''Ferrodraco'' ("Iron Dragon" after the ironstone the fossil was found in) is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of anhanguerid pterosaur known from the Late Cretaceous Winton Formation of Queensland,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, containing the single species ''F. lentoni''. The species was named after the former mayor of Winton, Graham Thomas ‘Butch’ Lenton. It is the most complete pterosaur fossil from Australia, being known from the holotype specimen AODF 876, consisting primarily of the anterior portion of the skull and dentary, cervical vertebral centra and a partial wing. Its wingspan was estimated to be about . ''Ferrodraco'' was found to have been within the subfamily

Ornithocheirinae Ornithocheiridae (or ornithocheirids, meaning "bird hands") is a group of pterosaurs within the suborder Pterodactyloidea. These pterosaurs were among the last to possess teeth. Members that belong to this group lived from the Early Cretaceous, ...

, as sister taxon to '' Mythunga''. A recent study also recovered ''Ferrodraco'' as sister taxon to ''Mythunga'', but both placed within the family Anhangueridae, more specifically within the subfamily

Tropeognathinae Anhangueridae is a group of pterosaurs within the suborder Pterodactyloidea. They were among the last pterosaurs to possess teeth. A recent study discussing the group considered the Anhangueridae to be typified by a premaxillary crest and a later ...

. ''Ferrodraco'' is also the latest surviving member of Anhangueria.

Discovery and naming

Holotypes of Ferrodraco, Mythunga and Aussiedraco

The holotype specimen was initially discovered in April 2017 when cattle farmer Robert A. Elliott was spraying herbicide near Belmont Station. It was excavated by a team led by Adele H. Pentland. Nicknamed 'Butch', it was further prepared by volunteer Ali Calvey. In 2019, the type species ''Ferrodraco lentoni'' was named and described by Adele H. Pentland, Stephen Francis Poropat, Travis R. Tischler, Trish Sloan, Robert A. Elliott, Harry A. Elliott, Judy A. Elliott and David A. Elliott. It was subsequently X-ray CT scanned at high-resolution using the Imaging and Medical Beamline at the Australian Synchrotron and

osteology Osteology () is the scientific study of bones, practised by osteologists. A subdiscipline of anatomy, anthropology, and paleontology, osteology is the detailed study of the structure of bones, skeletal elements, teeth, microbone morphology, funct ...

described in detail. The generic name is derived from the Latin ''ferrum'', "iron", and ''draco'', "dragon", in reference to the fact that the skeleton was found in ironstone. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honors the late mayor of Winton Shire, Graham Thomas ‘Butch’ Lenton, for his work for the local community and his support for the Australian Age of Dinosaurs. He died in 2017. The holotype, AODF 876, was found in a layer of the Winton Formation dating from the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

- lower Turonian, about ninety-six million years old. It consists of a partial skeleton with skull and lower jaws. It contains the front part of the head with the premaxillae, the maxillae and the dentaries; the left frontal bone, the rear part of the left lower jaw; forty single teeth; five neck vertebrae; the right shoulder joint; the left ulna; the left radius; the proximal and distal left wrist bones; two fourth metacarpals; phalanges from the first to third fingers of the left hand; and the first phalanx of the fourth finger. It represents a fully-grown but not yet mature animal. The skeleton has largely been preserved three-dimensionally due to the ironstone, but some bones however, have been crushed. It was probably fossilized in articulation but got some time prior to the discovery dispersed by erosion and cattle. ''Ferrodraco'' is the only pterosaur fossil known from the Winton Formation, and is the most complete pterosaur ever found in Australia, a continent where such finds are rare.

Description

Size and distinguishing traits

The wingspan of ''Ferrodraco'' was estimated at . The describing authors indicated two autapomorphies (distinguishing traits) that ''Ferrodraco'' had. The first tooth pair in both the premaxillae of the snout and in the front lower jaws is smaller than the other front teeth. The fourth to seventh tooth pairs are smaller than the third and eight pair. Additionally, a unique combination is present of traits that in themselves are not unique. The front edge of the premaxilla is flattened and triangular. The first tooth pair in the premaxillae is directed vertically and is slightly set-off to above from the jawline. The front parts of the upper and lower jaws are not expanded sideways. The rear teeth are directed vertically, gradually declining in size. The tooth sockets are swollen relative to the outer wall of the jaw bones. The snout bears a premaxillary crest, the front edge of which continues the line of the snout tip, steeply rising under an angle of 60 degrees, and ending in a rounded crest top.

Skeleton

The length of the skull has been estimated to be about . The snout bears a relatively high crest, and it probably had a triangular profile in side view; the rear edge has not been preserved. The crest is very thin transversely however, only up to thick. It is hollow inside, the smooth bone walls being connected by small struts. The crest has a base length of and a height of . The symphysis of the lower jaws, their front fused area, probably extended to below in a second crest. There is an estimated total of twelve teeth in the upper jaw and thirteen teeth in the lower jaw for a total of fifty in the head as a whole. The teeth are formed as conical spikes with an oval cross-section, transversely flattened. The swollen tooth sockets cause an undulating profile of the jawlines in top view.

Classification

''Ferrodraco'' was the youngest known member of the clade Anhangueria, and proves that the clade did not become extinct during the Late Cretaceous. In 2010 however, an ornithocheirid jaw fragment that includes two teeth (specimen WAM 68.5.11) had been reported from Australia, the same place where ''Ferrodraco'' was found, and this specimen was unearthed in the

Molecap Greensand The Molecap Greensand is a Late Cretaceous geologic formation, located in the state of Western Australia in Australia. A proximal pedal phalanx from an indeterminate theropod has been recovered from the formation, alongside a jaw fragment of a ...

, layers that possibly have an even younger age than ''Ferrodraco''.Kear, B.P., Deacon, G.L. & Siverson, M. 2010. "Remains of a Late Cretaceous pterosaur from the Molecap Greensand of Western Australia". ''Alcheringa'' 34: 273–279 The 2019 study of ''Ferrodraco'' made by Pentland ''et al.'' contained the results of two phylogenetic analyses, trying to determine the position of ''Ferrodraco'' in the evolutionary tree. The first analysis found ''Ferrodraco'' within the clade Ornithocheirae, more precisely within the subfamily

as the sister species of '' Mythunga'', another Australian pterosaur from somewhat older layers. The second analysis placed ''Ferrodraco'' as a basal member of the Anhangueria, and sister taxon to the polytomy that comprises '' Anhanguera'', '' Coloborhynchus'' and '' Ornithocheirus''. A more recent study made in 2020 by Borja Holgado and Rodrigo Pêgas placed ''Ferrodraco'' within the family Anhangueridae, more specifically within the subfamily

, although still the sister taxon to ''Mythunga''. In 2022, Pentland et al. published a detailed description of ''Ferrodraco'' (particularly the post-cranial skeleton) and a renewed phylogenetic appraisal that unequivocally demonstrated that it belongs in the family Anhangueridae as proposed by Holgado and Pêgas. This study suggested that the precise position of ''Ferrodraco'' and ''Mythunga'' within Anhangueridae still remains uncertain, and that the diversity of Australian pterosaur fauna has been greatly underestimated. Topology 1: First analysis by Pentland ''et al.'' (2019). Topology 2: Holgado & Pêgas (2020).

References