An Istiodactylid Pterosaur from the Nanaimo Group,Vancouver Island,British Columbia,Canada

Victoria M.ARBOURand Philip J.CURRIE

Laboratory for Vertebrate Paleontology,Department of Biological Sciences,University of Alberta,Edmonton,Alberta,Canada,T6G 2E9

An Istiodactylid Pterosaur from the Nanaimo Group,Vancouver Island,British Columbia,Canada

Victoria M.ARBOUR*and Philip J.CURRIE

Laboratory for Vertebrate Paleontology,Department of Biological Sciences,University of Alberta,Edmonton,Alberta,Canada,T6G 2E9

加拿大不列颠哥伦比亚省温哥华岛纳奈莫群的帆翼龙类化石

An unusual jaw found in a calcite nodule from Collishaw Point,Hornby Island,British Columbia (off the east coast of Vancouver Island)represents the first definitive pterosaur found in British Columbia,and the first istiodactylid from Canada.The nodule was derived from the Northumberland Formation (Nanaimo Group),a fossiliferous sequence known for producing numerous plants and invertebrate fossils,as well as sharks and mosasaurs.The pterosaur is represented by the anterior portion of the rostrum,including the anterior edge of the nasoantorbital fenestra,and numerous small,triangular teeth lacking denticles.These teeth are similar in overall morphology to the teeth of istiodactylids,but are smaller,more numerous,more tightly packed,and have proportionately smaller crowns.Although fragmentary,this specimen is diagnostic and likely represents a new genus of istiodactylid pterosaur.Its presence in the Late Campanian Northumberland Formation makes this the latest-occurring istiodactylid and extends the stratigraphic and geographic range of this enigmatic group of pterosaurs.Recently prepared nodules contain pterosaur postcranial material that may provide more information on the morphology of this istiodactylid,or may increase the diversity of pterosaur taxa from the Northumberland Formation.

* Corresponding author.E-mail:arbour@ualberta.ca.