[D] Kundurosaurus nagornyi [sG] [T]
Godefroit, Bolotsky & Lauters 2012
Cretaceous Late Maastrichtian
Ornithischia Ornithopoda Hadrosauridae Hadrosaurinae Gryposaurini Saurolophini
Udurchukan Formation, Tsagayan Group, Amur Region, Far Eastern Russia
Four main dinosaur sites have been investigated in latest Cretaceous deposits from the Amur/Heilongjiang Region: Jiayin and Wulaga in China (Yuliangze Formation), Blagoveschensk and Kundur in Russia (Udurchukan Formation). More than 90% of the bones discovered in these localities belong to hollow-crested lambeosaurine saurolophids, but flatheaded saurolophines are also represented: Kerberosaurus manakini at Blagoveschensk and Wulagasaurus dongi at Wulaga.
Herein we describe a new saurolophine dinosaur, Kundurosaurus nagornyi gen. et sp. nov., from the Udurchukan Formation (Maastrichtian) of Kundur, represented by disarticulated cranial and postcranial material. This new taxon is diagnosed by four autapomorphies.
A phylogenetic analysis of saurolophines indicates that Kundurosaurus nagornyi is nested within a rather robust clade including Edmontosaurus spp., Saurolophus spp., and Prosaurolophus maximus, possibly as a sistertaxon for Kerberosaurus manakini also from the Udurchukan Formation of Far Eastern Russia. The high diversity and mosaic distribution of Maastrichtian hadrosaurid faunas in the Amur-Heilongjiang region are the result of a complex palaeogeographical history and imply that many independent hadrosaurid lineages dispersed without any problem between western America and eastern Asia at the end of the Cretaceous.
AENM 2/921, a partial, disarticulated skull.
AENM 2/45, 2/46, jugals; AENM 2/83, 2/84, 2/86, maxillae; AENM 2/57, 2/58, nasals; AENM 2/48, postorbital; AENM 2/19, quadrate; AENM 2/121, 2/928 partial braincases; AEHM 2/846, 2/902, dentaries; AENM 2/906, scapula; AENM 2/913, sternal; AENM 2/117, 2/903, 2/907, 2/908, humeri; AENM 2/905, ulna; AENM 2/904, radius; AENM 2/922, nearly complete pelvic girdle and associated sacral elements.
Locality and horizon
Kundur (N49u04957.50/E130u51934.10), Amur Region, Far Eastern Russia. Udurchukan Formation (Wodehouseia spinata - Aquilapollenites subtilis palynozone), ?Late Maastrichtian, Late Cretaceous.
Kundurosaurus, from Kundur, the type-locality, and the transliterated Greek sauros (lizard); nagornyi, in honour of V.A. Nagorny (Far Eastern Institute of Mineral Resources, FEB RAS), who discovered the Kundur locality.
(as for genus by monotypy). Saurolophinae characterized by the following autapomorphies: 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; caudal buttress of proximal head of scapula oriented quite laterally, parallel to the pseudoacromial process; preacetabular process of ilium straight and only moderately deflected ventrally (angle of ventral deflection: 160u): it does not reach the level of the plane formed by the bases of the iliac and pubic peduncles; axis of the postacetabular process strongly twisted along its length, so that its lateral side progressively faces dorsolaterally.