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.[1]

Kundurosaurus
Temporal range: Late Cretaceous, 67–66 Ma
Kundurosaurus
Restoration of the skull
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Suborder: Ornithopoda
Family: Hadrosauridae
Subfamily: Saurolophinae
Genus: Kundurosaurus
Godefroit et al., 2012
Type species
Kundurosaurus nagornyi
Godefroit et al., 2012

Description

Kundurosaurus dentaries
Dentaries AENM 2/846 (A-B) and AENM 2/902 (C-D).

Kundurosaurus is a saurolophine diagnosed by four autapomorphies, unique derived traits. It has a prominent and thick ridge on the lateral side of the nasal that borders caudally the circumnasal depression and invades the caudal plate of the nasal. Its caudal buttress of the proximal head of the scapula is oriented quite laterally, parallel to the pseudoacromial process. The preacetabular process of the ilium is straight and only moderately deflected ventrally by an angle of 160°. It does not reach the level of the plane formed by the bases of the iliac and pubic peduncles. Finally, with Kundurosaurus the axis of the postacetabular process of the ilium is strongly twisted along its length, so that its lateral side progressively faces dorsolaterally.[1]

Discovery

Kundurosaurus reconstructed endocranial
Endocranial reconstruction of AENM 2/121 based on a CT scan.

Kundurosaurus is known from holotype AENM 2/921, a partial, disarticulated skull, including a nearly complete braincase (AENM 2/921 1-2), two quadrates (3-4), squamosal (5), postorbital (6), frontal (7) and parietal (8) bones. The referred specimens are AENM 2/45-46, two jugals; AENM 2/83-84, 2/86, maxillae; AENM 2/57-58, nasals; AENM 2/48, postorbital; AENM 2/19, quadrate; AENM 2/121, 2/928 partial braincases; AENM 2/846, 2/902, dentaries; AENM 2/906, scapula; AENM 2/913, sternal; AENM 2/117, 2/903, 2/907-908, humeri; AENM 2/905, ulna; AENM 2/904, radius; AENM 2/922, nearly complete pelvic girdle and associated sacral elements. These were found at the same level as the holotype, but may belong to other individuals. All specimens are housed in the Amur Natural History Museum of the Institute of Geology and Nature Management, Russia.[1]

Kundurosaurus was first described and named by Pascal Godefroit, Yuri L. Bolotsky and Pascaline Lauters in 2012 and the type species is Kundurosaurus nagornyi. The generic name is derived from Kundur, the type and only known locality, and sauros, "lizard" in Ancient Greek. The specific name, nagornyi, honors V.A. Nagorny from the Far Eastern Institute of Mineral Resources, for discovering the Kundur locality in 1990.[1]

Kundurosaurus is located in Heilongjiang
Wulaga
Wulaga
Jiayin
Jiayin
Kundur
Kundur
Blagoveschensk
Blagoveschensk
Location of hadrosaur localities in the Maastrichtian Zeya-Bureya Basin. Map of Heilongjiang, China, as well as the Amur Region of Russia. Blue dots represent the Yuliangze Formation, and red dots represent the Udurchukan Formation. Wulaga is home to Wulagasaurus and Sahaliyania, Jiayin to Charonosaurus, Kundur to Kundurosaurus and Olorotitan, and Blagoveschensk to Kerberosaurus and Amurosaurus.

All Kundurosaurus specimens were collected in the Kundur locality. The site belongs to the Wodehouseia spinataAquilapollenites subtilis palynozone, dating to the Maastrichtian stage, probably the Late Maastrichtian, of the Late Cretaceous period, about 67-66 million years ago. The Kundur site was discovered by Vladimir A. Nagorny in 1990. He collected fossil bones in a road section along the Chita – Khabarovsk highway near the village of Kundur and sent them to Yuri L. Bolotsky. Large-scale excavations started at Kundur in 1999. Besides the abundant Olorotitan arharensis material, it has yielded many disarticulated saurolophine specimens. All these specimens were assigned to Kundurosaurus because the describers considered the recovered material to be homogeneous, and suggested that there is no reason to believe that more than one single saurolophine taxon lived in the Kundur area by latest Cretaceous period.[1]

Kundur is one of four rich dinosaur localities that have been discovered in the southeastern part ("Lower Zeya depression") of Zeya-Bureya sedimentary basin, eastern Asia: Jiayin and Wulaga localities are located in the Yuliangze Formation of northern Heilongjiang Province, China and Blagoveschensk and Kundur localities are located in the Udurchukan Formation of southern Amur Region, Russia. In each locality, the dinosaur fauna is largely dominated by lambeosaurine hadrosaurids (Charonosaurus jiayinensis and some non-diagnostic material of Mandschurosaurus amurensis from Jiayin, Sahaliyania from Wulaga, Amurosaurus from Blagoveschensk, and Olorotitan from Kundur),[1] but the indeterminate hadrosaurid Arkharavia,[2] from Kundur, and saurolophine (non-crested or solid-crested) hadrosaurids are also represented (Saurolophus kryschtofovici and other non-diagnostic material of M. amurensis from Jiayin, Wulagasaurus from Wulaga, Kerberosaurus from Blagoveschensk and Kundurosaurus from Kundur).[1]

Classification

Kundurosaurus pelvic girdle
Pelvic girdle of Kundurosaurus: left pubis AENM 2/922-5L (A), left ischium AENM 2/922-3L (B) and the autapomorphic left ilium AENM 2/922-7L (C) in lateral view.

A phylogenetic analysis of saurolophines performed by Godefroit, Bolotsky & Lauters (2012) indicates that Kundurosaurus is nested within a clade including Edmontosaurini and Saurolophini, possibly as a sister-taxon of Kerberosaurus. It is based on the data matrix of Prieto-Márquez (2010), however Prieto-Márquez (2010) recovered Edmontosaurini as a sister-taxon of a monophyletic clade formed by Saurolophini and Kritosaurini while in Godefroit et al. (2012) the Edmontosaurini + Saurolophini clade is well supported and excludes Kritosaurini.[1]

The position of Kundurosaurus within Edmontosaurini collapses when fragmentary taxa are excluded from the analysis. In the full analysis, Kundurosaurus is placed as the sister-taxon of Kerberosaurus, which is known from the same region. It may therefore be postulated that K. nagornyi is a second species of the genus Kerberosaurus. This clade, however, is very weakly supported and synapomorphies uniting both taxa can only been found under optimization. Furthermore, although overlapping materials between the genera are limited to their partial skulls, according to Godefroit et al. (2012) Kundurosaurus can be differentiated from Kerberosaurus on the basis of the rostrocaudally longer and more robust dorsal maxillary process, more robust and more curved downwards nasal, much more robust and proportionally higher quadrate and the strong ridge extends obliquely along the lateral side of the exoccipital condyloid in Kundurosaurus. Additionally, the frontals of Kerberosaurus are particularly narrow and do not participate in the orbital margin, the rostral margin of the parietal is depressed around the contact area with the frontals, and Kerberosaurus has hook-like palatine process.[1]

Kundurosaurus scapula
Scapula
Kundurosaurus jugals
Jugals
Kundurosaurus nasals
Right nasals

On the other hand, Xing et al. (2014) considered Kundurosaurus nagornyi to be a junior synonym of Kerberosaurus manakini on the basis of their co-occurrence within the same formation and presence of shared characters in their skeletons.[3]

The cladogram below follows Godefroit et al. (2012) analysis.[1]

Bactrosaurus

 Hadrosauridae 
 Hadrosaurinae 

Hadrosaurus

Lophorhothon

 Saurolophidae 

Lambeosaurinae

 Saurolophinae 

Wulagasaurus

 Brachylophosaurini 

Acristavus

Maiasaura

Brachylophosaurus

Kritosaurus

Gryposaurus latidens

Gryposaurus notabilis

Gryposaurus monumentensis

 Saurolophini 

Prosaurolophus

Saurolophus angustirostris

Saurolophus osborni

 Edmontosaurini 

Kerberosaurus

Kundurosaurus

Edmontosaurus annectens

Edmontosaurus regalis

See also

References

  1. ^ a b c d e f g h i j Godefroit, P.; Bolotsky, Y. L.; Lauters, P. (2012). Joger, Ulrich (ed.). "A New Saurolophine Dinosaur from the Latest Cretaceous of Far Eastern Russia". PLoS ONE. 7 (5): e36849. doi:10.1371/journal.pone.0036849. PMC 3364265. PMID 22666331.
  2. ^ Godefroit, P. (2011). "Osteology and relationships of Olorotitan arharensis, a hollowcrested hadrosaurid dinosaur from the latest Cretaceous of Far Eastern Russia". Acta Palaeontologica Polonica. doi:10.4202/app.2011.0051.
  3. ^ Xing, Hai; Zhao, Xijin; Wang, Kebai; Li, Dunjing; Chen, Shuqing; Mallon, Jordan C; Zhang, Yanxia; Xu, Xing (2014). "Comparative osteology and phylogenetic relationship of Edmontosaurus and Shantungosaurus (Dinosauria: Hadrosauridae) from the Upper Cretaceous of North America and East Asia". Acta Geologica Sinica-English Edition. 88 (6): 1623–1652. doi:10.1111/1755-6724.12334.
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.

Edmontosaurini

Edmontosaurini are a tribe of saurolophine hadrosaurs that lived in the Northern Hemisphere during the Late Cretaceous period. It currently contains Edmontosaurus (from the United States and Canada), Ugrunaaluk (from Alaska, U.S.), and Shantungosaurus (from Shandong, China), though Anatosaurus might be a distinct genus. Kerberosaurus and Kundurosaurus from Russia could also be members though are more likely saurolophins.

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.

Kerberosaurus

Kerberosaurus (meaning "Kerberos lizard") was a genus of saurolophine duckbill dinosaur from the late Maastrichtian-age Upper Cretaceous Tsagayan Formation of Blagoveshchensk, Amur Region, Russia (dated to 66 million years ago). It is based on bonebed material including skull remains indicating that it was related to Saurolophus and Prosaurolophus.

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.

Saurolophini

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.

Shantungosaurus

Shantungosaurus, meaning "Shandong Lizard", is a genus of saurolophine hadrosaurid dinosaurs found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China. The stratigraphic interval of Shantungosaurus ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. Shantungosaurus is so far the largest hadrosauroid taxon in the world: the greatest length of its femur is about 1.7 m, and the greatest length of its humerus is about 0.97 m.

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.

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