Magnapaulia is a genus of herbivorous lambeosaurine hadrosaurid dinosaurs known from the Latest Cretaceous Baja California, of northwestern Mexico. It contains a single species, Magnapaulia laticaudus. Magnapaulia was first described in 1981 as a possible species of Lambeosaurus by William J. Morris, and was given its own genus in 2012 by Prieto-Márquez and colleagues.
|Left premaxilla of the holotype|
Prieto-Márquez et al., 2012
Between 1968 and 1974, a team of the Natural History Museum of Los Angeles County headed by geologist William J. Morris excavated giant lambeosaurine remains from a site near El Rosario in Baja California. Morris named them Lambeosaurus laticaudus in 1981, based on type specimen LACM 17715, a partial skeleton with partial skull. Morris added a question mark to the front of the generic name to indicate its provisional nature: because no complete crest had been found for his species, and without it a definitive assignment could not be made. From what was known of the skull, he considered it to be most like Lambeosaurus. The specific name is derived from the Latin latus, "broad", and cauda, "tail". Morris interpreted this species as water-bound, due to features like its size, its tall and narrow tail (interpreted as a swimming adaptation), and weak hip articulations, as well as a healed broken thigh bone that he thought would have been too much of a handicap for a terrestrial animal to have survived long enough to heal. Between 1981 and 2012, other authors accepted it as a potential species of Lambeosaurus, suggested it could instead be a species of Hypacrosaurus, or questioned its validity.
In 2012 it was named as a separate genus by Albert Prieto-Márquez, Luis Chiappe, and Shantanu Joshi. The generic name is a combination of the Latin magnus, "large", and the first name of Paul G. Haaga, Jr., the president of the board of trustees of the Los Angeles County Museum of Natural History. The 2012 study indicated that the remains had been found in a layer of the El Gallo Formation, dating to the late Campanian, about 73.6 to 73 millions years old. The study referred numerous other specimens to the species: LACM 17698, 17699, 17700, 17702-17713, 17716 and 17717; LACM 20873-20876; and LACM 20883-20885. These had been found within a distance of three metres to the holotype and consist of partial skeletons, separate bones and skin impressions from several individuals, varying in size. In 2012 a complete redescription of the body parts was given.
Magnapaulia is noted for its great size and the tall profile of its tail, which had elongated chevrons and vertebral spines like those of Hypacrosaurus. Its size was estimated by its original describer as between 15 m (49.2 ft) and 16.5 m (54.1 ft) long, with a weight of up to 23 metric tons (25.4 tons); Prieto-Márquez et al. provided a smaller estimate of around 12.5 metres (41 ft), still among the longest ornithischians and representing the largest known lambeosaurine. The largest known specimen is LACM 17712, which includes a humerus with an estimated original length of 803 millimetres.
The redescription of 2012 established two autapomorphies, unique derived traits: the presence of chevrons at the tail base that were four times as long as the vertebral centra; and the possession at the tail base vertebrae of front joint processes, prezygapophyses, the inner bases of which formed a bowl-shaped depression that extended upwards into a deep trough on the front surface of the spine.
On the vertebral column, from at least the middle of the back to over the middle of the tail, a tall crest of almost continuous height was present formed by spines that were about four times as high as the vertebral centra.
Magnapaulia is among the many hadrosaurids that have preserved skin impressions; the tail of specimen LACM 17712 had some up to four centimetres wide scales, or perhaps bony osteoderms, embedded within up to one centimetre long hexagonal and smaller rounded scales.
In 2012 Magnapaulia was assigned to the Lambeosaurinae. The 2012 study contained a cladistic analysis which found it to be closest to Velafrons, also from Mexico, with this sister species forming a separate southern clade, itself the sister group of a clade of more northern Asian and North-American forms, including Lambeosaurus, Corythosaurus, Hypacrosaurus and Olorotitan. The cladogram below follows this analysis.
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.Huxleysaurus
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.Lambeosaurinae
Lambeosaurinae is a group of crested hadrosaurid dinosaurs.Lambeosaurini
Lambeosaurini, previously known as Corythosaurini, is one of four tribes of hadrosaurid ornithopods from the family Lambeosaurinae. It is defined as all lambeosaurines closer to Lambeosaurus lambei than to Parasaurolophus walkeri, Tsintaosaurus spinorhinus, or Aralosaurus tuberiferus, which define the other three tribes. Members of this tribe possess a distinctive protruding cranial crest. Lambeosaurins walked the earth for a period of around 12 million years in the Late Cretaceous, though they were confined to regions of modern day North America and Asia.Lambeosaurus
Lambeosaurus ( LAM-bee-o-SAWR-əs; meaning "Lambe's lizard") is a genus of hadrosaurid dinosaur that lived about 75 million years ago, in the Late Cretaceous period (Campanian) of North America. This bipedal/quadrupedal, herbivorous dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a hatchet. Several possible species have been named, from Canada, the United States, and Mexico, but only the two Canadian species are currently recognized as valid.
Material relevant to the genus was first named by Lawrence Lambe in 1902. Over twenty years later, the modern name was coined in 1923 by William Parks, in honour of Lambe, based on better preserved specimens. The genus has a complicated taxonomic history, in part because small-bodied crested hadrosaurids now recognized as juveniles were once thought to belong to their own genera and species. Currently, the various skulls assigned to the type species L. lambei are interpreted as showing age differences and sexual dimorphism. Lambeosaurus was closely related to the better known Corythosaurus, which is found in slightly older rocks, as well as the less well-known genera Hypacrosaurus and Olorotitan. All had unusual crests, which are now generally assumed to have served social functions like noisemaking and recognition.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.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.Velafrons
Velafrons (meaning "sailed forehead") is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. It is known from a mostly complete skull and partial skeleton of a juvenile individual, with a bony crest on the forehead. Its fossils were found in the late Campanian-age Cerro del Pueblo Formation (about 72 million years old), near Rincon Colorado, Coahuila, Mexico. The type specimen is CPC-59, and the type species is V. coahuilensis.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.