Sunday, October 6, 2019

[Paleontology • 2019] Ferrodraco lentoni • A New Ornithocheirid Pterosaur from the Winton Formation (Cenomanian–lower Turonian) of Queensland, Australia

Ferrodraco lentoni
Pentland, Poropat, Tischler, Sloan, Elliott, et al., 2019

Illustration by Travis R. Tischler.

The Australian pterosaur record is poor by world standards, comprising fewer than 20 fragmentary specimens. Herein, we describe the new genus and species Ferrodraco lentoni gen. et sp. nov., based on the most complete pterosaur specimen ever found in Australia, and the first reported from the Winton Formation (Cenomanian–lower Turonian). The presence of premaxillary and mandibular crests, and spike-shaped teeth with subcircular bases, enable Ferrodraco to be referred to Anhangueria. Ferrodraco can be distinguished from all other anhanguerian pterosaurs based on two dental characters: the first premaxillary and mandibular tooth pairs are small; and the fourth–seventh tooth pairs are smaller than the third and eighth ones. Ferrodraco was included in a phylogenetic analysis of Pterosauria and resolved as the sister taxon to Mythunga camara (upper Albian Toolebuc Formation, Australia), with that clade occupying the most derived position within Ornithocheiridae. Ornithocheirus simus (Albian Cambridge Greensand, England), Coloborhynchus clavirostris (Valanginian Hastings Sands, England), and Tropeognathus mesembrinus (upper Aptian–lower Albian Romualdo Formation, Brazil) were resolved as successive sister taxa, which suggests that ornithocheirids were cosmopolitan during the Albian–Cenomanian. Furthermore, the stratigraphic age of Ferrodraco lentoni (Cenomanian–lower Turonian) implies that anhanguerians might have survived later in Australia than elsewhere.

Systematic palaeontology
Pterosauria Kaup, 1834
Pterodactyloidea Plieninger, 1901
Ornithocheiroidea Seeley, 1891 sensu Kellner, 2003

Anhangueria Rodrigues and Kellner, 2013
Ornithocheirae Seeley, 1870
Ornithocheiridae Seeley, 1870
Ornithocheirinae Andres, Clark and Xu, 2014
Figure 3: Ferrodraco lentoni gen. et sp. nov. holotype skull and mandible AODF 876.
(A) dorsal view; (B) anterior view; (C) left lateral view; (D) ventral view; (E) right lateral view; (F) schematic of left lateral view; and (G) schematic of right lateral view.
Abbreviations: d, dentary; dcr, (preserved base of) dentary crest; ll#, lower left (alveolus number); lr#, lower right (alveolus number); man, mandibular ramus; ms, mandibular symphysis; pmcr, premaxillary crest; pmx-mx, premaxilla–maxilla; ul#, upper left (alveolus number); ur#, upper right (alveolus number). Scale bar = 50 mm.

Figure 2: Ferrodraco lentoni gen. et sp. nov. holotype specimen AODF 876.
All preserved elements were photographed and scaled to the same size, then articulated where possible. These were then used as the basis for the scaling of the skeletal reconstruction, the missing parts of which were based on the skeletal reconstruction of Tropeognathus mesembrinus by Witton. Scale bar = 50 mm.

Ferrodraco lentoni gen. et sp. nov.

Holotype: Australian Age of Dinosaurs Fossil (AODF, Winton, Queensland, Australia) 876 (‘Butch’): anterior portion of skull comprising partial premaxillae, maxillae and dentaries (including premaxillary and mandibular crests and the mandibular symphysis); partial left frontal; left mandibular articular region comprising the surangular, angular and articular; five partial cervical vertebrae; partial right scapulocoracoid; partial left ulna; partial left radius; left proximal and distal carpals; left metacarpal IV; proximal end of right metacarpal IV; fragmentary left non-wing manual phalanges; partial left first wing phalanx (IV-1); and associated fragments. Several elements, including the skull and mandible and many of the appendicular elements (based on key-fits between adherent matrix on anatomically adjacent elements) were clearly articulated post-fossilisation; however, erosion and soil rotation led to fragmentation of the specimen prior to its excavation.

Type horizon and locality: Winton Formation (Cenomanian–lower Turonian); Australian Age of Dinosaurs Locality (AODL, Winton, Queensland, Australia) 245 (the ‘Pterosaur Site’), Belmont Station, Winton, Queensland, Australia (Fig. 1).
Diagnosis: Anhanguerian pterodactyloid diagnosed by the following autapomorphies: (1) first tooth pair of the premaxilla and mandible smaller than other anterior teeth; (2) fourth up to seventh teeth smaller than third and eighth.

Figure 1: Location of the Ferrodraco lentoni gen. et sp. nov. type locality (AODL 245).
(a) Map of Australia showing the location of Queensland. (b) Map of Queensland showing the distribution of Winton Formation outcrop. (c) Map of the Winton area showing Winton Formation outcrop, the location of Belmont Station, and museums in the region. 

Etymology: From the Latin ferrum (iron), in reference to the ironstone preservation of the holotype specimen, and the Latin draco (dragon). The species name honours former Winton Shire mayor Graham Thomas ‘Butch’ Lenton, in recognition of his years of service to the Winton community and support to the Australian Age of Dinosaurs Natural History Museum.
Figure 7: Time-calibrated phylogenetic trees of Ornithocheiroidea (Pterosauria: Pterodactyloidea), with some non-anhanguerian nodes collapsed for simplicity. The box next to each taxon demarcates its temporal range (including stratigraphic uncertainty), whereas the colour of each box reflects the palaeoenvironmental setting from which the taxon derives (yellow = terrestrial; blue = marine).
 (A) Tree based on the matrix of Andres et al. 2014, with Ferrodraco lentoni gen. et sp. nov. and Mythunga camara included; (B) Tree based on the matrix of Lü et al. 2018, with Ferrodraco lentoni gen. et sp. nov. included.

Figure 8: Life restoration of Ferrodraco lentoni gen. et sp. nov.  as an ornithocheirid pterosaur.
Illustration by Travis R. Tischler.

Figure 6: Australian pterosaur holotype cranial material.
(A) Ferrodraco lentoni gen. et sp. nov.  holotype skull and mandible (AODF 876);
(B) Mythunga camara Molnar and Thulborn, 2007 holotype skull and mandible (QM F18896);
and (C) Aussiedraco molnari Kellner, Rodrigues and Costa, 2011 holotype mandible (QM F10613).
Scale bar = 20 mm.

Adele H. Pentland, Stephen F. Poropat, Travis R. Tischler, Trish Sloan, Robert A. Elliott, Harry A. Elliott, Judy A. Elliott and David A. Elliott. 2019. Ferrodraco lentoni gen. et sp. nov., A New Ornithocheirid Pterosaur from the Winton Formation (Cenomanian–lower Turonian) of Queensland, Australia. Scientific Reports. 9: 13454. DOI: 10.1038/s41598-019-49789-4