Tuesday, September 26, 2017

[Paleontology • 2017] Burianosaurus augustai • A Basal Ornithopod Dinosaur from the Cenomanian of the Czech Republic

 Burianosaurus augustai 
 Madzia, Boyd & Mazuch, 2017

During their long evolutionary history, neornithischian dinosaurs diverged into several clades with distinctive adaptations. However, the early evolution within Neornithischia and the resolution of the phylogenetic relationships of taxa situated near the base of the clade remain problematic. This is especially true for those taxa traditionally placed at the base of Ornithopoda, either as ‘hypsilophodontids’ or at the base of the diverse clade Iguanodontia. Recent studies are improving our understanding of the anatomy and relationships of these taxa, with discoveries of several new non-ankylopollexian ornithopods from South America and Europe providing key insights into early ornithopod evolution and palaeobiogeography. Here, we describe a new basal ornithopod, Burianosaurus augustai gen. et sp. nov., based on a well-preserved femur from the upper Cenomanian strata (Korycany Beds of the Peruc-Korycany Formation) of the Czech Republic. The new taxon is diagnosed by a unique suite of characters and represents the only occurrence of a Cenomanian non-avian dinosaur in Central Europe north of the Alpine Tethyan areas. Histological examination of the type specimen reveals the presence of a loosely packed Haversian system which suggests relatively mature bone from a possible young adult. Phylogenetic analyses of two different data sets, selected to test the placement of B. augustai in various parts of the neornithischian tree, reconstruct B. augustai as a basal ornithopod, firmly nested outside Ankylopollexia. These results also support a diverse Elasmaria as a basal clade within Ornithopoda and reconstruct Hypsilophodon outside Ornithopoda as the sister taxon to Cerapoda. However, the relationships of ‘hypsilophodontids’ within Neornithischia remain contentious.

Keywords: Ornithopoda, Dinosauria, phylogeny, Cenomanian, Czech Republic

[2017] Figure 1. The holotype left femur (NMP Ob 203) of Burianosaurus augustai gen. et sp. nov.

[2005] Fig. 3. Left femur of cf. Iguanodontidae gen. et sp. indet. (Ornithischia, Ornithopoda), IGP MZHLZ/2003/1, in posterior (A), lateral (B), medial (C), ante− rior (D), and distal (F) views, with transverse cross−section through the femoral shaft (E).
(Fejfar, Košťák, Kvacek, et al. 2005) app.pan.pl/article/item/app50-295.html

Systematic palaeontology
Dinosauria Owen, 1842
Ornithischia Seeley, 1887
Neornithischia Cooper, 1985
Ornithopoda Marsh, 1881
Genus Burianosaurus gen. nov.
2005 cf. Iguanodontidae gen. et sp. indet.
Fejfar, Košťák, Kvacek, Mazuch, & Moucka: 297, fig. 3.

Age. Late Cenomanian, early Late Cretaceous.

Derivation of name. The name Burianosaurus is derived from the surname of the Czech palaeoartist Zdenek Burian (1905–1981) who greatly influenced the perception of dinosaurs during most of the twentieth century, and saῦro & (sauros), the Greek word for ‘reptile’ or ‘lizard’.

 Burianosaurus augustai sp. nov.

Holotype. NMP Ob 203, a well-preserved, nearly complete left femur.

Derivation of name. The name augustai refers to the prominent Czech palaeontologist and prolific science populariser Josef Augusta (1903–1968).

 Burianosaurus augustai sp. nov.
 Illustration: Edyta Felcyn

Only two definitive non-avian dinosaur specimens have been described from the Czech Republic to date: NMP Ob 203, a well-preserved left femur from the upper Cenomanian (Upper Cretaceous), introduced by Fejfar et al. (2005) under temporary catalogue number IGP MZHLZ/ 2003/1, and IGS-MJ-0001 (currently DGSMU Pa 222), an isolated tetanurine tooth crown from the Oxfordian (Upper Jurassic) published by Madzia (2014).

A re-evaluation of the phylogenetic relationships of NMP Ob 203 demonstrates that this specimen actually represents a non-ankylopollexian ornithopod, here named Burianosaurus augustai gen. et sp. nov. Analysis of a modified version of the Boyd (2015) basal neornithischian data set reconstructs Baugustai as a basal member of Ornithopoda, positioned more rootward than the rhabdodontomorphs but more derived than the Gondwanan elasmarians. The new taxon can be distinguished from all other ornithopods by a unique suite of morphological characters present in the femur. From a palaeobiogeographical perspective, B. augustai represents the only occurrence of a non-avian dinosaur from the Cenomanian of Central Europe north of the Alpine Tethyan areas (Fejfar et al. 2005; Csiki-Sava et al. 2015). This discovery adds to the growing body of work demonstrating the importance of the European fossil record for studying the evolution of non-ankylopollexian ornithopods (e.g. Ősi et al. 2012; Ruiz-Omeñaca et al. 2012).

Daniel Madzia, Clint A. Boyd and Martin Mazuch. 2017. A Basal Ornithopod Dinosaur from the Cenomanian of the Czech Republic. Journal of Systematic Palaeontology. DOI:  10.1080/14772019.2017.1371258

Reconstruction of the possible form of the first "Czech" dinosaur, which was named Burianosaurus augustai. Only the femur is preserved from the specimen, so based on data on related species.... Illustration: Edyta Felcyn,
První český dinosaurus se změnil: byl primitivnější a nebyl zakrslý  technet.idnes.cz/cesko-kosti-dinosaurus-burianosaurus-augustai-f57-/veda.aspx via @iDNEScz

We describe the first dinosaur skeletal remains found in the Czech Republic, consisting of one complete femur and indeterminable bone fragments. They were recovered from the upper Cenomanian near-shore marine sediments deposited on the slopes of an ancient archipelago, several kilometres north of the larger Rhenish-Bohemian Island that was situated in what is now the middle of Europe. Sediments yielding dinosaur remains are of late Cenomanian age, Inoceramus pictus-I. pictus bohemicus inoceramid zone of the local lithostratigraphic unit, the Peruc-Korycany Formation. These are the first uncontested dinosaurian fossils reported from this formation and also the first Cenomanian dinosaur record in Central Europe. They document a small ornithopod belonging to an iguanodontid species comparable with similar Late Cretaceous European forms. The herbivorous dinosaur lived among a vegetation transitional between salt marsh flora, with abundant halophytic conifer Frenelopsis alata; and an alluvial plain assemblage dominated by lauroid angiosperms.
Key words: Dinosauria, Iguanodontidae, palaeoenvironment, vegetation, Cenomanian, Bohemian Cretaceous Basin, Czech Republic, Europe.

Oldřich Fejfar, Martin Košťák, Jiří Kvaček, Martin Mazuch, and Michal Moučka. 2005. First Cenomanian dinosaur from Central Europe (Czech Republic). Acta Palaeontologica Polonica. 50(2); 295-300.  app.pan.pl/article/item/app50-295.html

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