Camposipterus (?) sedgwickii (Owen, 1859) Rodrigues & Kellner, 2013

Rodrigues, Taissa & Kellner, Alexander Wilhelm Armin, 2013, Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England, ZooKeys 308, pp. 1-112 : 27-29

Camposipterus (?) sedgwickii (Owen, 1859) comb. n. Fig. 10A-D

Pterodactylus sedgwickii Owen: Owen 1859: p. 2, pl. I, fig. 1

"Ptenodactylus" sedgwicki [sic] (Owen): Seeley 1869: p. xvi [disclaimed]

Ornithocheirus sedgwicki [sic] (Owen): Seeley 1870: p. 112

Coloborhynchus sedgwickii (Owen): Owen 1874: p. 6

Ornithochirus [sic] sedgwicki [sic] (Owen): Lydekker 1888: p. 15

Ornithocheirus sedgwicki [sic] (Owen): Hooley 1914: p. 535

Ornithocheirus sedgwicki [sic] (Owen): Arthaber 1922: p. 17

Ornithocheirus sedgwicki [sic] (Owen): Wellnhofer 1978: p. 58, fig. 28

Coloborhynchus sedgwickii (Owen): Unwin 2001: p. 194, fig. 9, table 1

"Ornithocheirus" sedgwickii (Owen): Rodrigues and Kellner 2008: p. 226, fig. 4.2, 4.4

Holotype.

CAMSM B54422, anterior part of the rostrum ( Fig. 10A-D ).

Type locality.

Cambridge, Cambridgeshire, England.

Type horizon.

Cambridge Greensand (Cenomanian; fossils Albian in age).

Diagnosis.

Pterodactyloid pterosaur with the following combination of characters that distinguishes it from other members of the clade (autapomorphies are marked with an asterisk): tall rostrum; anterior expansion of the rostrum ends abruptly behind the third pair of alveoli*; palatal ridge extending posteriorly to the level of the third pair of alveoli; third pair of alveoli much larger than fourth*.

Description.

Owen (1859) described Pterodactylus sedgwickii based on an upper jaw, CAMSM B54422. He pointed out the presence of the first pair of alveoli at the anterior margin of the rostrum, facing forward; an anterior expansion of the rostrum, where the large second and third pairs of alveoli are located; alveoli four to six approximately same size; spacing between alveoli smaller than their diameter; and obtuse tip of the rostrum.

The third alveoli have different sizes on the left and right sides; this could be explained on taphonomic grounds (e.g., Kellner 2010). On the left side, the bone surrounding the alveolus seems to have been forced outwards, perhaps by phosphate deposition ( Seeley 1870). On the other hand, the absence of the fifth alveolus on the left side, as noted by Owen (1859), is a possibly pathological feature seen in other pterosaurs, such as in the holotype of Anhanguera robustus (BSP 1987 I 47) and in a specimen referred to Anhanguera blittersdorffi (Pz-DBAV-UERJ 40).

It is noteworthy that the drawing of CAMSM B54422 was reversed in Owen (1859) and in Wellnhofer (1978) and Unwin (2001), which present illustrations based on Owen’s. Also, there is a breakage and a discontinuity between the anterior, round part of the rostrum and the more posteriorly located dorsal margin, which is not figured by the aforementioned authors.

Owen (1859) referred a lower jaw, CAMSM B54421, to the same species, partially based on a similar alveolar density as in the holotype. CAMSM B54421 is very fragmentary and does not have the tip of the mandible preserved. Furthermore, these two specimens do not fit together, with the upper jaw much broader than the lower one. There is no evidence to support placement of CAMSM B54421 in Camposipterus(?) sedgwickii , and we here restrict the species to its type material.

Remarks.

Hooley (1914) and Wellnhofer (1978) placed Camposipterus(?) sedgwickii in Ornithocheirus . It differs from this genus in the absence of a tall rostrum, the first pair of teeth facing ventrally, and other characters (see above). Owen (1874) and Unwin (2001) referred it to Coloborhynchus . Rodrigues and Kellner (2008) excluded Camposipterus(?) sedgwickii from Coloborhynchus , as it differs from Coloborhynchus clavirostris in that the anterior end of the rostrum is round rather than flat and the spacing between the first and second pairs of alveoli is larger in Coloborhynchus clavirostris . Camposipterus(?) sedgwickii shows none of the autapomorphies listed for Coloborhynchus clavirostris . Therefore, we tentatively place this species in the genus Camposipterus . Camposipterus nasutus and Camposipterus(?) sedgwickii share the presence of an expansion of the rostrum, absence of a premaxillary crest, and round rostrum in lateral view. They differ in the different height of the tip of the rostrum, which is taller than wide in Camposipterus(?) sedgwickii , the extension of the palatal ridge, and the size of the expansion, which is larger in Camposipterus(?) sedgwickii than in Camposipterus nasutus .

Figures

Figure 10. A-D Camposipterus (?) sedgwickii comb. n., holotype CAMSM B 54422 (Albian, Cambridge Greensand), anterior part of the rostrum. A right lateral B respective line drawing C ventral view D respective line drawing. E-H Camposipterus (?) colorhinus comb. n., syntype CAMSM B 54431 (Albian, Cambridge Greensand), anterior part of the rostrum E left lateral view F respective line drawing G ventral view H respective line drawing. Abbreviations: dep - depression, m - maxillae, pm - premaxillae, prid - palatal ridge. Arrows and numbers indicate alveoli or teeth and their respective position. Scale bar = 10 mm.