named in 1937.

Orthogenysuchus is an extinct genus of caimanine alligatorids. Fossils have been found from the Wasatch Beds of the Willwood Formation of Wyoming, deposited during the early Eocene. The type species is O. olseni. The holotype, known as AMNH 5178, is the only known specimen belonging to the genus and consists of a skull lacking the lower jaws. The braincase is filled in by the matrix and most of the suture lines between bones are indiscernible, making comparisons with other eusuchian material difficult.

<i>Pholidosaurus</i> Extinct genus of reptiles

Pholidosaurus is an extinct genus of neosuchian crocodylomorph. It is the type genus of the family Pholidosauridae. Fossils have been found in northwestern Germany. The genus is known to have existed during the Berriasian-Albian stages of the Early Cretaceous. Fossil material found from the Annero and Jydegård Formations in Skåne, Sweden and on the island of Bornholm, Denmark, have been referred to as a mesoeucrocodylian, and possibly represent the genus Pholidosaurus.

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. langi from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw.

<i>"Crocodylus" affinis</i> Species of reptile (fossil)

"Crocodylus" affinis is an extinct species of crocodyloid from the Eocene of Wyoming. Fossils were first described from the Bridger Formation by American paleontologist Othniel Charles Marsh in 1871. Marsh described the species, along with every other species of crocodyloid in the Bridger Formation, under the genus Crocodylus. The known specimen of "Crocodylus" affinis is a skull found at Grizzly Buttes, Wyoming, measuring 13 inches in length on the upper surface. Recent phylogenetic studies of crocodyloids show that "C." affinis is not a species of Crocodylus, but a genus has not yet been erected to include the species. Other Bridger species such as Crocodylus clavis and Brachyuranochampsa zangerli have been synonymized with "C." affinis.

Allodaposuchidae Extinct clade of reptiles

Allodaposuchidae is an extinct clade of eusuchians that lived in Europe during the Late Cretaceous (Santonian-Maastrichtian).

References

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  2. Mook, C. C. (1930). A new species of crocodilian from the Torrejon Beds. American Museum Novitates447:1-11.
  3. Gilmore, C. W. (1910). Leidyosuchus sternbergii, a new species of crocodile from the Cretaceous beds of Wyoming. Proceedings of the United States National Museum38(1762):485-502.
  4. Rauhe, M. and Rossmann, T. (1995). News about fossil crocodiles from the middle Eocene of Messel and Geiseltal, Germany. Halllesches Jahrbuch fur Geowissenschaften 17:18-92.
  5. Kälin, J. A. (1955). "Crocodilia". In: Piveteau, J., ed., Traité de Paléontologie, Vol. 5. Masson, Paris. pp. 695-784.
  6. Berg, D. E. (1966). Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen. Abhandlungen des Hessischen Landesamtes für Bodenforschung52:1-105.
  7. Steel, R. (1973). Handbuch der Paleoherpetologie. Vol. 16: Crocodilia. Fischer-Verlag, Portland, Oregon. 116pp.
  8. Bartels, W. S. (1980). Early Cenozoic reptiles and birds from the Bighorn Basin, Wyoming. University of Michigan Papers on Paleontology24:73-80.
  9. Nopcsa, F. (1928). Palaeontoloical notes on reptiles, VII: On the classification of the Crocodilia. Geologica Hungarica (Series Palaeontologica) 1(1):75-84.
  10. Nopcsa, F. (1928). The genera of reptiles. Palaeobiologica1:163-188.
  11. Simpson, G. G. (1937). An ancient eusuchian crocodile from Patagonia. American Museum Novitates965:1-20.