Friday, July 28, 2017

[Paleontology • 2017] The Taxonomy and Phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus (Wagner, 1851)

Altmuehlopterus Vidovic & Martill, 2017
Altmuehlopterus rhamphastinus  (Wagner, 1851)

Fig. 2. ‘Germanodactylus rhamphastinus’ – photographs and interpretative drawings of the slabs (a) BSP AS I 745 b and (b) BSP AS I 745 a. Abbreviations: pc, premaxillary crest; st, sternum.

The Solnhofen pterosaurs Pterodactylus antiquus, Aerodactylus scolopaciceps, Diopecephalus kochi, Germanodactylus cristatus and Germanodactylus rhamphastinus all have complicated taxonomic histories. Species originally placed in the genus Pterodactylus, such as Aerodactylus scolopaciceps, Ardeadactylus longicollum, Cycnorhamphus suevicus and Germanodactylus cristatus possess apomorphies not observed in the type species of Pterodactylus, and consequently have been placed in new genera. The affinities of another Solnhofen pterosaur previously placed in Pterodactylus, Diopecephalus kochi, are less clear. It has been proposed that D. kochi is a juvenile specimen of Pterodactylus antiquus, or perhaps ‘Germanodactylus rhamphastinus’ specimens are mature examples of D. kochi. Furthermore, studies have suggested that ‘Germanodactylus rhamphastinus’ is not congeneric with the type species of Germanodactylus. Geometric morphometric analysis of prepubes and a cladistic analysis of the Pterosauria elucidate plesiomorphic and apomorphic conditions for basal Jurassic pterodactyloids. Germanodactylus is found to be a monotypic genus and Pterodactylus, Diopecephalus, and ‘G. rhamphastinus’ are found as distinct taxa belonging in individual genera, diagnosable using a combination of characters. Thus, Diopecephalus kochi is not demonstrated to be congeneric with Germanodactylus or Pterodactylus and is maintained as a valid taxon. ‘G. rhamphastinus’ is readily distinguishable from other Solnhofen pterosaur taxa, and a new genus is erected for its reception.


Altmuehlopterus gen. nov.

Derivation of name.Altmuehl’ refers to the Altmühl river that flows through Solnhofen (close to Mörnsheim), Eichstätt and joins the river Danube at Kelheim. ‘Pterus’ is a common suffix in pterosaur names referring to the wing. This name is presented as an alternative to the geographically significant name Daitingopterus (Maisch et al., 2004) which is a nomen nudum. 

Type species: Altmuehlopterus rhamphastinus (Wagner, 1851) 

Fig. 3. Germanodactylus cristatus – (a) a photograph of most of the skeleton on the slab and (b) a line drawing of the skull of the holotype BSP 1892 IV 1.

Fig. 10. Cranial characters and prepubes of Franconia laminated limestone pterosaurs plotted onto a pruned tree. The tree is plotted against the ‘fine scale’ dating criteria of the Franconia laminated limestones (Schweigert 2007).

Steven U. Vidovic and David M. Martill. 2017. The Taxonomy and Phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus (Wagner, 1851). Geological Society, London. Special Publications. (2017); SP455.12. DOI: 10.1144/SP455.12

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