Dimorphodon (/daɪˈmɔːrfədɒn/ dy-MOR-fə-don) was a genus of medium-sized pterosaur from Europe during the early Jurassic Period (about 201-191 million years ago).

The body structure of Dimorphodon displays many "primitive" characteristics, such as, according to Owen, a very small brain-pan[2] and proportionally short wings.

[5] This region of Britain is now a World Heritage Site, dubbed the Jurassic Coast; in it layers of the Blue Lias are exposed, dating from the Hettangian-Sinemurian.

[2] An additional species of Dimorphodon, D. weintraubi, was named by James Clark et al in 1998 from a partial skeleton recovered in siltstones from the site Huizachal Canyon in La Boca Formation in Tamaulipas, Mexico, from the Early Jurassic (Pliensbachian), where remains of sphenodontians, dinosaurs and mammaliaforms have also been found.

[11] It is known from the type specimen, IGM 3494 (Instituto Geológico de México, of the Universidad Nacional Autónoma de México), that comprises articulated pieces of the skeleton including the posterior part of skull, four cervical vertebrae, the scapulocoracoids, left humerus, partial right wing and right leg distal to mid tibiotarsus.

This specimen is larger than D. macronyx and the well preserved foot of it shows that pterosaurs do not have a digitigrade posture in their hindlimbs, but that it have a plantigrade gait, as has been inferred from footprints.

Later, it became common to depict it as a piscivore (fish eater), though biomechanical studies support Buckland's original insectivore idea better, and inconsistent with the animal's habits (see flight below).

This, along with the short and high skull and longer, pointed front teeth suggest that Dimorphodon was an insectivore, though it may have occasionally eaten small vertebrates and carrion as well.

[15] Mark Witton has argued that the animal was a specialised carnivore that was too large for an insectivorous diet, though he did acknowledge that it still might have ate large insects, and thus specialised to hunt relatively small vertebrates, with its relatively weak jaw musculature indicating that it probably ate proportionally small prey.

[16] Dental microwear examinations confirm its status as a vertebrate predator, as opposed to several other insectivore or piscivore early pterosaurs, though the study does acknowledge that the possibility of consuming relatively softer invertebrates cannot be excluded entirely.

However, more recent studies show that the animal was actually a rather poor flyer: its wings are proportionally short in relation to the body and its skeleton rather robust, offering very little gliding potential.

In life, Dimorphodon probably relied on frantic short flights in the same manner as modern fowl, tinamous and woodpeckers, being unable to fly for long distances and probably only taking to the air as a last resort.

[2] However, his rival Harry Govier Seeley, propagating the view that pterosaurs were warm-blooded and active, argued that Dimorphodon was either an agile quadruped or even a running biped due to its relatively well developed hindlimbs and characteristics of its pelvis.

[21] Like most non-pterodactyloid pterosaurs, Dimorphodon was a competent climber, possessing proportionally large and curved ungals and a low center of gravity.