Wulagasaurus (meaning "Wulaga lizard", in reference to the discovery locality) is a genus of saurolophine hadrosaurid dinosaur from the Late Cretaceous of Heilongjiang, China. Its remains were found in a bonebed in the middle Maastrichtian-age Yuliangze Formation, dated to 69 million years ago. This bonebed is otherwise dominated by fossils of the lambeosaurine hadrosaurid (hollow-crested duckbill) Sahaliyania. Wulagasaurus was named by Pascal Godefroit and colleagues in 2008. Only partial remains are known at this time. It is one of several hadrosaurids from the Amur River region named since 2000. The type and only species to date is W. dongi, named in honor of Chinese paleontologist Dong Zhiming.
Wulagasaurus is based on GMH W184, a partial dentary (toothbearing bone of the lower jaw). Godefroit and colleagues assigned additional remains from the bonebed to their new genus, including three braincases, a cheekbone, two maxillae (the toothbearing bone of the upper jaw), another dentary, two shoulder blades, two sternal elements, two upper arm bones, and an ischium. It can be distinguished from other hadrosaurids by its slender dentary and the unique form of its upper arm, which had distinctive articulations and placements for muscle attachments. Godefroit and colleagues performed a phylogenetic analysis that suggests Wulagasaurus was the most basal saurolophine known (which would result in a long ghost lineage), and interpreted this as evidence that saurolophines and hadrosaurids in general originated in Asia, which has been supported by other finds since. As a hadrosaurid, Wulagasaurus would have been an herbivore.
In recent studies conducted by researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), along with others from Chinese Academy of Science, American Museum of Natural History, and Geological Museum of Heilongjiang Provinces, re-evaluated and re-described Wulagasaurus dongi. Based on both original and recent specimens, they concluded that Wulagasaurus shared many morphological similarities with North American taxon's Brachylophosaurus and Maiasaura, possibly forming a clade-structure within the already existing clade Brachylophosaurini. This hypothesis has been demonstrated by another phylogenetic analysis recently coming out.
Godefroit et al., 2008
Godefroit et al., 2008
Acristavus is a genus of saurolophine dinosaur. Fossils have been found from the Campanian Two Medicine Formation in Montana and Wahweap Formation in Utah, United States. The type species A. gagslarsoni was named in 2011. Unlike nearly all hadrosaurids except Edmontosaurus, Acristavus lacked ornamentation on its skull. The discovery of Acristavus is paleontologically significant because it supports the position that the ancestor of all hadrosaurids did not possess cranial ornamentation, and that ornamentation was an adaptation that later arose interdependently in the subfamilies Saurolophinae and Lambeosaurinae. It is closely related to Brachylophosaurus and Maiasaura, and was assigned to a new clade called Brachylophosaurini.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).Arkharavia
Arkharavia is a dubious genus of somphospondylan sauropod, but at least some of the remains probably belong to a hadrosaurid. It lived in what is now Russia, during the Late Cretaceous. It was described in 2010 by Alifanov and Bolotsky. The type species is A. heterocoelica.Barsboldia
Barsboldia (meaning "of Barsbold", a well-known Mongolian paleontologist) was a genus of large hadrosaurid dinosaur from the early Maastrichtian Nemegt Formation of Ömnogöv', Mongolia. It is known from a partial vertebral column, partial pelvis, and some ribs.Bonapartesaurus
Bonapartesaurus is an extinct genus of herbivorous ornithopod dinosaur belonging to Hadrosauridae, which lived in the area of the modern Argentina during the Campanian and Maastrichtian stages of the Late Cretaceous.Brachylophosaurini
Brachylophosaurini is a tribe of saurolophine hadrosaurs with known material being from N. America and potentially Asia. It contains at least four taxa; Acristavus (from Montana and Utah), Brachylophosaurus (from Montana and Alberta), Maiasaura (also from Montana), and Probrachylophosaurus (also from Montana). A hadrosaur from the Amur river, Wulagasaurus, might be a member of this tribe, but this is disputed. The group was defined by Terry A. Gates and colleagues in 2011.The clade Brachylophosaurini was defined as "Hadrosaurine ornithopods more closely related to Brachylophosaurus, Maiasaura, or Acristavus than to Gryposaurus or Saurolophus".Brachylophosaurus
Brachylophosaurus ( brə-KIL-ə-fo-SAWR-əs or brak-i-LOH-fə-SAWR-əs; meaning "short-crested lizard", Greek brachys = short + lophos = crest + sauros = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana and the Oldman Formation of Alberta, living about 78 million years ago.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.Kundurosaurus
Kundurosaurus is an extinct genus of saurolophine hadrosaurid dinosaur known from the Latest Cretaceous (probably Late Maastrichtian stage) of Amur Region, Far Eastern Russia. It contains a single species, Kundurosaurus nagornyi.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.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.Saurolophinae
Saurolophinae is a subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. However, the name Hadrosaurinae is based on the genus Hadrosaurus which was found in more recent studies to be more primitive than either lambeosaurines or other traditional "hadrosaurines", like Edmontosaurus and Saurolophus. As a result of this, the name Hadrosaurinae was dropped or restricted to Hadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae. Recent phylogenetic work by Hai Xing indicates that Hadrosaurus is placed within the monophyletic group containing all non-lambeosaurine hadrosaurids. Under this view, the traditional Hadrosaurinae is resurrected, with the Hadrosauridae being divided into two clades: Hadrosaurinae and Lambeosaurinae.
Saurolophinae was first defined as a clade in a 2010 phylogenetic analysis by Prieto-Márquez. Traditionally, the "crestless" branch of the family Hadrosauridae had been named Hadrosaurinae. However, the use of the term Hadrosaurinae was questioned in a comprehensive study of hadrosaurid relationships by Albert Prieto-Márquez in 2010. Prieto-Márquez noted that, though the name Hadrosaurinae had been used for the clade of mostly crestless hadrosaurids by nearly all previous studies, its type species, Hadrosaurus foulkii, has almost always been excluded from the clade that bears its name, in violation of the rules for naming animals set out by the ICZN. Prieto-Márquez (2010) defined Hadrosaurinae as only the lineage containing H. foulkii, and used the name Saurolophinae instead for the traditional grouping.The cladogram below follows Godefroit et al. (2012) analysis.
The following cladogram was recovered in the 2013 phylogenetic analysis by Prieto-Márquez (the relationships within Lambeosaurinae and between basal hadrosauroids aren't shown).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.