. The dinosaurs of North America. Dinosaurs. MARSH.] TOROSAURUS. 215 nasal horn core is compressed, with a sharp apex directed forward. The frontal horn cores are large and strongly inclined to the front, extending apparently in advance of the nasal protuberance. The long, slender squamosals diverge rapidly as they extend backward, their outer margins being nearly on a line with the facial borders in the maxillary region. The parietal forms more than half of the upper surface of the skull, and' is the most characteristic element in its structure. In the poste- rior part are two very large aper
. The dinosaurs of North America. Dinosaurs. MARSH.] TOROSAURUS. 215 nasal horn core is compressed, with a sharp apex directed forward. The frontal horn cores are large and strongly inclined to the front, extending apparently in advance of the nasal protuberance. The long, slender squamosals diverge rapidly as they extend backward, their outer margins being nearly on a line with the facial borders in the maxillary region. The parietal forms more than half of the upper surface of the skull, and' is the most characteristic element in its structure. In the poste- rior part are two very large apertures, oval in outline, with their outer margin at one point formed by the squamosal. The rest of the border is thin and somewhat irregular, showing that the openings are true. Fig. 54.—STjbII of Torosauritsgladius Marsh ; seen from above. One-twentieth natural size. c. snpratempnral fossa; e', epijugal bone;/', parietal fontanelle; ht horn core; k', nasal horn core; p, parietal; 8, squamosal; z, pineal foramen (?). fontanelles. This is still better seen in the second species represented in the same plate, fig. 2, and in fig. 54, above. In the latter specimen, however, these vacuities are entirely in the parietal, a thin strip of bone separating them on either side from the squamosal. A second pair of openings, much smaller, apparently the true supratemporal fossce, are shown in the type specimen. These are situated mainly between the parietal and squamosal, directly behind the bases of the large horn cores (PI. LXII, fig. 1, c). The same apertures are represented in the genus Triceratops by oblique openings, as in the skull shown on PL LX, fig. 3, c, where the front border of each is formed by the postfrontal. Between these openings, in the type of Torosaurus, is a third pair of apertures (PI. LXII, fig. 1, &). These are quite small, nearly circular in outline, and entirely in the parietal, although probably connected. Please note that these images are extracted from sca
Size: 1925px × 1297px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherwashi, bookyear1896
