SUBOBDER B FISSIPEDIA 75 



earliest fossil forms appear in the Pliocene of Europe and Asia. Certain 

 Canidae of the North American Miocene, Aelurodon, Hyaenognathus, exhibit 

 great similarity in dentition to the Hyaenidae. 



Lycyaena Hensel (Agnotherimn, Agnocyon Kaup) and Hyaenidis Gaudry, 

 are distinguished from Hyaena by the more slender teeth and the presence of 

 a small M^. Basal Pliocene ; Pikermi, Eppelsheim, Baltav^r, and Bessarabia. 



Hyaena Linn. (Fig. 105) appears first in Lower Pliocene of Pikermi, Samos, 

 Maragha, Baltavar, Mont Leb^ron, Bessarabia. H. exima Roth and Wagner ; 

 H. salonicae Andrews (Salonika). H colvini, H. macrostoma Lydekker, H. 

 felina, H. sivalensis Bose, in the Pliocene of Siwalik. H gigantea Schlosser, in 

 China. H. arvernensis Croiz. & Job., in the Upper Pliocene of Auvergne 

 and valley of Arno. In Roussillon and Pleistocene of Mosbach, H. perrieri 

 Croiz. & Job. and H. brevirostris Aym. In later Pleistocene of South 

 Europe^ H. striata, resembling H. arvernensis ; H. crocuta var. spelaea Goldf . 

 in early European Pleistocene, greatly resembling H. perrieri. Found also in 

 the Karnul Caves of India and in the Pleistocene of China, H. sinensis Owen. 



, Family 7. Felidae. Cats.^ 



' ' • strongly developed, antero-posterior borders sharpened. 



Upper carnassial elongated, trenchant, with inner tubercle and three outer cusps. 

 Lower carnassial with two converging blades, developed from paraconid and profo- 

 conid, rudimentary talonid, unusually with weak metaconid. M^ and M^ always 

 small. Number of premolars constantly reduced, the remaining premolars being 

 provided with lateral cusps. Auditory bidla well rounded, septate, and lacking 

 prolonged external meatus. Cranium inflated, muzzle short. Humerus with 

 entepicondylar foramen. Extremities long and slender, digitigrade. Manus 

 pentadactyl, pes more often tetradactyl. Claws retractile. Os penis small. 



The Felidae are universally distributed except in Australia and New 

 Zealand, both at the present day and as fossils ; they first appear in Europe 

 and almost simultaneously in North America. They possess a reduced but at 

 the same time highly specialised dentition, adapted for the cutting of flesh, while 

 the skeleton combines the greatest strength with the utmost grace of form. 



They are sharply differentiated from the other carnivores, and even 

 their most remote ancestor yields no satisfactory information concerning their 

 origin, all possessing the same typical characteristics. If the Miocene genus 

 Proailurus, which Filhol regards on account of its similarity with the recent 

 Cryptoprocta as ancestor of the Felidae, is really a member of this family, it 

 is undoubtedly the ancestor of the true cats, but not of the Machairodontinae, 

 since these are already present in the Oligocene or even the Upper Eocene. 

 A possible derivation of both Felines and Machairodonts may be from 

 Dinictis, according to Matthew. Hoplophoneus from the same formation as the 

 latter is certainly more in line with the Machairodonts. 



Subfamily 1. Machairodontinae. 



Carnassial slightly notched. Inner cusp of P small. Upper C sabre-like, becoming 

 gradually larger, lower C gradually smaller. P^ small, P, rudimentary or wanting. 



^ Fahrini, E. /., Machairodus di Valdarno. Boll. Comit. Geol. Koma, 1890. — Matthew, W. D., 

 The Phylogeny of the Felidae. Bull. Amer. Mus. Nat. Hist., 1910. 



