Hornby Island Azhdarchid

Description

All of the pterosaurs that lived at the very end of the Cretaceous were giants and belonged to the marine-hunting pteranodontids and nyctosaurids, or the terrestrial-hunting azhdarchids. Conventional wisdom seemed to imply that birds had out-competed pterosaurs in most of the small to medium-sized flying vertebrate niches. 

That is until a cat-sized fossil azhdarchid was discovered in Late Cretaceous sediments of the Northumberland Formation exposed on Hornby Island, British Columbia. Hornby Island lies off the east coast of Vancouver Island between the towns of Campbell River and Nanaimo. The fossils were found in a small nodule and consist of a humerus and some dorsal vertebrae. 

Although the remains are incomplete, they show that this pterosaur is most closely related to the giraffe-sized azhdarchids like Quetzalcoatlus and Hatzegopteryx, especially in details of the humerus. Was this specimen a juvenile of one of the very large azhdarchids, or was it an adult of a small unknown species? To find out, scientists conducted detailed examinations and comparisons of the bone texture of this fossil and other fossil azhdarchids under a microscope. They found that this specimen was not yet fully grown, but exhibited features that are seen in near-adult azhdarchid specimens.

Because of the incomplete nature of the specimen, it wasn’t given a scientific name by the authors. This specimen expands our knowledge about the last pterosaurs, as well as our knowledge of Late Cretaceous pterosaurs, especially those in the far west of North America.