Comodactylus

Comodactylus is a genus of "rhamphorhynchoid" pterosaur from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Wyoming, United States, named for a single wing metacarpal.

In 1879 collector William Harlow Reed sent some fossil material he had dug up at Como Bluff in Quarry N° 9, or the "Mammal Quarry", to his employer Professor Othniel Charles Marsh at New Haven. Among it was the bone of a pterosaur, that was subsequently filed, stored and forgotten.

However, in 1981 Peter Galton named, based on this bone, the genus Comodactylus. The type species is Comodactylus ostromi. The genus name is derived from Como Bluff and Greek daktylos, "finger", referring to the wing finger typical of pterosaurs. The specific name honours John Ostrom.

The holotype is YPM 9150, consisting of an intact fourth metacarpal, 57.5 millimetres long. The metacarpal is quite robust with especially the proximal end, that touching the wrist bones, being very expanded. Such proportions are typical for basal pterosaurs, so Comodactylus was not a member of the, advanced, Pterodactyloidea. To what other pterosaur group it did belong has, however, proven difficult to determine, due to a lack of information. The metacarpal is the only known part of the animal. Kevin Padian in 1989 considered it a nomen dubium. David Unwin in 1993 suggested an affinity with Nesodactylus.

The wingspan has been estimated at 2.5 metres (8.2 ft), exceptionally large for a pterosaur not belonging to the Pterodactyloidea. Comodactylus was also the first pterosaur outside of that group, that was found in America.