Gregory J. Retallack, Jessica M. Theodor, Edward B. Davis, Samantha S. B. Hopkins & Paul Z. Barrett (2018)
First dinosaur (Ornithopoda) from Early Cretaceous (Albian) of Oregon, U.S.A.
Journal of Vertebrate Paleontology e1486847 (advance online publication)
DOI: 10.1080/02724634.2018.1486847
A fossil toe bone discovered in 2015 by GJR is the first diagnostic, nonavian dinosaur fossil from Oregon, a state whose, Mesozoic rocks are mostly marine (Orr and Orr, 2012). This discovery, is novel evidence of Cretaceous terrestrial environments, and faunas in Oregon. The pedal phalanx was recovered from the, midâCretaceous (AlbianâCenomanian) Hudspeth Shale and is, here identified informally as the âMitchell ornithopod.â This new, ornithopod fills a geographic gap between the Early Cretaceous, (Aptian) âOno ornithopodâ of northern California (Hilton et al.,, 1997) and the Late Cretaceous (Campanian) âSucia Island, theropodâ of Washington (Peecook and Sidor, 2015), as one of, the few nonavian dinosaur specimens known from marine rocks, of the Pacific Northwest. Other Pacific coastal nonavian dinosaurs, from southeast Alaska to Baja California reviewed by Peecock, and Sidor (2015) include a possible Oregon hadrosaur sacrum, from the Late Cretaceous (Maastrichtian) Cape Sebastian, Sandstone (Orr and Orr, 2012), but our examination of this, unprepared specimen cannot yet determine whether it was a dinosaur,, marine turtle, or plesiosaur.Â