Notes on the systematic position of the wolves of the canis dirus group Author Merriam, John C. text Bulletin of the Department of Geology. 1918 1918-04-29 10 531 533 https://www.biodiversitylibrary.org/item/139018 journal article 8844 10.5281/zenodo.4443191 aad315b8-2a43-42f5-b009-df49d7d0e3b3 4443191 Considering that the several types included in the dírus group represent at least three quite distinct forms, in all of which there appears a group of common characters sharply distinguished from those of other Wolves, there is ample justification for distinguishing this group as a separate genus or subgenus for which the name Aenocyon “ may be applied. The generic characters of Aenacg/on are found in the massiveness of skull and dentition, extreme overhang of the inion, shortness of the basicranial region posterior to the glenoid fossae, massiveness of the upper and lower carnassials, reduction of thc hypocone of M1, and probably in characters of the Skeleton not as yet available from other material than that obtained at Rancho La Broa. The genus Aenocyon was widely distributed over North America in Pleistocene time. Its range extended from the east to the west coast and from Mexico at least as far north as the upper portion of the Mississippi Valley. Whether its geographic range extended into the Canadian area is as yet uncertain. It is possible that the timber wolves of the Canis accídcntalís group occupied the northern portion of the continent eonteinporaneously with the maximum development of the Aenocyon group in the Sonoran region. The geologic range of Aenacyon is also still to be determined. A somewhat puzzling feature in the distribution of these wolves is found in their absence from the Pleistocene of Fossil Lake, Oregon. The Fossil Lake deposits contain a large vertebrate fauna representing a wide variety of forms and ranging from the largest to the smallest mammals and birds, and including representation of some of the most delicate osseous structures. Wolf remains are well known in this fauna, including bones of both timber wolves and coyotes, but as yet no representation of Aenocyon has been recognized in the collections from this locality. Had Acnncyon diras or any other member of the group been present in this region in numbers comparable to those known elsewhere in the Pleistocene it would presumably have left at least some trace of its presence. Its absence may be due to limited northern range, or to dept» sition of the Fossil Lake beds at a period earlier, or perhaps later, than that of Rancho La Brea and of other deposits in which specimens repre sentative of Aenucyon have been found. lsellai-(ls, E, H., 8th Ann. Rep. Florida Geol. Surv., pp. 152757, pls, 24, 30, figs. 1, 3, 1916. menos; terrible, dreadful; cyan: wolf. The recognized species of Aenocyon are A. dirus , A. milleri , and A. ayersi .