Ardeadactylus: an identity rebuilt after loss

Ardeadactylus longicollum spent much of its scientific history inside the genus Pterodactylus. Its original skeleton was destroyed during the Second World War, so the modern concept rests on a later neotype and a small number of referred specimens. Their proportions distinguish a long-necked pterosaur from Pterodactylus antiquus, but the loss of the original limits direct comparison. This profile is part of the pterosaur catalogue.

Evidence note

The neotype and another referred skeleton preserve the long neck, narrow skull and wings used to recognise Ardeadactylus. The lost original cannot be re-examined, and feeding behaviour or soft-tissue appearance remain uncertain.

Quick facts

A lost type and a replacement

Hermann von Meyer named Pterodactylus longicollum in 1854 from a skeleton in the Upper Jurassic slab limestones of Germany. The specimen was destroyed during the Second World War. Drawings and casts retain some information, but they cannot replace a new examination of the original bones.

In 1970, Peter Wellnhofer designated SMNS 56603 from Nusplingen as a neotype. Christopher Bennett's revision of Pterodactylus later separated the long-necked form as Ardeadactylus in 2013. A further skeleton in the Jura Museum at Eichstätt has been referred to the genus. Researchers have discussed how the ages of the localities and the neotype's relationship to the lost original fit together, so the referral is not a simple return to the first specimen.

Skull, teeth and long neck

The skull is elongated and narrows towards the front. Conical teeth occupy mainly the anterior parts of the jaws, leaving the rear portion toothless. This arrangement differs from pterosaurs with teeth along most of the jaw margin. The neck vertebrae are elongated, a feature reflected in the species name longicollum, meaning “long-necked”.

The neotype has relatively long wings and an estimated span of about 1.45 metres. The Eichstätt specimen may have been somewhat larger. These are estimates for particular skeletons, not a maximum size for the whole species. A 2021 study described a series of fused vertebrae in the neotype as a notarium, a stiffened section that reinforced the shoulder region against flight loads. Although the skeleton is incomplete, the fusion shows that these bones were not merely laid together by chance.

Flight above Jurassic lagoons

The German lithographic limestones formed in islands and shallow lagoons. Long wings are compatible with economical flight over open water. The narrow jaws and front teeth could have caught small fish or invertebrates, but no meal is known. The heron-like interpretation suggested by the genus name does not prove that Ardeadactylus waded in deep water; the long legs required for that behaviour are not established for the genus.

Trackways assigned to other pterosaurs show that some walked on all four limbs. They cannot automatically be assigned to Ardeadactylus. The better-known Pterodactylus offers a useful comparison for a German Jurassic pterosaur, but it does not fill missing parts of this animal's record.

What is and is not preserved

The skeletons support an elongated neck and jaws, forward-set teeth and long wings. No soft head crest is known. The colour of the membrane, density of body fibres, shape of the tongue and exact way of catching prey are not established. Reconstructions can make these choices plausible, but they should not present them as observations from the fossils.