. Central Asiatic Expeditions of the American Museum of Natural History, under the leadership of Roy Chapman Andrews : preliminary contributions in geology, palaeontology, and zoology. Central Asiatic Expeditions (1921-1930); Scientific expeditions; Natural history; Scientific expeditions; Natural history. 1926] CRETACEOUS MAMMAL SKULLS, MONGOLIA 17 narrower than M2, with the heel not elongated. There are three heel cusps, a rather small hy'd and the closely approximated and somewhat higher en'd and hl'd. The heel is slightly broader than the trigonid and is basined. M1-2 are large but closely
. Central Asiatic Expeditions of the American Museum of Natural History, under the leadership of Roy Chapman Andrews : preliminary contributions in geology, palaeontology, and zoology. Central Asiatic Expeditions (1921-1930); Scientific expeditions; Natural history; Scientific expeditions; Natural history. 1926] CRETACEOUS MAMMAL SKULLS, MONGOLIA 17 narrower than M2, with the heel not elongated. There are three heel cusps, a rather small hy'd and the closely approximated and somewhat higher en'd and hl'd. The heel is slightly broader than the trigonid and is basined. M1-2 are large but closely similar. The protoconid is little if any higher than the metaconid, while the paraconid is reduced. The 1o\a- hypoconids project laterally; the entoconids are high. P4 is molariform, similar to Mi but higher and with a much shorter talonid and relatively elongated trigonid. The pr'd definitely but slightly overtops the me'd, while the pa'd, as before, is small. P4 is trenchant, two-rooted, consisting of a single cusp with a small unbasined heel; it is nearly as high as P'^. Neither No. 21707 nor the type shows the anterior region of the lower jaw, l)ut it is well seen in lateral view in the younger skull No. Fig. 15. Zalamhdalesteft lechei. Lower teeth, occlusal, outer and inner views. X %â P2 is much smaller than P3 and more procumbent. In front of it are three one- rooted teeth of increasing procumbency, all simply styliform. The posterior of these must be the canine, the other two 12-3- Ii is much enlarged, procumbent, and occludes between the enlarged upper incisors. Skull.âThe palate is a featureless, greatly crushed plate of bone without fenestrse and apparently with no postpalatal ridge. It is somewhat widened in the molar region, but narrower anteriorly and of nearly equal width for the entire length of the snout. The choanae are narrower than the molar region of the palate. The sutures of the palate are open, although the individual is certainly an old one.
Size: 1747px × 1430px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., andrews, books, booksubjectnaturalhistory, chapman, leadership, roy
