Huehuecanauhtlus is an extinct genus of hadrosauroid dinosaur known from the Late Cretaceous (Santonian stage) of Michoacán, western Mexico. It contains a single species, Huehuecanauhtlus tiquichensis.
Ramírez-Velasco et al., 2012
Ramírez-Velasco et al. 2012
Huehuecanauhtlus was first described and named by Angel Alejandro Ramírez-Velasco, Mouloud Benammi, Albert Prieto-Márquez, Jesús Alvarado Ortega and René Hernández-Rivera in 2012 and the type species is Huehuecanauhtlus tiquichensis. The generic name is derived from Náhuatl (group of dialects related to the Aztecan languages) huehuetl, meaning "ancient" and canauhtli, meaning "duck" in reference to its hadrosauroid affinities. The correct pronunciation of the generic name is "UEUE-CANA-UHh-TLUS". The specific name, tiquichensis, honors the town of Tiquicheo, for the generosity and hospitality of its people during the fieldwork season.
Huehuecanauhtlus is known only from two individuals. The holotype IGM 6253 represented by fragmentary skull (partial left maxilla and dentary fragment) and postcranial skeleton including four cervical vertebrae, nine dorsal vertebrae, four dorsal neural spines, one dorsal diapophysis, five right dorsal ribs, seven left dorsal ribs, seven sacral neural spines, seven sacral diapophyses, one caudal diapophysis, three caudal vertebrae, two caudal neural spine, eight fragmentary ossified tendons, left and right partial ilium, and left and right partial pubis. The smaller paratype, IGM 6254, is represented by fragment of left dentary, two teeth, and one cervical prezygapophysis.
Both specimens were collected at the Barranca Los Bonetes locality in Tuzantla, Michoacán. The holotype came from the sixth fossiliferous spot, whereas the paratype came from the third spot, of an unnamed formation, dating to the Santonian stage of the Late Cretaceous period, about 85.8-83.5 million years ago.
Ramírez-Velasco et al. (2012) diagnosed Huehuecanauhtlus by a unique combination of characters. For example, two teeth exposed on the occlusal plane of the rostral third and the posterior third of the dentary and maxilla, respectively. It had seven sacral vertebrae and tall neural spines of posterior vertebrae, being between 3.5 and 4 times taller than their corresponding centra. As in Claosaurus, its supraacetabular process is as long as 75% of the length of the central iliac plate, with an apex located above the posteroventral corner of the ischiac tuberosity. It differs from other hadrosauroids in possessing an extremely deflected preacetabular process of the ilium, so that the bisecting long axis of the process forms an angle less than 130° with the horizontal plane defined by the ischiac and pubic peduncles. It can be differentiated from basal hadrosauroids in having a very deep concave profile of the dorsomedial margin of the iliac plate, adjacent to the supraacetabular process. A phylogenetic analysis performed by Ramírez-Velasco et al. (2012) found a big polytomy of all hadrosauroids which are more derived than Probactrosaurus but less derived than Hadrosauridae. The exclusion of Claosaurus, Jeyawati, Levnesovia, Nanyangosaurus, Shuangmiaosaurus and Telmatosaurus from the polytomy resulted in a more resolved topology. The cladogram below shows Huehuecanauhtlus phylogenetic position among other hadrosauroids following this topology (the relationships within Hadrosauridae are not shown).
Aquilarhinus (meaning "eagle snout" after the unusual beak morphology) is a genus of hadrosaurid ornithopod dinosaur from the Aguja Formation from Texas in the United States. The type and only species is Aquilarhinus palimentus. Due to its unusual dentary, it has been inferred to have had shovel-like beak morphology, different from the beaks of other hadrosaurs. It was originally classified as a Kritosaurus sp. before being reclassified as a new genus in 2019.Aralosaurini
Aralosaurini is a tribe of basal lambeosaurine hadrosaurs endemic to Eurasia. It currently contains Aralosaurus (from the Aral sea of Kazakhstan) and Canardia (from Toulouse, Southern France).Canardia
Canardia is an extinct genus of aralosaurin lambeosaurine dinosaur known from the Late Cretaceous Marnes d’Auzas Formation (late Maastrichtian stage) of Toulouse, Haute-Garonne Department, southern France. The type species Canardia garonnensis was first described and named by Albert Prieto-Márquez, Fabio M. Dalla Vecchia, Rodrigo Gaete and Àngel Galobart in 2013.Elasmaria
Elasmaria is a clade of iguanodont ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia.Hadrosauroidea
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and all dinosaurs more closely related to them than to Iguanodon.They are from Asia, Europe and Africa. Many primitive hadrosauroids, such as the Asian Probactrosaurus and Altirhinus, have traditionally been included in a paraphyletic (unnatural grouping) "Iguanodontidae". With cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only Iguanodon and perhaps its closest relatives.Hadrosauromorpha
Hadrosauromorpha is a cohort of iguanodontian ornithopods, defined in 2014 by David B. Norman to divide Hadrosauroidea into the basal taxa with compressed manual bones and a pollex, and the derived taxa that lack them. The clade is defined as all the taxa closer to Edmontosaurus regalis than Probactrosaurus gobiensis. This results in different taxon inclusion depending on the analysis.Hadrosaurus
Hadrosaurus (; from Greek ἁδρός, hadros, meaning "bulky" or "large", and σαῦρος, sauros, meaning "lizard") is a valid genus of hadrosaurid dinosaur that lived in North America during the Late Cretaceous Period.
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Huxleysaurus (meaning "Huxley's lizard") is a genus of herbivorous styracosternan ornithopod dinosaur.Iguanodontia
Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include Camptosaurus, Dryosaurus, Iguanodon, Tenontosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodontians were one of the first groups of dinosaurs to be found. They are among the best known of the dinosaurs, and were among the most diverse and widespread herbivorous dinosaur groups of the Cretaceous period.Jaxartosaurus
Jaxartosaurus is a genus of hadrosaurid dinosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in Kazakhstan.Jeyawati
Jeyawati is a genus of hadrosauroid dinosaur which lived during the Turonian stage of the Late Cretaceous. The type species, J. rugoculus, was described in 2010, based on fossils recovered in the U.S. state of New Mexico.The holotype, MSM P4166, was discovered in the Moreno Hill Formation. A cladistic analysis indicates that Jeyawati was more plesiomorphic (ancestral) than Shuangmiaosaurus, Telmatosaurus, and Bactrosaurus, but more derived (less like the common ancestor) than Eolambia, Probactrosaurus, and Protohadros.Laiyangosaurus
Laiyangosaurus ("Laiyang lizard") is a genus of saurolophine hadrosaurid from the Late Cretaceous of China. It is known from one species, L.youngi, found in the Laiyang Basin within the province of Shandong.Lapampasaurus
Lapampasaurus is an extinct genus of hadrosaurid known from the Late Cretaceous Allen Formation (late Campanian or early Maastrichtian stage) of La Pampa Province, Argentina. It contains a single species, Lapampasaurus cholinoi.The generic name refers to the Argentine province of La Pampa. The specific name honours the late collector José Cholino. The material includes cervical, dorsal, sacral and caudal vertebrae, the forelimb girdle, and the partial hindlimb.Osmakasaurus
Osmakasaurus is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the lower Cretaceous period (Valanginian age) in what is now Buffalo Gap of South Dakota, United States. It is known from the Chilson Member of the Lakota Formation. This genus was named by Andrew T. McDonald in 2011 and the type species is Osmakasaurus depressus. O. depressus was previously referred to as Camptosaurus depressus, and was first described in 1909 by Charles W. Gilmore.Pareisactus
Pareisactus (from the Greek "pareisaktos", meaning "intruder", referring to being represented as a single element among hundreds of hadrosaurid bones) is a genus of rhabdodontid ornithopod dinosaur from the Late Cretaceous Conquès Member of the Tremp Formation in the Southern Pyrenees of Spain. The type and only species is P. evrostos, known only from a single scapula.Plesiohadros
Plesiohadros is an extinct genus of hadrosauroid dinosaur. It is known from a partial skeleton including the skull collected at Alag Teg locality, from the Campanian Djadochta Formation of southern Mongolia. The type species is Plesiohadros djadokhtaensis.Sahaliyania
Sahaliyania (from "black" in Manchu, a reference to the Amur/Heilongjiang River) is a genus of lambeosaurine hadrosaurid dinosaur (crested duckbilled dinosaur) from the Late Cretaceous of Heilongjiang, China.Tsintaosaurini
Tsintaosaurini is a tribe of basal lambeosaurine hadrosaurs native to Eurasia. It currently contains only Tsintaosaurus (from China) and Pararhabdodon (from Spain ).Koutalisaurus, also known from late Cretaceous Spain and formerly referred to Pararhabdodon
, may also be a tsintaosaurin because of its association with the latter genus; some recent work also suggests it may indeed be referrable to Pararhabdodon.Xuwulong
Xuwulong is a genus of hadrosauroid dinosaur from the Early Cretaceous period. It lived during the early Cretaceous period (Aptian-Albian age) in what is now Yujingzi Basin in the Jiuquan area, Gansu Province of northwestern China. It is known from the holotype – GSGM F00001, an articulated specimen including a complete cranium, almost complete axial skeleton, and complete left pelvic girdle from Xinminpu Group. Xuwulong was named by You Hailu, Li Daqing and Liu Weichang in 2011 and the type species is Xuwulong yueluni.