MERRIAM: THE FAUNA OP RANCHO LA BREA. 223 



Diagnostic Charactees 



The largest species of Canis known from the faunas of North America. Form 

 and proportions in general near those of the existing timber wolves; head 

 relatively larger and feet relatively smaller than in the large Recent timber 

 wolves of the Canis pambasileus type. Skull attaining a length of 310 mm. 

 or more; relatively broad across the palate, frontal region, and zygomatic 

 arches. Sagittal crest high, inion showing an extraordinary backward projec- 

 tion. Posterior extremities of nasal bones extending relatively far back. Nasal 

 processes of frontals relatively short. Postpalatine foramina opposite posterior 

 ends of superior carnassials. Optic foramen and anterior lacerated foramen 

 close together in a common pit. Upper and lower carnassials relatively large 

 and massive. P* with reduced cleuterocone, M 1 with greatly reduced hypocone, 

 Mi with a small metaconid, P 2 and P 2 often without posterior cusps or tubercles. 



Skull 



The skull in this species (figs. 1, 2, 3, and 4) is larger than the cranium of any 

 other wolf known to the writer. The basal length from the anterior end of 

 the premaxillaries to the posterior side of the occipital condyles in one of the 

 large specimens measured (no. 10856) is 282 mm. The total length of the 

 skull projected on the plane of the palate, including the extraordinary back- 

 ward projection of the inion, may be more than 310 mm. In spite of the great 

 length, the width measured across the palate, between the orbits, across the 

 postorbital processes of the frontals, and across the zygomatic arches, is 

 relatively large, making the skull very massive. 



The facial region is characterized by extraordinary backward extension of 

 the nasal bones, which reach a short distance behind a line connecting the most 

 nearly approaching points on the orbits. The nasal processes of the frontals 

 are generally relatively short. In the lateral region of the face an area at the 

 anterior root of the zygomatic arch is generally very sharply depressed and 

 forms a characteristic feature. On the inferior side of the zygomatic arch the 

 attachment of the masseter muscles is very strongly marked, and ends anter- 

 iorly on a prominent knob situated at the most inferior point on the suture 

 between the jugal and the maxillary. 



The frontal region is relatively broad, the postorbital processes of the 

 frontals being very largely developed. The frontal region shows only a slight 

 median depression, which may be somewhat accentuated toward the nasal and 

 parietal borders of the frontals. The sagittal crest is uniformly high, and is 

 characterized especially by the extraordinary backward extension, which much 

 exceeds that of the other wolves. 



