Pterodactylus daviesii, Owen, 1874

Rodrigues, Taissa & Kellner, Alexander Wilhelm Armin, 2013, Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England, ZooKeys 308, pp. 1-112 : 35-36

' Pterodactylus ' daviesii Owen, 1874 Fig. 13A-D

Pterodactylus daviesii Owen: Owen 1874: p. 2, pl. I, fig. 5-6

Lonchodectes daviesii (Owen): Hooley 1914: p. 538

Ornithocheirus daviesii (Owen): Arthaber 1922: p. 16

Ornithochirus [sic] daviesi [sic] (Owen): Lydekker 1888: p. 23

Ornithocheirus daviesi [sic] (Owen): Wellnhofer 1978: p. 56, fig. 28

Lonchodectes platystomus (Seeley): Unwin 2001: fig. 12C

Holotype.

NHMUK PV 43074, partial mandibular symphysis ( Fig. 13A-D ).

Type locality.

Folkestone, Kent, England.

Type horizon.

Gault Clay Formation (Albian).

Diagnosis.

Pterodactyloid pterosaur with the following combination of characters that distinguishes it from other members of the clade (autapomorphies are marked with an asterisk): anterior expansion absent; mandibular crest absent; mandibular groove about 2.5 cm wide; mandibular groove with elevated margins; mandibular groove extends until the second pair of alveoli; alveoli of the anterior portion of the mandible without significant variation in size; alveoli equally spaced; first pair of teeth face anterodorsally; transverse section ‘V-shaped’; approximately 4 alveoli per 3 cm of jaw margin*.

Description.

'Pterodactylus' daviesii is known from a partial mandibular symphysis from the Gault Clay Formation. In his description, Owen (1874) stressed the presence of a mandibular sulcus and that the first pair of alveoli is less elliptical than the remaining ones and directed forwards and upwards. 'Pterodactylus' daviesii presents a unique mosaic of seemingly plesiomorphic features among pterodactyloids. It lacks an anterior expansion, a crest, or any other distinctive dental feature, which would permit referral to a known genus. Instead, it is the combination of these characters that makes this species distinct from all known pterodactyloid genera.

It shares with Lonchodraconidae the presence of alveoli of the anterior portion of the mandible without significant variation in size, but can be confidently excluded from this clade because its alveoli are slightly larger and are not located on elevated alveolar margins. Although the dentary sulcus is relatively wide, it is narrower than in Lonchodraco machaerorhynchus . 'Pterodactylus' daviesii is also distinct from Lonchodraco giganteus . In the latter, the mandible is very wide, with divergent margins, and rounded anteriorly. Although not comparable to Ornithocheirus simus , it is unlikely that it represents this much larger pterosaur.

Remarks.

Unwin (2001) did not cite ' Pterodactylus' daviesii in the text of his review, but illustrated the holotype, referring to it as Lonchodectes [= 'Ornithocheirus' ] platystomus, and indicated that it bears a crest. We disagree that NHMUK PV 43074 represents a crested pterosaur; the ventral margin of the dentary is sharp but there is no evidence for a crest. Furthermore, 'Pterodactylus' daviesii is not directly comparable to 'Ornithocheirus' platystomus because the latter is known only from an upper jaw.

'Pterodactylus' daviesii thus possibly represents a distinct taxon from the Gault Clay Formation. However, we refrain from naming it until more complete material becomes available and refer it using its original designation in single quotation marks.

Figures

Figure 13. A-D ' Pterodactylus' daviesii, holotype NHMUK PV 43074 (Albian, Gault Clay Formation), anterior part of the mandibular symphysis. A right lateral view B respective line drawing C dorsal view D respective line drawing. E-H ' Ornithocheirus' denticulatus, holotype? CAMSM B 54794 (Albian, Cambridge Greensand), anterior part of the rostrum E ventral view F respective line drawing G right lateral view H respective line drawing. Abbreviations: m - maxillae, pm - premaxillae, prid - palatal ridge, sul - sulcus. Arrows and numbers indicate alveoli or teeth and their respective position. Scale bar = 10 mm. E and G from Seeley 1870. Photos A and C courtesy of The Natural History Museum.