''Kundurosaurus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

saurolophine 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 Had ...

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which incl ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

known from the Latest Cretaceous (probably Late

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

stage) of

Amur Region Amur Oblast ( rus, Аму́рская о́бласть, r=Amurskaya oblast, p=ɐˈmurskəjə ˈobləsʲtʲ) is a federal subject of Russia (an oblast), located on the banks of the Amur and Zeya Rivers in the Russian Far East. The administrative ...

, Far Eastern

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

. It contains a single species, ''Kundurosaurus nagornyi''.

Description

''Kundurosaurus'' was a medium-sized hadrosaur, measuring long and weighing . It is a saurolophine diagnosed by four

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

, 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 The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

is oriented quite laterally, parallel to the pseudoacromial process. The preacetabular process of the

ilium Ilium or Ileum may refer to: Places and jurisdictions * Ilion (Asia Minor), former name of Troy * Ilium (Epirus), an ancient city in Epirus, Greece * Ilium, ancient name of Cestria (Epirus), an ancient city in Epirus, Greece * Ilium Building, a ...

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.

Discovery

''Kundurosaurus'' is known from

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

AENM 2/921, a partial, disarticulated

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

, including a nearly complete

braincase In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skul ...

(AENM 2/921 1-2), two quadrates (3-4),

squamosal The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone. In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...

(5),

postorbital The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some v ...

(6),

frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and ea ...

(7) and parietal (8) bones. The referred specimens are AENM 2/45-46, two jugals; AENM 2/83-84, 2/86,

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The ...

e; AENM 2/57-58,

nasals In phonetics, a nasal, also called a nasal occlusive or nasal stop in contrast with an oral stop or nasalized consonant, is an occlusive consonant produced with a lowered velum, allowing air to escape freely through the nose. The vast majority ...

; 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 The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

; AENM 2/905,

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

; AENM 2/904,

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

; 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 The Amur (russian: река́ Аму́р, ), or Heilong Jiang (, "Black Dragon River", ), is the world's tenth longest river, forming the border between the Russian Far East and Northeastern China (Inner Manchuria). The Amur proper is lon ...

, Russia. ''Kundurosaurus'' was first described and named by

Pascal Godefroit Pascal Godefroit is a Belgian paleontologist. He discovered dinosaurs like ''Olorotitan'' in 2003. Godefroit is the director of earth and life sciences at the Royal Belgian Institute of Natural Sciences. See also *Taxa named by Pascal Godefroit ...

, Yuri L. Bolotsky and Pascaline Lauters in

2012 File:2012 Events Collage V3.png, From left, clockwise: The passenger cruise ship Costa Concordia lies capsized after the Costa Concordia disaster; Damage to Casino Pier in Seaside Heights, New Jersey as a result of Hurricane Sandy; People gather ...

. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

is ''Kundurosaurus nagornyi''. The generic name is derived from ''Kundur'', the type and only known locality, and ''sauros'', "lizard" in

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

. The specific name, ''nagornyi'', honors V.A. Nagorny from the Far Eastern Institute of Mineral Resources, for discovering the Kundur locality in 1990. All ''Kundurosaurus'' specimens were collected in the Kundur locality. The site belongs to the ''Wodehouseia spinata'' – ''Aquilapollenites subtilis'' palynozone, dating to the

stage, probably the Late Maastrichtian, of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

, about 67-66

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (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. 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 The Yuliangze Formation, or Yuliangzi Formation, is a geological formation in Heilongjiang, China whose strata date back to the early-middle Maastrichtian. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampe ...

of northern

Heilongjiang Province Heilongjiang () formerly romanized as Heilungkiang, is a province in northeast China. The standard one-character abbreviation for the province is (). It was formerly romanized as "Heilungkiang". It is the northernmost and easternmost province ...

, China and Blagoveschensk and Kundur localities are located in the

Udurchukan Formation The Udurchukan Formation is a geological formation located in Amur Region, Far East Russia. Based on palynomorphs such as ''Wodehouseia spinata'' the Udurchukan is considered of Maastrichtian age of the Late Cretaceous, during the Cretaceous P ...

of southern

. In each locality, the dinosaur fauna is largely dominated by

lambeosaurine Lambeosaurinae is a group of crested hadrosaurid dinosaurs. Classification Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini (''Parasaurolophus'', '' Charonosaurus'', others (?).) and Lambeosaurini ('' ...

hadrosaurids ('' Charonosaurus jiayinensis'' and some non-diagnostic material of '' Mandschurosaurus amurensis'' from Jiayin, ''

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. Discovery Its remains were ...

'' from Wulaga, ''

Amurosaurus ''Amurosaurus'' (; "Amur lizard") is a genus of lambeosaurine hadrosaurid dinosaur found in the latest Cretaceous period (66 million years ago)Godefroit, P., Lauters, P., Van Itterbeeck, J., Bolotsky, Y. and Bolotsky, I.Y. (2011). "Recent advanc ...

'' from Blagoveschensk, and ''

Olorotitan ''Olorotitan'' was a genus of lambeosaurine duckbilled dinosaur from the middle or latest Maastrichtian-age Late Cretaceous, whose remains were found in the Udurchukan Formation beds of Kundur, Amur River Region, Far Eastern Russia. The type, an ...

'' from Kundur), but the indeterminate hadrosaurid ''

Arkharavia ''Arkharavia'' (meaning "Arkhara road") 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 Al ...

'', from Kundur, and

(non-crested or solid-crested) hadrosaurids are also represented ('' Saurolophus kryschtofovici'' and other non-diagnostic material of ''M. amurensis'' from Jiayin, ''

Wulagasaurus ''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 Maastrichtia ...

'' from Wulaga, ''

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).Godefroi ...

'' from Blagoveschensk and ''Kundurosaurus'' from Kundur).

Classification

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis of saurolophines performed by Godefroit, Bolotsky & Lauters (2012) indicates that ''Kundurosaurus'' is nested within a clade including

Edmontosaurini Edmontosaurini are a tribe of saurolophine hadrosaur dinosaurs that lived in the Northern Hemisphere during the Late Cretaceous period. It currently contains ''Edmontosaurus'' (from Canada and the United States), ''Shantungosaurus'' and ''Laiyang ...

and

Saurolophini Saurolophini is a tribe of saurolophine hadrosaurids 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, ...

, 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 Kritosaurini is a tribe of saurolophine hadrosaurid dinosaurs from the Late Cretaceous. Discovery and naming The first member of the group discovered and named was ''Kritosaurus''; it was named by paleontologist Barnum Brown in 1910. Four years l ...

while in Godefroit ''et al.'' (2012) the Edmontosaurini + Saurolophini clade is well supported and excludes Kritosaurini. 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. Kundurosaurus scapula

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. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below follows Godefroit ''et al.'' (2012) analysis.

References

{{Taxonbar, from=Q2663595 Saurolophines Late Cretaceous dinosaurs of Asia Fossil taxa described in 2012 Taxa named by Pascal Godefroit Maastrichtian genus first appearances Maastrichtian genus extinctions Ornithischian genera