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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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Absolute frequencies of R2 values from the extensive graphical analyses.A line graph demonstrating the frequencies (y-axis) of R2 values for each respective hypothesis tested in the 120 graphs. The R2 values are ordered from strong support to low support, left to right (x-axis). Morphotype one is represented by a dashed line, morphotype two is represented by a solid line, all specimens of “Pterodactylus” are represented by a dotted line. The highest peaks of the two morphotypes are marked and labelled. The area under the strongest supported hypothesis (morphotype two) is shaded grey for clarity. Likewise, the topologies of the lines are reproduced to the right of the graph.
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pone-0110646-g012: Absolute frequencies of R2 values from the extensive graphical analyses.A line graph demonstrating the frequencies (y-axis) of R2 values for each respective hypothesis tested in the 120 graphs. The R2 values are ordered from strong support to low support, left to right (x-axis). Morphotype one is represented by a dashed line, morphotype two is represented by a solid line, all specimens of “Pterodactylus” are represented by a dotted line. The highest peaks of the two morphotypes are marked and labelled. The area under the strongest supported hypothesis (morphotype two) is shaded grey for clarity. Likewise, the topologies of the lines are reproduced to the right of the graph.

Mentions: The absolute frequencies of R2 values for each of the 120 graphs were plotted on a line graph (Fig. 12) to demonstrate the relative support for each hypothetical morphotype and all specimens (i.e. Pterodactylus antiquus hypodigm sensu Bennett [2]). The line graph demonstrates that both morphotype one (65% R2 values >0.75) and two (100% R2 values >0.75) are strongly supported when compared to the results from all the specimens analysed collectively (54% R2 values >0.75). However, morphotype two is significantly better supported than morphotype one. For morphotype two 96.7% of all R2 values are above 0.9, and all remaining R2 value support is greater than 0.79, compared to morphotype one with only 56.7% of all R2 values above 0.9, and as much as 20% below 0.5. The most striking results are orbit depth vs femur length (Fig. 9) and cervical vertebra five width, where morphotype one has an R2 value less than 0.1, suggesting that hypothetical morphotype one might contain more than one species. This is further supported by the Tukey-Kramer HSD test that shows no statistical significance between morphotype one and the all-inclusive sample, but supports a statistically significant difference in morphotype two with respect to morphotype one and the all-inclusive sample.


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)

Absolute frequencies of R2 values from the extensive graphical analyses.A line graph demonstrating the frequencies (y-axis) of R2 values for each respective hypothesis tested in the 120 graphs. The R2 values are ordered from strong support to low support, left to right (x-axis). Morphotype one is represented by a dashed line, morphotype two is represented by a solid line, all specimens of “Pterodactylus” are represented by a dotted line. The highest peaks of the two morphotypes are marked and labelled. The area under the strongest supported hypothesis (morphotype two) is shaded grey for clarity. Likewise, the topologies of the lines are reproduced to the right of the graph.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0110646-g012: Absolute frequencies of R2 values from the extensive graphical analyses.A line graph demonstrating the frequencies (y-axis) of R2 values for each respective hypothesis tested in the 120 graphs. The R2 values are ordered from strong support to low support, left to right (x-axis). Morphotype one is represented by a dashed line, morphotype two is represented by a solid line, all specimens of “Pterodactylus” are represented by a dotted line. The highest peaks of the two morphotypes are marked and labelled. The area under the strongest supported hypothesis (morphotype two) is shaded grey for clarity. Likewise, the topologies of the lines are reproduced to the right of the graph.
Mentions: The absolute frequencies of R2 values for each of the 120 graphs were plotted on a line graph (Fig. 12) to demonstrate the relative support for each hypothetical morphotype and all specimens (i.e. Pterodactylus antiquus hypodigm sensu Bennett [2]). The line graph demonstrates that both morphotype one (65% R2 values >0.75) and two (100% R2 values >0.75) are strongly supported when compared to the results from all the specimens analysed collectively (54% R2 values >0.75). However, morphotype two is significantly better supported than morphotype one. For morphotype two 96.7% of all R2 values are above 0.9, and all remaining R2 value support is greater than 0.79, compared to morphotype one with only 56.7% of all R2 values above 0.9, and as much as 20% below 0.5. The most striking results are orbit depth vs femur length (Fig. 9) and cervical vertebra five width, where morphotype one has an R2 value less than 0.1, suggesting that hypothetical morphotype one might contain more than one species. This is further supported by the Tukey-Kramer HSD test that shows no statistical significance between morphotype one and the all-inclusive sample, but supports a statistically significant difference in morphotype two with respect to morphotype one and the all-inclusive sample.

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