A new basal hadrosauroid dinosaur from the Late Cretaceous of Uzbekistan and the early radiation of duck-billed dinosaurs

Abstract

Levnesovia transoxiana gen. et sp. nov., from the Late Cretaceous (Middle-Late Turonian) of Uzbekistan, is the oldest well-documented taxon referable to Hadrosauroidea sensu Godefroit et al. It differs from a somewhat younger and closely related Bactrosaurus from Inner Mongolia (China) by a tall sagittal crest on the parietals and the absence of club-shaped dorsal neural spines in adult specimens. Levnesovia, Bactrosaurus and possibly Gilmoreosaurus represent the earliest radiation of Hadrosauroidea, which took place during the Cenomanian-Turonian and possibly in North America. The second, Santonian-age radiation of Hadrosauroidea included Aralosaurus, Hadrosauridae and lineages leading to Tanius (Campanian) and Telmatosaurus (Maastrichtian). Hadrosauridae appears to be monophyletic, but Hadrosaurinae and Lambeosaurinae originated in North America and Asia, respectively.

Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria)

“…), rajiforms ( Myledaphus tritus ), lamniforms ( Scapanorhynchus sp. ), acipenseriforms, amiiforms, lepisosteiforms ( Atractosteus turanensis ), aspidorhynchiforms, pholidophoriforms, ichthyodectiforms ( Aidachar paludalis ), albuliforms, diverse salamanders and frogs, macrobaenid, adocid, trionychid (two taxa) and lindholmemydid turtles, lizards, crocodyliforms, ankylosaurs ( Bissektipelta archibaldi ), ornithopods ( Levnesovia transoxiana ), neoceratopsians ( Turanoceratops tardabilis ), sauropods, non-avian theropods, birds and mammals (Multituberculata, Spalacotheriidae, Deltatheridiidae, Asioryctitheria, Paranyctoides quadrans , Zhelestidae, Zalambdalestidae) (Riabinin 1931, 1935; Kurzanov 1976; Nesov and Trofimov 1979; Nesov and Khosatzky 1980; Nesov 1981a, b; 1982, 1984a, b, c, 1985a, b, 1986a, b, 1987a, b, 1988a, b, c, d, 1989, 1990b, 1992a, b, 1995, 1997; Nesov and Borkin 1983; Mertinene and Nesov 1985, 1991; Martinson et al 1986; Nesov and Mertinene 1986; Nesov et al 1989, 1998; Nesov and Yarkov 1989; Kielan-Jaworowska and Nesov 1990, 1992; Nesov and Panteleyev 1993; Roček and Nesov 1993; Brinkman et al 1994; Currie et al 1994; Archibald et al 1998; Nesov and Panteleeva 1999; Panteleyev 1999; Averianov 2002a; Archibald and Averianov 2005, 2012; Danilov and Parham 2005; Szalay and Sargis 2006; Averianov and Sues 2007, 2012b; Danilov 2007; Feldmann et al 2007; Rezvyi 2007; Skutschas 2009, 2013; Sues and Averianov 2009a, b, 2013; …”

An unusual dinosaur from the Late Cretaceous of Romania and the island rule

“…One of the unresolved issues concerning the Late Cretaceous Hat xeg biota had been its origin: was the Hat xeg region a refugium for survivors of ancient lineages that had been in place for millions of years or did some of the taxa indicate faunal connections with neighboring continents late into the Cretaceous? The phylogenetic relationships of the small hadrosauroids Telmatosaurus and Tethyshadros (from the Maastrichtian Adriatic-Dinaric Island) suggest faunal connections to Asia (12)(13)(14), and the discovery of Baldaur now lends further support to this hypothesis. The recently described basal ceratopsian dinosaur Ajkaceratops from the early Late Cretaceous (Santonian) of Hungary (15) seems to represent yet another paleobiogeographic link between Europe and Asia.…”

Ornithischian dinosaur material from the Kuwajima Formation (Tetori Group: Lower Cretaceous) of Ishikawa Prefecture, Japan

“…The presence of secondary ridges, as well as the presence of mammillae, excludes the teeth from the more deeply nested clade Hadrosauridae (e.g. Norman 2002; Sues and Averianov 2009;McDonald et al 2010;Wu and Godefroit 2012) so that the Shiramine taxon is best regarded as a non-hadrosaurid styracosternan.…”