A new species of Coloborhynchus (Pterosauria, Ornithocheiridae) from the mid-Cretaceous of North Africa

Abstract

Pterosaur faunas experienced dramatic turnover between the Early and Late Cretaceous, but fossils documenting this transition are rare. The mid-Cretaceous Kem Kem beds of Morocco are one of a handful of localities preserving pterosaurs from this important interval. Previously reported taxa from the Kem Kem beds include the ornithocheirid Siroccopteryx moroccensis, the azhdarchoids Alanqa saharica and Xericeps curvirostris, an unnamed tapejarid, and a putative pteranodontid. Here, a new species of ornithocheirid, Coloborhynchus fluviferox sp. nov., is described on the basis of a well-preserved anterior rostrum fragment. It is assigned to Coloborhynchus based on the presence of an anteriorly directed first tooth pair protruding from a palatal surface, which is deflected dorsally by 90 degrees. The new specimen differs from Siroccopteryx moroccensis and is distinguished from other species of Coloborhynchus by numerous characters, including an anterior palatal surface that defines a high isosceles triangle with two shallow, subcircular depressions located dorsal to premaxillary tooth pair one. The central region of alveoli for the first tooth pair is level with the dorsal borders of the second tooth pair and the mediodorsal crest rises steeply forming a blunt termination of the rostrum. The new species brings the number of pterosaur species from the Kem Kem beds to at least 5. The Kem Kem pterosaur assemblage resembles other Early Cretaceous faunas in having a high diversity of toothed forms, but also resembles latest Cretaceous faunas in having several edentulous azhdarchoids.

Geology and paleontology of the Upper Cretaceous Kem Kem Group of eastern Morocco

“…Among skeletal remains, fragments of the rostrum and mandibular symphysis of edentulous pterosaurs (Figs 96-101), seemingly all azhdarchoids, outnumber all other skeletal elements described so far. The relatively common occurrence of azdarchoid jaw remains is in sharp contrast to the comparatively rare incidence of ornithocheirid jaw fragments which, to date, number only six examples (Mader and Kellner 1999, Jacobs et al 2019. This disparity is perhaps due to the unusually robust construction of the jaws of azhdarchoids in which the tips of rostra and mandibular symphyses are composed of relatively thick cortical bone with only a small central lumen (Fig.…”

“…The Kem Kem beds have revealed an important and remarkably diverse vertebrate assemblage including elasmobranchs, osteichthyes, and basal sarcopterygians (Choubert 1939, Tabaste 1963, Wenz 1981, Forey 1997, Forey and Grande 1998, Taverne and Maisey 1999, Cavin and Dutheil 1999, Dutheil 1999a, 1999b, Cavin and Brito 2001, Taverne 2000, 2004, Cavin and Forey 2001a, 2001b, Filleul and Dutheil 2001, 2004, Cavin and Forey 2004, Forey and Cavin 2007, Martill and Ibrahim 2012, amphibians (Rage and Dutheil 2008), lepidosauromorphs (Rage and Dutheil 2008, Apesteguía et al 2016a, Klein et al 2017, turtles (Gmira 1995, Tong and Buffetaut 1996, Gaffney et al 2002, 2006, crocodyliforms (Buffetaut 1976, Larsson and Sues 2007, Sereno and Larsson 2009 Lapparent de Broin 2016, Young et al 2017, pterosaurs (Wellnhofer and Buffetaut 1999, Mader and Kellner 1999, Ibrahim et al 2010, Rodrigues et al 2011, Martill and Ibrahim 2015, Jacobs et al 2019, non-avian dinosaurs…”

“…Several authors have suggested that Siroccopteryx may be synonymous with Coloborhynchus (Unwin 2001, Veldmeijer 2003, Ibrahim et al 2010. Conversely, Rodrigues and Kellner (2008) and Jacobs et al (2019) have argued that it represents a genus distinct from other ornithocheirids. LINHM 016 exhibits several distinctive features including an unexpanded, near parallel profile, in palatal view (Fig 95B), a relatively narrow, deep rostrum, a rounded anterior profile of the rostrum in lateral aspect ( Fig 95A) and a posteriorly displaced rostral crest.…”

Ferrodraco lentoni gen. et sp. nov., a new ornithocheirid pterosaur from the Winton Formation (Cenomanian–lower Turonian) of Queensland, Australia

“…45 ), and the Albian–lower Cenomanian Kem Kem Beds (summarised by Jacobs et al . 46 ). At present, Ornithostoma sedgwicki 47 is the only edentulous pterosaur reported from the Cambridge Greensand; nevertheless, this consistent biogeographical pattern suggests that future excavations in the Winton Formation might also result in the discovery of azhdarchoids.…”

First complete pterosaur from the Afro-Arabian continent: insight into pterodactyloid diversity

“…This is particularly true for pterosaurs, an extinct group of flying reptiles that includes the major powered flying vertebrates for almost 160 mya 2,3 . The main African records of this group are restricted to isolated elements from the Jurassic deposits of Tendaguru 4–6 from Tanzania, and the Upper Cretaceous Kem Kem Beds (Cenomanian) 7–11 and Ouled Abdoun (Maastrichtian) 12,13 from Morocco. The most complete pterosaur specimens from the Afro-Arabian continent have been recovered from Cenomanian marine deposits of Lebanon 14 (Fig.…”