Skull depth <i>vs</i> PCRW.

<p>A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and <i>Pterodactylus antiquus</i> (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.</p

Line drawings of seven skulls belonging to <i>Pterodactylus antiquus</i> (<i>sensu</i> Bennett [2]).

<p>A & B) two opposing reconstructions of the holotype of <i>P. kochi</i> (SMF R 404/BSP AS XIX); C) the holotype of <i>Pterodactylus antiquus</i> (BSP AS I 739); D) a large specimen of “<i>Pterodactylus kochi</i>” (BSP 1883 XVI 1); E) Broili (1938) specimen of <i>Pterodactylus scolopaciceps</i> (BSP 1937 I 18); F) the holotype of <i>Pterodactylus scolopaciceps</i> (BSP AS V 29 a/b); G) a small juvenile specimen of <i>Pterodactylus kochi</i> (NHMUK PV R 3949, OUMNH JZ 1609); H) a small juvenile specimen of <i>Pterodactylus kochi</i> (SMF R 4072). Scale bars = 10 mm.</p

A private specimen of <i>Aerodactylus</i> demonstrating the shoulder girdle morphology.

<p>A) A photograph of a private specimen, which plots onto all graphs on the regression line belonging to morphotype two, thus is identified as <i>Aerodactylus scolopaciceps</i> gen. nov. The area of the photograph illustrates the morphology of the coracoid and humerus. The humerus is more similar to that of <i>Aurorazhdarcho</i>, but the proportions of the wing metacarpal are similar to <i>Aerodactylus scolopaciceps</i> gen. nov. B) Interpretive line diagram: co, coracoid; cv, cervical vertebra; hu, humerus; pt, pteroid; ra, radius; sc, scapula; ul, ulna; wph1, wing-phalanx one; wph2, wing-phalanx two. Scale bar = 10 mm.</p

Orbit depth <i>vs</i> femur length.

<p>A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and <i>Pterodactylus antiquus</i> (Open square) in respect to their orbit depth and femur length. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.</p

A graph of Solnhofen pterodactyloids compiled from data available in Wellnhofer [15].

<p>Skull length plotted along the x-axis, wing metacarpal length plotted along the y-axis. Despite clear morphological differences a crowded data set has resulted in all specimens appearing similar. A similar situation is observed when all other elements plotted against skull length. <i>P. antiquus</i> filled circles, <i>P. kochi</i> open squares, <i>Ctenochasma</i> open circles. R² values: all specimens = 0.931; <i>P. antiquus</i> specimens = 0.998; <i>P. kochi</i> specimens = 0.959; <i>Ctenochasma gracile</i> + <i>P. elegans</i> ( = <i>Ctenochasma elegans</i>) = 0.942. Dashed lines are regression lines for each respective taxon, the solid line is the regression line for all specimens.</p

A single most parsimonious tree of the Pterodactyloidea recovered using a TNT “new technology search”.

<p>Named nodes: 1 = Monofenestrata Lü et al. 2010 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-L1" target="_blank">[30]</a>; 2 = Pterodactyloidea Plieninger 1901 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Plieninger1" target="_blank">[31]</a>; 3 = Ctenochasmatidae Nopcsa 1928 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Nopcsa1" target="_blank">[32]</a>; 4 = Lophocratia Unwin 2003 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Unwin1" target="_blank">[33]</a>; 5 = Aurorazhdarchidae <i>fam. nov.</i>; 6 = Ornithocheiroidea Seeley 1891 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Seeley1" target="_blank">[34]</a>; 7 = Istiodactylidae Howse et al. 2001 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Howse1" target="_blank">[35]</a>; 8 = Pteranodontia Marsh 1876 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Marsh1" target="_blank">[36]</a>; 9 = Anhangueridae Campos and Kellner 1985 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Campos1" target="_blank">[37]</a>; 10 = Tapejaroidea Kellner 1996 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Kellner2" target="_blank">[38]</a>; 11 = Azhdarchoidea Nesov 1984 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Nesov1" target="_blank">[39]</a>; 12 = Azhdarchidae Nesov 1984 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Nesov1" target="_blank">[39]</a>; 13 = Tapejaridae Kellner 1989 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110646#pone.0110646-Kellner3" target="_blank">[40]</a>.</p

Skull length <i>vs</i> skull depth.

<p>A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and <i>Pterodactylus antiquus</i> (Open square) in respect to their skull length and skull depth. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.</p

A demonstration of <i>i = tan⁻¹a/b</i> rescaling on triangles with opposing dimensions.

<p>The plots at the top demonstrate the data distribution of the triangles illustrated below, where Q = raw quotient value of triangle length/depth, and <i>i</i> = rescaled quotient values of triangle length/depth. The colours of triangles Ai – Ci, Aii – Cii and D are replicated in the diamonds in the plots for clarity. The depths (di) of Ai – Ci are equal to the lengths (also di) of Aii – Cii respectively. Likewise, the lengths (dii) of Ai – Ci are equal to the depths (also dii) of Aii – Cii. D is an equilateral triangle, and on the plots it demonstrates the transition between tall and long forms. The diagram demonstrates that triangles with the same range of variation between both shallow-long forms and deep-short forms will only exhibit the true range of variation once the <i>i = tan⁻¹a/b</i> rescaling has been applied.</p

Cladograms based on the results of a cladistic analysis by Howse [43].

<p>Pterodactylus elegans = Ctenochasma elegans; Pterodactylus micronyx = Aurorazhdarcho micronyx; Gallodactylus = Cycnorhamphus; Pterodactylus longicollum = Ardeadactylus longicollum; Doratorhynchus = Pterodactyloidea incertae sedis. (?azhdarchid?); Titanopteryx = Arambourgiana; Greensand long cervical vertebrae = no specimen number or reference given.</p

Skull depth <i>vs</i> cervical vertebra 5 length.

<p>A graph demonstrating the spread of data between morphotype one (open circles), morphotype two (filled circles) and <i>Pterodactylus antiquus</i> (Open square) in respect to their skull depth and cervical vertebra 5 length. Solid black lines = regression lines for respective morphotypes; dashed grey lines = 95% confidence limits.</p