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.[1]

Temporal range: Campanian-Maastrichtian
~80–66 Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Suborder: Ornithopoda
Family: Hadrosauridae
Subfamily: Saurolophinae
Tribe: Saurolophini
Genus: Bonapartesaurus
Cruzado Caballero & Powell 2017
Type species
B. rionegrensis
Cruzado Caballero & Powell 2017

Discovery and naming

The remains were excavated by the Argentine paleontologist Jaime Powell and collaborators in 1984 and described by him in 1987, where he identified the dinosaur remains as a possible "indeterminate lambeosaurine", comparing it mainly with the genera Hypacrosaurus and Barsboldia due to great size of the neural spines.[2]

In 2010, Rubén D. Juárez Valieri and his team erected a new genus and hadrosaurid species called Willinakaqe salitralensis from different materials found in 2 different locations (Salitral Moreno and Islas Malvinas) of the Allen Formation,[3] which are mostly housed in the collection of the Carlos Ameghino Provincial Museum, where the specimen was examined by Powell, and was made the paratype of this new genus, in addition to the holotype of Lapampasaurus as material attributed to W. salitralensis from the second locality and housed in the Provincial Museum of Natural History, in the province of La Pampa.[4]

Later, the Spanish paleontologist Penélope Cruz-Caballero and the Argentine Rodolfo Coria reviewed the material attributed to the genus Willinakaqe in 2016, where they concluded that fossils may represent more than one taxon of hadrosaurid and that the characteristics used in the diagnosis would not be valid. Also, the specimen is not preserved in good condition in addition to being incomplete, and therefore non-diagnostic, degrading it to the status of "indeterminate Hadrosauridae" and making Willinakaqe salitrensis a Nomen vanum.[5]

In 2017 Cruzado-Caballero and Powell reassign the paratype of W. salitralensis to its own genus and species, Bonapartesaurus rionegrensis, converting the former into a chimera of different hadrosaurids, and hence, an invalid name.[1]


The holotype specimen MPCA-Pv SM2/1-71, consists of a partial skeleton including 4 dorsal vertebrae, a complete sacrum, 8 anterior caudal vertebrae, 9 medial caudal vertebrae, 2 blocks with 5 medial caudal vertebrae each, 18 haemal arches, 3 dorsal ribs, a distal fragment of the right scapula, a distal fragment of the left humerus, a left ulna, a right ilium, a nearly complete left pubis, distal fragments of both ischia, both femurs, tibias, and fibulae, a left astragalus, a right calcaneus, an almost complete articulated left foot and two blocks with tendons.[1] All the material present was extracted from the Salitral Moreno site of the Río Negro province in southern Argentina, from the lower member of the Allen Formation, which dates to the Late Cretaceous (Campanian to Maastrichtian).

Bonapartesaurus is characterized by the following combination of unique characters: the proportion between the height of the neural, sacral and centrum spines is greater than 3.5; the neural spines of the anterior part of the caudal vertebrae are extremely long (between three and a half and four times the height of the centrum) and evenly the distal expansion; a pre-acetabular process slightly flexed ventrally, with the angle greater than 150°; the proportion between the maximum dorsoventral depth of the posterior end of the dorsoventral preacetabular process and the distance from the pubic peduncle to the dorsal margin of the iliac bone is inferior to 0,50; The ratio between height and anteroposterior dorsoventral length of the iliac lamina is 0.8 or higher; an asymmetric lateral profile of the supraacetabular process; the posterior portion of the mediolateral postacetabular process markedly thicker as a result of the dorsomedial torsion of the postacetabular process; an expanded cnemial crest limited anteriorily to the proximal end of the tibia; and the articular surface of the astragalus for the internal malleolus of the tibia is moderately expanded medially, articulating with only a part of the ventral surface of the tibial internal malleolus.[1]


The only phylogenetic analysis of Bonapartesaurus follows Paul Sereno's definition for Hadrosauridae from 1998,[6] in addition to using the traditional classification of Hadrosaurinae (prior to the consensus of Prieto-Marquez in 2010[7]), which includes all non-crested hadrosaurids along with the fragmentary genus Hadrosaurus within the same subfamily. It is also placed within the Saurolophini tribe, being more derived than Prosaurolophus, but more basal than Saurolophus spp., in contrast to the tentative classification of Willinakaqe within the Kritosaurini tribe.[3] The following cladogram is based on the phylogenetic analysis of Cruzado-Caballero & Powell in 2017. (Relations with Lambeosaurinae as well as with Hadrosauroidea are not shown here).[1]

Hadrosaurinae / Saurolophinae

Hadrosaurus foulkii

Wulagasaurus dongi

Acristavus gagslarsoni

Maiasaura peeblesorum

Brachylophosaurus canadensis

Kritosaurus navajovius

Gryposaurus notabilis

Gryposaurus monumentensis

Gryposaurus incurvimanus

Gryposaurus latidens

Kerberosaurus manakini

Shantungosaurus giganteus

Edmontosaurus regalis

Edmontosaurus saskatchewanensis

Edmontosaurus annectens

Lophorhothon atopus

Prosaurolophus maximus

Bonapartesaurus rionegrensis

Saurolophus osborni

Saurolophus angustirostris

See also


  1. ^ a b c d e Cruzado-Caballero, P.; Powell, J. E. (2017). "Bonapartesaurus rionegrensis, a new hadrosaurine dinosaur from South America: implications for phylogenetic and biogeographic relations with North America". Journal of Vertebrate Paleontology (In press): 1–16. doi:10.1080/02724634.2017.1289381.
  2. ^ Powell, J. E. (1987). "Hallazgo De Un Dinosaurio Hadrosáurido (Ornithischia, Ornithopoda) En La Formación Allen (Cretácico Superior) De Salitral Moreno, Provincia De Río Negro, Argentina". Décimo Congreso Geológico Argentino. Actas 3: 149–152.
  3. ^ a b Juárez-Valieri, R. D.; Haro, J.; Fiorelli, L. & Calvo, J. (2010). "A new hadrosauroid (Dinosauria: Ornithopoda) from the Allen Formation (Late Cretaceous) of Patagonia, Argentina" (PDF). Revista del Museo Argentino de Ciencias Naturales n.s. 11 (2): 217–231. Archived from the original (PDF) on 2011-09-03. Retrieved 2017-05-16.
  4. ^ Coria, R. A.; González-Riga, B.; Casadío, S. (2012). "Un Nuevo Hadrosáurido (Dinosauria, Ornithopoda) De La Formación Allen, Provincia De La Pampa, Argentina". Ameghiniana. Tomo 49 (4): 552–572. ISSN 0002-7014.
  5. ^ Cruzado Caballero, P.; & Coria, R. A. (2016). "Revisiting the hadrosaurid diversity of the Allen Fm.: Re-evaluation of the taxonomic validity of Willinakaqe salitralensis (Ornithopoda, Hadrosauridae) from Salitral Moreno, Río Negro Province, Argentina". Ameghiniana. 53 (2): 231–237. doi:10.5710/AMGH.25.09.2015.2943.
  6. ^ Sereno, P. C. (1998). "A rationale for phylogenetic definitions, with application to the higher-level taxonomy of Dinosauria". Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 210 (1): 41–83.
  7. ^ Prieto-Márquez, A. (2010). "Global phylogeny of Hadrosauridae (Dinosauria: Ornithopoda) using parsimony and Bayesian methods" (PDF). Zoological Journal of the Linnean Society. 159 (2): 435–502. doi:10.1111/j.1096-3642.2009.00617.x.

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 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).


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".


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 is a clade of iguanodont ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia.


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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 is a genus of hadrosaurid dinosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in Kazakhstan.


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.


Koshisaurus is a monospecific genus of basal hadrosauroid from the Kitadani Formation in Japan. The discovery of the genus suggests that hadrosauroids had higher diversity along the eastern margin of Asia in the Early Cretaceous. "Koshi" means an old Japanese regional name including Fukui prefecture where fossils of the genus were discovered.


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 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.


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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.


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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.


Saurolophini is a tribe of saurolophine hadrosaurid native to the Americas and Asia. It includes Saurolophus (from Canada and Mongolia), Augustynolophus (from the United States), and Prosaurolophus (from Alberta, Canada, and Montana, U.S.). Kerberosaurus and Kundurosaurus may also be members. Bonapartesaurus, a hadrosaurid from Argentina, also has been identified as a member of this tribe.Fossils of saurolophins have been found in Canada, the United States and Asia, with the North American fossils being older than the Asian, suggesting saurolophins migrated intra-continentally.


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.


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