Coloborhynchus clavirostris Owen, 1874

Holgado, Borja & Pêgas, Rodrigo V., 2020, A taxonomic and phylogenetic review of the anhanguerid pterosaur group Coloborhynchinae and the new clade Tropeognathinae, Acta Palaeontologica Polonica 65 (4), pp. 743-761 : 746-747

Coloborhynchus clavirostris Owen, 1874

Holotype: NHMUK PV R1822, an anterior portion of the rostrum displaying the alveoli from the 1st to the 6th pair of teeth ( Fig. 1 ).

Type locality: St. Leonards­on­Sea, East Sussex, England.

Type horizon: Hastings Group (late Berriasian/Valanginian).

Material.— Holotype only.

Diagnosis.—Coloborhynchine distinguished by the following autapomorphies: oval depression on the anterior palatal surface beneath the first pair of alveoli; second, third and fourth pairs of alveoli located laterally; fifth and sixth pairs of alveoli located more medially than the preceding alveoli on the base of the palatal ridge; anterior part of the palatal ridge bordered by two shallow longitudinally elongated depressions (from Rodrigues and Kellner 2008).

Remarks.—Following Rodrigues and Kellner (2008, 2013), who reviewed the taxonomy of the genus Coloborhynchus , we consider Coloborhynchus as restricted to the type species, Coloborhynchus clavirostris . For further details on the taxonomic history of the genus Coloborhynchus and the species Coloborhynchus clavirostris see the Introduction section above.

Genus Nicorhynchus nov.

ZooBank LSID: urn:lsid:zoobank.org:act:36FDC3A2­EA09­4AA3­B738­E79CA3EB6E06

Type species: Ornithocheirus capito Seeley, 1870 ; see below.

Included species: Nicorhynchus capito ( Seeley, 1870) , and Nicorhynchus fluviferox ( Jacobs, Martill, Ibrahim, and Longrich, 2019) .

Etymology: A combination of the Old English nicor, knucker (a kind of water dragon), and Ancient Greek ῥύγχος (rhúgkhos, Latinised as rhynchus), snout; in reference to the fact that the new taxon represents a piscivorous flying reptile from marine and fluvial deposits, represented by fragmentary snouts.

Diagnosis.—Coloborhynchines with a deltoid facet (sensu Jacobs et al. 2019) higher than wide; deltoid facet dorsolateral edges bearing anteriorly­facing ridges; an anteroventral depression between the first and second pairs of upper teeth; and a palatal depression posterior to the second pair of upper teeth.

Remarks.— Rodrigues and Kellner (2008, 2013) were the first workers to suggest that “ Coloborhynchus ” capito required a new generic name, affirming that referral to the genus Coloborhynchus or any other genus was open to debate. These workers regarded that “ C. ” capito differed from Coloborhynchus clavirostris in lacking a flat rostral surface; presumably because “ C. ” capito bears a depression bordered by protruding ridges on the dorsal region of the deltoid facet. Furthermore, Rodrigues and Kellner (2013) noticed that “ C. ” capito shared with Uktenadactylus wadleighi a dorsal sulcus on the anterodorsal surface of the premaxillary crest, as well as a concave anterodorsal margin of the premaxillary crest in lateral view ( Rodrigues and Kellner 2008, 2013); hinting at a possibly closer relationship with Uktenadactylus wadleighi instead of Coloborhynchus clavirostris . However, Rodrigues and Kellner (2008; 2013) prevented from erecting a new genus for “ C. ” capito until better material would come to light.

Even though the dorsal sulcus on the premaxillary crest could be viewed as a possible sign of abrasion, we agree with Rodrigues and Kellner (2013) that this feature is most likely genuine, given that: (i) Seeley (1881) has affirmed that the bone surface in the holotype of “ Ornithocheirus ” reedi was smooth and thus most likely not abraded; and (ii) it is similar to the conditions seen in Uktenadactylus wadleighi and Nicorhynchus fluviferox ( Rodrigues and Kellner 2008; Jacobs et al. 2019). As for the strongly concave anterodorsal margin of the premaxillary crest, we highlight that the taxonomic relevance of this feature must be viewed with caution, since cranial crest shape is influenced by ontogeny (e.g., Manzig et al. 2014; Pinheiro and Rodrigues 2017).

Subsequently, Jacobs et al. (2019, 2020) described “ Coloborhynchus ” fluviferox and noticed it shared several traits with “ C. ” capito (a relatively higher deltoid facet; a palatal depression posterior to upper tooth position two) and, to a lesser extent, Uktenadactylus wadleighi (a sulcus running along the anterodorsal surface of the premaxillary crest; which is confidently not a sign of abrasion at least in the holotype of U. wadleighi and in FSAC­KK 5024; see further below). Even though these workers prevented from presenting a revision of the genus Coloborhynchus , they affirmed that “ C. ” fluviferox was apparently closely related to Cambridge Greensand coloborhynchines and speculated the possibility that the genus Coloborhynchus sensu Martill and Unwin (2012) could actually be split into further genera ( Jacobs et al. 2019).

In this way, supporting the suggestions of Rodrigues and Kellner (2008) as well as of Jacobs et al. (2019), we erect the new genus Nicorhynchus for the reception of N. capito and N. fluviferox (see below). In the present work, we recover a monophyletic Nicorhynchus genus, as the sister­group of a monophyletic Uktenadactylus (see further below).

Stratigraphic and geographic range.—Albian to Cenomanian; Cambridge Greensand, England; Kem Kem Group, Morocco.

Figures

Fig. 1. Anhanguerid pterosaur Coloborhynchus clavirostris Owen, 1874, NHMUK PV R1822, St. Leonards­on­Sea, East Sussex, England, late Berriasian–Valanginian. In anterior (A1), left lateral (A2), palatal (A3), dorsal (A4), and right lateral (A5) views. Photographs from NHMUK data portal collections (https://data.nhm.ac.uk/).