Levnesovia, Sues & Averianov, 2009

Norman, David B., 2015, On the history, osteology, and systematic position of the Wealden (Hastings group) dinosaur Hypselospinus fittoni (Iguanodontia: Styracosterna), Zoological Journal of the Linnean Society 173 (1), pp. 92-189 : 158-159

LEVNESOVIA TRANSOXIANA SUES & AVERIANOV, 2009

Levnesovia comprises a partial skull roof and braincase, supplemented by a range of referred cranial and postcranial elements collected at Dzharakuduk, Uzbekistan, from the Bissekty Formation (middle−late Turonian).

Teeth, jaws, and cranial skeleton

Dentary teeth in lingual aspect are relatively narrow and diamond-shaped, and strongly resemble those described in Probactrosaurus (Norman, 2002) and Bactrosaurus ( Godefroit et al., 1998) . A prominent primary ridge is positioned slightly distally on the crown and there is an indistinct secondary ridge on the mesial portion of the crown; the coronal region possesses a distinct ‘shoulder’. Maxillary crowns are lanceolate and retain a remnant shoulder along the coronal margin with a very prominent primary ridge and no subsidiary ridges. The predentary has a crudely denticulate margin and a pair of large vascular foramina on either side of the midline, with broad, oblique vascular channels (the general configuration resembles that described in Probactrosaurus ). The dentary ramus is comparatively slender and slightly arched anteriorly (as in Hy. fittoni ); there is a short diastema and the alveolar wall is marked by inclined, parallel tooth grooves. The alveolar trough extends medial to the coronoid process, from which it is separated by a horizontal shelf and the tooth magazine is reported to terminate approximately level with the apex of the coronoid process. The surangular is reported to lack a foramen.

The ventral half of the quadrate has a laterally expanded condylar region that is stepped so that it forms a rounded lateral condyle separated by a saddle-like region from the flatter medial articular surface. The quadrate embayment appears to be wide and the paraquadrate foramen is completely closed by the quadratojugal. The jugal is tapers anteriorly and has a broad, flat facet for its contact with the maxilla – there is no evidence of an ectopterygoid facet. The skull roof is broad and flat and a short section of the frontal is exposed in the upper rim of the orbit. In almost every respect, the skull roof and braincase resemble those seen in Probactrosaurus and Bactrosaurus .

Postcranial skeleton

The vertebrae are poorly preserved, but the dorsals have the low centrum profile that is typical of derived iguanodontians. The prepubic process is laterally compressed, deep, and distally expanded, unlike that seen in Hy. fittoni . The distal femoral articular condyle has an almost entirely enclosed extensor intercondylar groove and the pedal unguals are notably short and broadly rounded in plan view ( Sues & Averianov, 2009: supplementary material 1, fig. t); these features contrast markedly with those seen in Hy. fittoni .