The Upper Cretaceous Chalk Formation of England and Britton Formation of Texas are home to two species of the pterosaur genus Cimoliopterus. C. cuvieri was first named by Bowerbank in 1851 as a species of Pterodactylus, then later transferred to Ornithocheirus. C. dunni was named by Myers in 2015. Rodrigues and Kellner named the genus Cimoliopterus in a 2013 review of the dozens of species assigned to Ornithocheirus over the years. The genus name translates to “Chalk wing – a reference to the Chalk Formation – and combines the Ancient Greek words “kimolia” and “pteron.” It should be noted that since the Greek root begins with a “kappa,” the initial “C” in this genus name should be pronounced with a “K” sound.
Cimoliopterus cuvieri is known from a partial snout measuring about 13 cm (5.5 inches) in length. The tips of the jaws curved up, and the snout had a rounded crest. The crest began to rise above the 7th tooth position and followed a sine-wave-like curve. The crest superficially resembled what’s seen in Anhanguera, but the crest began much further forward in Anhanguera. Cimoliopterus cuvieri also has no lateral spoon-like expansion of the jaw tips seen in Anhanguera, and the snout was remarkably tall and narrow, being less than 1.5 cm (1/2 inch) wide. There are eleven tooth positions in the fragment, with the first tooth position being directed forward. It probably had more teeth in the missing portions of jaw. When complete, its skull may have been about 40 cm (16 inches) long, with a wingspan of 2.0 - 2.5 m (6.5 - 8 feet).
A different species, Cimoliopterus dunni, is also known from a partial snout, this time measuring about 17 cm (7 inches) in length. Like C. cuvieri, it has upturned jaw tips and a sine-wave-like crest, but differs in that its crest begins above the fourth tooth position and is proportionally taller. Also like C. cuvieri, it lacks any spoon-like expansion and is very tall and narrow. Thirteen tooth positions are present in the specimen, and like C. cuvieri, the first tooth was directed forward. When complete, its skull may have been about 50 cm (20 inches) long, with a wingspan of 2.5 - 3.0 m (8-10 feet).
Both Rodrigues and Kellner as well as Myers placed Cimoliopterus into phylogenetic analyses to determine its relationships to other pterosaurs. Rodrigues and Kellner found that it was at the base of the ornithocheirid lineage (although they did not use that terminology). Myers also found that Cimoliopterus was a basal ornithocheirid, and that both species were closely related to Aetodactylus halli.
Cimoliopterus, like all ornithochreirids, was an aerial fisher. Both species lived about 95 million years ago, and are found in rocks deposited under shallow, warm-water seas, ideal fishing grounds.
Ornithocheiridae
