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Pterodactylus scolopaciceps Meyer, 1860 (Pterosauria, Pterodactyloidea) from the Upper Jurassic of Bavaria, Germany: the problem of cryptic pterosaur taxa in early ontogeny.

Vidovic SU, Martill DM - PLoS ONE (2014)

Bottom Line: P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate.Consequently, the new genus Aerodactylus is erected to accommodate it.A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.

View Article: PubMed Central - PubMed

Affiliation: School of Earth and Environmental sciences, University of Portsmouth, Portsmouth, United Kingdom.

ABSTRACT
The taxonomy of the Late Jurassic pterodactyloid pterosaur Pterodactylus scolopaciceps Meyer, 1860 from the Solnhofen Limestone Formation of Bavaria, Germany is reviewed. Its nomenclatural history is long and complex, having been synonymised with both P. kochi (Wagner, 1837), and P. antiquus (Sömmerring, 1812). The majority of pterosaur species from the Solnhofen Limestone, including P. scolopaciceps are represented by juveniles. Consequently, specimens can appear remarkably similar due to juvenile characteristics detracting from taxonomic differences that are exaggerated in later ontogeny. Previous morphological and morphometric analyses have failed to separate species or even genera due to this problem, and as a result many species have been subsumed into a single taxon. A hypodigm for P. scolopaciceps, comprising of the holotype (BSP AS V 29 a/b) and material Broili referred to the taxon is described. P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate. Consequently, the new genus Aerodactylus is erected to accommodate it. Aerodactylus can be diagnosed on account of a unique suite of characters including jaws containing 16 teeth per-jaw, per-side, which are more sparsely distributed caudally and terminate rostral to the nasoantorbital fenestra; dorsal surface of the skull is subtly depressed rostral of the cranial table; rostrum very elongate (RI = ∼7), terminating in a point; orbits correspondingly low and elongate; elongate cervical vertebrae (approximately three times the length of their width); wing-metacarpal elongate, but still shorter than the ulna and first wing-phalanx; and pteroid approximately 65% of the total length of the ulna, straight and extremely thin (less than one third the width of the ulna). A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.

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Related in: MedlinePlus

Skull depth vs PCRW.A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and Pterodactylus antiquus (open square) in respect to their skull depth and the length of their PCRW. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.
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pone-0110646-g011: Skull depth vs PCRW.A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and Pterodactylus antiquus (open square) in respect to their skull depth and the length of their PCRW. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.

Mentions: Distribution 2 would not necessarily be apparent in the R2 values, but clear differences between morphotypes are apparent on the graphs. An analysis of nasoantorbital fenestra length vs depth (Fig. 10) exhibits a cross-cutting relationship, with R2 values of 0.34 for morphotype one, 0.99 for morphotype two, and 0.77 for all specimens collectively. Despite the intersecting regression lines in the nasoantorbital fenestra length vs depth graph, two specimens of each morphotype lie outside of the other’s 95% confidence ellipse. Pes length vs humeral length demonstrates diverging regression lines, with R2 values of 0.99 for morphotype one, 0.98 for morphotype two, and 0.53 for all specimens collectively. The trend lines for skull depth vs cervical vertebra five length and PCRW both diverge to varying degrees. However, while skull depth vs cervical vertebra five length demonstrates a stronger positive allometry for morphotype two (Fig. 8), the PCRW demonstrates a stronger positive allometry for morphotype one (Fig. 11). In this case morphotype two has a much longer neck in later ontogeny if it represents a valid taxon, while ontogenetically less mature specimens of the two morphotypes are much more similar. Likewise, nasoantorbital fenestra length vs cervical vertebra five length and humeral length demonstrate strong support for each morphotype, but the diverging lines suggest dramatically different proportions would be present in later ontogeny.


Pterodactylus scolopaciceps Meyer, 1860 (Pterosauria, Pterodactyloidea) from the Upper Jurassic of Bavaria, Germany: the problem of cryptic pterosaur taxa in early ontogeny.

Vidovic SU, Martill DM - PLoS ONE (2014)

Skull depth vs PCRW.A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and Pterodactylus antiquus (open square) in respect to their skull depth and the length of their PCRW. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206445&req=5

pone-0110646-g011: Skull depth vs PCRW.A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and Pterodactylus antiquus (open square) in respect to their skull depth and the length of their PCRW. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.
Mentions: Distribution 2 would not necessarily be apparent in the R2 values, but clear differences between morphotypes are apparent on the graphs. An analysis of nasoantorbital fenestra length vs depth (Fig. 10) exhibits a cross-cutting relationship, with R2 values of 0.34 for morphotype one, 0.99 for morphotype two, and 0.77 for all specimens collectively. Despite the intersecting regression lines in the nasoantorbital fenestra length vs depth graph, two specimens of each morphotype lie outside of the other’s 95% confidence ellipse. Pes length vs humeral length demonstrates diverging regression lines, with R2 values of 0.99 for morphotype one, 0.98 for morphotype two, and 0.53 for all specimens collectively. The trend lines for skull depth vs cervical vertebra five length and PCRW both diverge to varying degrees. However, while skull depth vs cervical vertebra five length demonstrates a stronger positive allometry for morphotype two (Fig. 8), the PCRW demonstrates a stronger positive allometry for morphotype one (Fig. 11). In this case morphotype two has a much longer neck in later ontogeny if it represents a valid taxon, while ontogenetically less mature specimens of the two morphotypes are much more similar. Likewise, nasoantorbital fenestra length vs cervical vertebra five length and humeral length demonstrate strong support for each morphotype, but the diverging lines suggest dramatically different proportions would be present in later ontogeny.

Bottom Line: P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate.Consequently, the new genus Aerodactylus is erected to accommodate it.A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.

View Article: PubMed Central - PubMed

Affiliation: School of Earth and Environmental sciences, University of Portsmouth, Portsmouth, United Kingdom.

ABSTRACT
The taxonomy of the Late Jurassic pterodactyloid pterosaur Pterodactylus scolopaciceps Meyer, 1860 from the Solnhofen Limestone Formation of Bavaria, Germany is reviewed. Its nomenclatural history is long and complex, having been synonymised with both P. kochi (Wagner, 1837), and P. antiquus (Sömmerring, 1812). The majority of pterosaur species from the Solnhofen Limestone, including P. scolopaciceps are represented by juveniles. Consequently, specimens can appear remarkably similar due to juvenile characteristics detracting from taxonomic differences that are exaggerated in later ontogeny. Previous morphological and morphometric analyses have failed to separate species or even genera due to this problem, and as a result many species have been subsumed into a single taxon. A hypodigm for P. scolopaciceps, comprising of the holotype (BSP AS V 29 a/b) and material Broili referred to the taxon is described. P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate. Consequently, the new genus Aerodactylus is erected to accommodate it. Aerodactylus can be diagnosed on account of a unique suite of characters including jaws containing 16 teeth per-jaw, per-side, which are more sparsely distributed caudally and terminate rostral to the nasoantorbital fenestra; dorsal surface of the skull is subtly depressed rostral of the cranial table; rostrum very elongate (RI = ∼7), terminating in a point; orbits correspondingly low and elongate; elongate cervical vertebrae (approximately three times the length of their width); wing-metacarpal elongate, but still shorter than the ulna and first wing-phalanx; and pteroid approximately 65% of the total length of the ulna, straight and extremely thin (less than one third the width of the ulna). A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.

Show MeSH
Related in: MedlinePlus