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372
CARNIVORA

rule. Palaeontology has, however, made great strides since 1880, and the idea that the earlier mammals had more teeth than their descendants has not only received no confirmation, but has been practically disproved. Consequently Miss Albertina Carlsson had a comparatively easy task (in a paper published in the Zoologisches Jahrbuch for 1905) in demonstrating that the long-eared fox is a specialized, and to some extent degraded, form rather than a primitive type. This, however, is not all, for the lady points out that, as was suggested years previously by the present writer, the creature is really the descendant of the fossil Canis curvipalatus of northern India. This is a circumstance of considerable interest from a distributional point of view, as affording one more instance of the intimate relationship between the Tertiary mammalian fauna of India and the existing mammals of Africa.

In regard to the members of the dog-tribe as a whole, it may be stated that they are generally sociable animals, hunting their prey in packs. Many species burrow in the ground; none habitually climb trees. Though mostly carnivorous, feeding chiefly on animals they have chased and killed themselves, many, especially among the smaller species, eat garbage, carrion, insects, and also fruit, berries and other vegetable substances. The upper surface of the tail of the fox has a gland covered with coarse straight hair. This gland, which emits an aromatic odour, is found in all Canidae, with possibly the exception of Lycaon pictus. Although the bases of the hair covering the gland are usually almost white, the tips are always black; this colour being generally extended to the surrounding hairs, and often forming dark bars on the buttocks. The dark spot on the back of the tail is particularly conspicuous, notably in such widely separated species as the wolves, Azara’s dog and the fennec.

Although its existing representatives are very different, the bear-family or Ursidae, as will be more fully mentioned in the sequel, was in past times intimately connected with the Canidae. In common with the next two families, the modern Bear tribe. Ursidae are characterized by the very small tympanic bulla, and the broad paroccipital process, which is, however, independent of the bulla. The feet are more or less completely plantigrade and five-toed. The intestine has neither duodeno jejunal flexure nor a caecum; the prostate gland is rudimentary; but glands occur in the vasa deferentia; and the penial bone is cylindrical. As distinctive characteristics of the Ursidae, may be mentioned the presence of an alisphenoid canal on the base of the skull; the general absence of a perforation on the inner side of the lower end of the humerus; the presence of two pairs of upper and three of lower molars, which are mostly elongated and low-cusped; and the non-cutting character and fore-and-aft shortening of the upper sectorial, which has no inner root and one inner cusp (fig. 1, III.). Anal glands are apparently wanting. The short tail, bulky build, completely plantigrade feet and clumsy gait are features eminently characteristic of the bears.

The great majority of existing bears may be included in the typical genus Ursus, of which, in this wide sense, the leading characteristics will be as follows. The dentition is i3/3, c1/1, p4/4, m2/3 = 42; but the three anterior premolars, above and below, are one-rooted, rudimentary and frequently wanting. Usually the first (placed close to the canine) is present, and after a considerable interval the third, which is situated close to the other teeth of the cheek-series. The fourth (upper sectorial) differs essentially from the corresponding tooth of other Carnivora in that the inner lobe is not supported by a distinct root; its sectorial characters being very slightly marked. The crowns of both true molars are longer than broad, with flattened, tuberculated, grinding surfaces; the second having a large backward prolongation or heel. The lower sectorial has a small and indistinct blade and greatly developed tubercular heel; the second molar is of about the same length, but with a broader and more flattened tubercular crown; while the third is smaller. The milk-teeth are comparatively small, and shed at an early age. The skull is more or less elongated, with the orbits small and incomplete behind, and the palate prolonged considerably behind the last molar. Vertebrae: C. 7, D. 14, L. 6, S. 5, Ca. 8-10. Body heavy. Feet broad, completely plantigrade; the five toes on each well developed, and armed with long compressed and moderately curved, non-retractile claws, the soles being generally naked. Tail very short. Ears moderate, erect, rounded, hairy. Fur generally long, soft and shaggy.

Bears are animals of considerable bulk, and include among them the largest members of the order. Though the species are not numerous, they are widely spread over the earth, although absent from Africa south of the Sahara and Australasia. As a rule, they are omnivorous, or vegetable feeders, even the polar bear, which subsists for most of the year on flesh and fish, eating grass in summer. On the other hand, many of the brown bears live largely on salmon in summer. Among the various species the white polar bear of the Arctic regions, Ursus (Thalassarctus) maritimus, differs from the rest by its small and low head, small, narrow and simple molars, and the presence of a certain amount of hair on the soles of the feet. The typical group of the genus is represented by the brown bear (U. arctus) of Europe and Asia, of which there are many local races, such as the Syrian U. a. syriacus, the Himalayan U. a. isabellinus, the North Asiatic U. a. collaris, and the nearly allied Kamchadale race, which is of great size. In Alaska the group is represented by huge bears, which can scarcely claim specific distinctness from U. arctus; and if these are ranked only as races, it is practically impossible to regard the Rocky Mountain grizzly bear (U. horribilis) as of higher rank, although it naturally differs more from the Asiatic animal. On the other hand, the small and light-coloured U. pruinosus of Tibet may be allowed specific rank. More distinct is the North American black bear U. americanus, and its white relative U. kermodei of British Columbia; and perhaps we should affiliate to this group the Himalayan and Japanese black bears (U. torquatus and U. japonicus). Very distinct is the small Malay sun-bear U. (Helarctus) malayanus, characterized by its short, smooth fur, extensile tongue, short and wide head, and broad molars. Finally, the spectacled bear of the Andes, U. (Tremarctus) ornatus, which is also a broad-skulled black species, differs from all the rest in having a perforation, or foramen, on the inner side of the lower end of the humerus. A second genus, Melursus, represented by the Indian sloth-bear (M. ursinus), differs from the preceding in having only two pairs of upper incisors, the small size of the cheek-teeth, and the extensile lips. Ants, white-ants, fruits and honey form the chief food of this shaggy black species,—a diet which accounts for its feeble dentition (see Bear).

EB1911 Carnivora Fig. 6 - The Parti-coloured Bear, or Giant Panda.jpg

Fig. 6.—The Parti-coloured Bear, or Giant Panda
(Aeluropus melanoleucus).

The parti-coloured bear or giant panda (Aeluropus melanoleucus, fig. 6) of eastern Tibet and north-west China forms in some degree a connecting link between the bears and the true panda, although placed by Professor E. R. Lankester in the same family as the latter. In the number of the teeth, and to some extent in the character of the molars, as well as in the abbreviated tail, Aeluropus resembles the bears, but in the structure of the sectorial tooth, the presence of an extra radial carpal bone, and the osteology generally, it is more like the panda. In the absence of an alisphenoid canal to the skull it differs both from the latter and the bears, and thereby resembles the raccoons; while in having a perforation at the lower end of the humerus, it agrees with the spectacled bear, the panda and raccoons. The dentition is i3/3, c1/1, p4/3, m2/3; total 40; premolars increasing in size from first to last, and two-rooted except the first; the first upper molar with quadrate crown, broader than long; and the second larger than the first. Skull with the zygomatic arches and sagittal crest immensely developed, ascending branch of lower jaw very high, giving great space for attachment of temporal muscle, and facial portion short. Bony palate not extending behind the last molar. No alisphenoid canal. Feet bear-like, but soles more hairy, and perhaps less completely plantigrade. Fur long and thick; and tail extremely short. Humerus with a perforation on the inner side of the lower end; a very large extra radial carpal bone. The colour of this strange animal is black and white (fig. 6).

With the panda (Aelurus fulgens) we reach an undoubted representative of the Procyonidae, or raccoon tribe, differing, however, from all the rest except the doubtful Aeluropus, in its Asiatic habitat. If the latter be included, the family may be defined as follows. Molars 3/2, except in Aeluropus, with blunt or sharp cusps; no alisphenoid canal, except in Aelurus; humerus generally with a foramen; feet plantigrade; tail, except in Aeluropus, long and generally ringed.

In the panda the dentition is i3/3, c1/1, p3/4, m2/2; total 38; the first lower molar being minute and deciduous, and the upper molars broad with numerous and complicated cusps. Vertebrae: C. 7, D. 14, L. 6, S. 3, Ca. 18. Skull high and compressed, with an alisphenoid canal, a short facial portion, and the ascending branch of the lower jaw, as in Aeluropus, very tall. Face cat-like, with moderate, erect, pointed ears. Claws blunt. Tail cylindrical and