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31-496: Sabinosuchus (meaning " Sabinas crocodile") is a genus of Mesoeucrocodylian , from the Maastrichtian Escondido Formation of Coahuila , Mexico , with Sabinosuchus coahuilensis as the type species . First described as a putative dyrosaurid by Shiller II et al. (2016), it was later recovered as a pholidosaurid by Jouve & Jalil (2020). Sabinosuchus was discovered by amateur paleontologist of

62-594: A cylindrical torso, suggesting a primarily terrestrial ecology as opposed to the semi-aquatic habits of modern crocodilians and the fully marine habits of other dyrosaurids. Cerrejonisuchus is known from the Middle to Late Paleocene Cerrejón Formation. All known specimens have been found from the Cerrejón open-pit coal mine at the La Puente Pit below Coal Seam 90. The mine has also yielded remains of Titanoboa cerrejonensis ,

93-409: A dermal shield at maturity. Also, the sutures that separate the bones of the skull in both specimens are fully fused, suggesting that the individuals have reached a late ontogenic stage. In contrast, UF/IGM 32 has an unfused nasal suture, suggesting that it was less mature than the other individuals. UF/IGM 32 is also noticeably smaller than the other specimens. Relative to the entire skull length,

124-406: A diet consisting of fish, invertebrates, frogs, lizards, small snakes, and possibly mammals. The short snout of Cerrejonisuchus is thought to be an adaptation to such a generalized diet. Other long-snouted marine dyrosaurs are presumed to have had a strongly piscivorous diet consisting solely of fish. With its short snout, Cerrejonisuchus would have been able to occupy a new ecological niche in

155-522: A group of Neosuchians found in marine sediments of the Cretaceous to Early Eocene. This assignment was based on the size of the seventh dentary alveolus (smaller than the eight) and the proportions of the mandibular symphysis (approximately as wide as high). However, several problems were found by the authors. The fragmentary remains heavily limit the available characters for the phylogenetic analysis and even fewer are of value for determining its position within

186-481: A recently described 12.8 metres (42 ft) long extinct boid that is the largest known snake to have ever existed. Like Cerrejonisuchus , fossils of Titanoboa were found in a gray claystone layer directly underlying Coal Seam 90. Additional dyrosaurid material has been found from the Cerrejón Formation alongside that of Cerrejonisuchus , and is thought to represent at least two different taxa. The age of

217-403: A triangular pattern and are followed by closely spaced and smaller alveoli. The teeth are generally robust with a slight curvature towards the tip of the snout, but with better developed curviture and slight anteroposterior compression in the rear portions of the jaw (at least from the seventeenth dentary tooth onward). The initial description by Schiller thought Sabinosuchus to be a dyrosaurid,

248-465: Is a combination of Sabinas , a town near the type locality, and the Greek Souchos (crocodile). The species name is likewise based on the area the specimen was found, referring to the state of Coahuila . Sabinosuchus was a longirostrine animal, meaning its snout was proportionally long and slender. The nasal bones are unfused over their preserved length and covered in teardrop-shaped pits making it

279-688: Is known from a complete skull and mandible from the Cerrejón Formation in northeastern Colombia , which is Paleocene in age. Specimens belonging to Cerrejonisuchus and to several other dyrosaurids have been found from the Cerrejón open-pit coal mine in La Guajira . The length of the rostrum is only 54-59% of the total length of the skull, making the snout of Cerrejonisuchus the shortest of all dyrosaurids. At an estimated length of 1.22 metres (4.0 ft) to 2.22 metres (7.3 ft), Cerrejonisuchus

310-425: Is thought to represent a less mature individual. In UF/IGM 31, the neurocentral sutures of the anterior dorsal vertebrae are closed, an indication of morphological maturity. Additionally, the presence of well-developed osteoderms is likely to be an indication that the animal was mature because in living crocodylians, the osteoderms begin calcification after 1 year and grow to articulate with other osteoderms to form

341-472: The Cerrejón Formation has been dated as Middle-Late Paleocene based on carbon isotopes , pollen , spores , and dinoflagellate cysts. The section of the Cerrejón Formation from which fossils of Cerrejonisuchus have been found was likely deposited in a transitional environment, probably brackish water in a river -to- lagoonal setting. Large freshwater podocnemidid turtles and dipnoan and elopomorph fishes have also been found from this part of

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372-597: The Palaeontologos Aficionados de Sabinas A.C. (PASAC) in 2002 in Mexico. All fossils of Sabinosuchus found by the team stem from the Maastrichtian Escondido Formation , although earlier reports wrongfully believed them to stem from the underlying Olmos Formation . The material collected constitutes two individuals known from fragmentary remains that were later reassembled. Due to this the material

403-591: The Paleocene greenhouse. The presence of dyrosaurids such as Cerrejonisuchus in the Paleocene of Colombia suggests that there was a radiation of dyrosaurids in South America following the Cretaceous–Paleogene boundary (K–T boundary) and the Cretaceous–Paleogene extinction event . There may have been a dispersal from Africa to Brazil , and continued immigration into North America . Colombia can be seen as

434-982: The clade. Although it might be expected that Chenanisuchus and Cerrejonisuchus are closely related because they are the only dyrosaurids with short snouts, the results of the analysis show that snout proportions alone are not indicative of phylogenetic relatedness in dyrosaurs. Below is the cladogram from Hastings et al. (2010) showing the phylogenetic relationship of Cerrejonisuchus within Dyrosauridae: Sarcosuchus Terminonaris Elosuchus Chenanisuchus Sokotosuchus Phosphatosaurus Cerrejonisuchus Arambourgisuchus Dyrosaurus Hyposaurus Congosaurus Rhabdognathus Atlantosuchus Guarinisuchus Cerrejonisuchus likely had

465-480: The clade. The matter is further complicated by the fact that the analysis recovered Sabinosuchus in a basal position within Dyrosauridae, being recovered as a sister taxa to the brevirostrine Anthracosuchus . However, very little mandibular remains are known from basal dyrosaurs, making comparison difficult. Overall, while first described as a putative dyrosaur, Schiller and colleagues make note that this assignment

496-583: The first and second, however, reexamination by Jouve and Jalil later showed that these alveoli more likely housed the third and fourth dentary teeth given their lateral placement. These enlarged alveoli give the tip of a dentary a slightly rounded form. The better preserved of the two dentaries preserved nineteen alveoli, adding up to a total of twenty-one following the 2020 examination. Most dentary alveoli are circular in shape and range in diameter from 2.2–4.4 cm (0.87–1.73 in). The thirteenth to fifteenth differ significantly in arrangement however, emerging in

527-400: The formation. Cerrejonisuchus may have been a food source for Titanoboa , which would have lived in the same brackish water environment. The vertebrate paleofauna of the Cerrejón Formation was similar to modern neotropical riverine vertebrate faunas. During the Paleocene, river systems would have incised a coastal plain covered by a wet neotropical rainforest . The global temperature

558-413: The lateral undulations in the maxillae and premaxillae that form around the tooth sockets, or alveoli. The external nares are positioned extremely anteriorly at the very tip of the snout. The orbits are oriented anterodorsally, facing upward and slightly forward. The dentition of Cerrejonisuchus is generally homodont , although the third maxillary tooth is enlarged and the fourth is somewhat smaller than

589-423: The most ornamented skull bone. The maxillae share similar ornamentation, with a dense clutter of circular pits present towards the posterior of the bone. The sides of the bone meanwhile are much smoother by comparison. The mandible is approximately 92 cm (36 in) long, less than half of that consisting of the mandibular symphysis . The first alveoli preserved in the holotype were originally believed to be

620-403: The neotropical rainforest environment of Paleocene Colombia. The presence of homodont dentition with compressed teeth similar to those of sebecians and other terrestrial crocodylomorphs has been used as an argument for a terrestrial predatory lifestyle, though unlike other terrestrial crocodylomorphs it has a flat skull. Compared to other dyrosaurids, Cerrejonisuchus has stronger limbs and

651-893: The ninth. In addition, the size difference is not as significant as suggested by Schiller. They conclude that the features present in Sabinosuchus are much more consistent with pholidosaurids, recovering a phylogenetic tree with much stronger support than previous analysis on Sabinosuchus . Meridiosaurus vallisparadisi Dakotasuchus kingi ? French Pholidosaur Pholidosaurus schaumbergensis Pholidosaurus purbeckensis Woodbinesuchus byersmauricei Sabinosuchus coahuilensis Oceanosuchus boecensis Dakotasuchus kingi ? Terminonaris spp. MHNM-kh01 Sarcosuchus hartii Sarcosuchus imperator Chalawan thailandicus Vectisuchus leptognathus Elosuchus spp. Dyrosauridae [REDACTED] [REDACTED] [REDACTED] Sabinas As of 2015,

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682-710: The original analysis, namely Sarcosuchus , Terminonaris and Elosuchus , typically considered to be pholidosaurids (although later analysis recovered Elosuchus as closer to Dyrosaurs). Additionally, the absence of a long, curved, retroarticular process was also seen as a possible indication that Sabinosuchus wasn't a dyrosaur, but this element is not preserved in the majority of derived dyrosaurs. A later study published by Jouve and Jalil in 2020 re-evaluated several taxa previously thought to be dyrosaurs or goniopholids, including Sabinosuchus . Their analysis placed several of these taxa within Pholidosauridae, extending

713-454: The population of the city was 63,522, while the metropolitan area had a population of 177,430 inhabitants. The climate of the region is semi-arid . This article about a location in the Mexican state of Coahuila is a stub . You can help Misplaced Pages by expanding it . Cerrejonisuchus improcerus Cerrejonisuchus is an extinct genus of dyrosaurid crocodylomorph . It

744-515: The range of the group into the Maastrichtian. In their analysis, Sabinosuchus claded together with Woodbinesuchus and Oceanosuchus . Importantly, the authors note that what was described as the first and second dentary alveoli in Schiller 2016 actually represented the third and fourth alveoli. Subsequently, the smaller seventh alveolous thought to indicate dyrosaurid affinities would actually be

775-541: The rest. They are conical, labiolingually compressed, each having a relatively rounded apex. The carinae, or tooth edges, are strongly developed both anteriorly and posteriorly. The premaxillary teeth are generally thinner and longer than the maxillary teeth. Like Chenanisuchus , Cerrejonisuchus visibly lacks striations on the tooth surfaces. Unlike many other dyrosaurids, including Dyrosaurus maghribensis , Atlantosuchus coupatezi , Guarinisuchus munizi , Phosphatosaurus gavialoides , and Sokotosuchus ianwilsoni ,

806-413: The rostrum of Cerrejonisuchus is the shortest of any dyrosaurid. It, along with Chenanisuchus , are the only short-snouted dyrosaurids. The snout of Cerrejonisuchus is narrow and consistent in width from the external nares, or nostril openings, to the orbits , or eye sockets. The margin of the snout, unlike that of many long-snouted dyrosaurids, is smooth rather than festooned. "Festooned" refers to

837-404: The teeth of Cerrejonisuchus are not curved. A phylogenetic analysis of dyrosaurids by Hastings et al. (2010) placed Cerrejonisuchus relatively basally in the dyrosaur clade between Phosphatosaurus gavialoides and Arambourgisuchus khouribgaensis . Cerrejonisuchus was not found to be closely related to the other short-snouted dyrosaur Chenanisuchus , which was placed at the base of

868-464: Was catalogued under several specimen numbers. The holotype material was initially catalogued as specimens PAS 945 to PAS 949 and PAS 952 once reassembled to form an almost complete specimen. The other specimen, catalogued as PAS 950 and PAS 951, represents a part of the rostrum alongside an articulated piece of the mandible. All specimens were donated to the El Museo Muzquiz . The name Sabinosuchus

899-420: Was much warmer than it is today, based on paleoclimate models. The latitudinal temperature gradient between the equator and mid-latitudes of South America was similar to the gradient that exists today. Elevated levels of carbon dioxide in the atmosphere are thought to have caused the global greenhouse temperature. The high rainfall estimates and increased pCO 2 would have maintained the rainforest floras during

930-651: Was poorly supported. Their initial phylogenetic tree is depicted below. Chenanisuchus lateroculi Anthracosuchus balrogus Sabinosuchus coahuilensis Cerrejonisuchus improcerus Hyposaurus rogersii Phosphatosaurus gavialoides Sokotosuchus lanwilsoni Arambourgisuchus khouribgaensis Dyrosaurus maghribensis Dyrosaurus phosphaticus Atlantosuchus coupatezi Guarinisuchus munizi Rhabdognathus aslerensis Rhabdognathus keiniensis By contrast, Schiller and colleagues identified several morphological features in Sabinosuchus which it shared with taxa used as outgroups in

961-583: Was small for a dyrosaur. This size estimate is based on the dorsal skull lengths of specimens UF /IGM 29 and UF/IGM 31. Cerrejonisuchus has the shortest body length of any known dyrosaur, much smaller than that of the longest dyrosaur, Phosphatosaurus gavialoides , which was 7.22 metres (23.7 ft) to 8.05 metres (26.4 ft) in length. Currently the only known specimens of Cerrejonisuchus are UF/IGM 29 (the type specimen ), UF/IGM 30, UF/IGM 31, and UF/IGM 32. Of these, UF/IGM 29 and UF/IGM 31 are thought to represent fully mature individuals while UF/IGM 32

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