. Catalogue of the fossil Mammalia in the British museum, (Natural History). Mammals, Fossil. TTNGULATA. alternate arrangement; there are never fewer than three such ridges in the last milk- and the first true molars ; and the intervening valleys may be either entirely open, or blocked by accessory tubercles, or completely filled with cementJ. Family DINOTHERIID^]. All the teeth of the permanent series are in use at the same time, the premolars succeeding the milk-molars in the normal manner. In the one known genus none of the cheek-teeth have cement, or carry more than three ridges : in the t
. Catalogue of the fossil Mammalia in the British museum, (Natural History). Mammals, Fossil. TTNGULATA. alternate arrangement; there are never fewer than three such ridges in the last milk- and the first true molars ; and the intervening valleys may be either entirely open, or blocked by accessory tubercles, or completely filled with cementJ. Family DINOTHERIID^]. All the teeth of the permanent series are in use at the same time, the premolars succeeding the milk-molars in the normal manner. In the one known genus none of the cheek-teeth have cement, or carry more than three ridges : in the true molars these ridges are continuous and the valleys open; but in the upper premolars the former are more or less interrupted, and are connected by a longi- tudinal external ridge, a similar submedian ridge occurring in the lower premolars. This lophodont structure of the premolars is a character connecting DinotJierium with the Perissodactyla, and is not improbably evidence of their original community of descent. In section the incisors do not present decussating striae. The upper cheek-teeth of DinotJierium giganteum are figured in the accom- panying woodcut. ' Fig. DinotJierium giganteum.—-The left upper cheek-dentition ; from the Middle Miocene of Samaran (Gers), France. £. p, premolars ; a, true molars. (After Gaudry's ' Enchainements.') 1 For other characters see Marsh, ' Monograph of the Dinocerata,' pp. 174-5 (1884), and Flower, 'Encyclopaedia Britannioa,' 9th ed. toI. xv. pp. 423-5 (1883).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). Dept. of Geology; Lydekker, Richard, 1849-1915. London, Printed by order of the Trustees
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Keywords: ., bookauthorlydekker, bookcentury1800, bookdecade1880, bookyear1885
