. Bulletin - United States National Museum. Science. 178 tTNTTED STATES NATIONAL MtrSEUM BULLETIN 2 47. Figure 77.—^Dorsal view of skull, USNM 16119, of Parietobalaena palmeri Kellogg. Reconstruction based on four skulls. For abbreviations, see figure 79. these median rostral elements (fig. 77) are extended back- ward nearly to the level of the center of the orbit. In front of the nasal fossa (USNM 23022; length, 260 ± mm.) in the narrow mesorostral trough, the premaxillaries are in contact to their anterior ends. In front of the anterior end of the vomer (USNM 23022; length, 785 mm.),
. Bulletin - United States National Museum. Science. 178 tTNTTED STATES NATIONAL MtrSEUM BULLETIN 2 47. Figure 77.—^Dorsal view of skull, USNM 16119, of Parietobalaena palmeri Kellogg. Reconstruction based on four skulls. For abbreviations, see figure 79. these median rostral elements (fig. 77) are extended back- ward nearly to the level of the center of the orbit. In front of the nasal fossa (USNM 23022; length, 260 ± mm.) in the narrow mesorostral trough, the premaxillaries are in contact to their anterior ends. In front of the anterior end of the vomer (USNM 23022; length, 785 mm.), which terminates 310 mm. behind the extremity of the right premaxillary of this skull the opposite maxillaries do not meet on the midline to contribute the bottom of the me- sorostral trough. The internal surface of each premax- illary, however, is concavely curved downward to form the dorsal portion of the lateral wall of the mesorostral trough. Each premaxillary (USNM 16570) attains its maximum width (45 mm.) at the level of the anterior ends of the corresponding maxillary. The posterior ascending portion of each premaxillary rests in a narrow groove on the dorsointernal border of the adjacent maxillary and is lodged at the hinder end in the narrow grooves on the dorsal surface of the frontal. Dorsally, each relatively thin pre- maxillary is narrowed alongside the nasals. On each side the premaxillary follows the curvature of the nasal fossa and then progressively increases in depth and width. On the anterior three fourths (600± mm.) of the length of the rostrum (800 ± mm.) the dorsal surfaces of the premax- illaries are noticeably flattened. Poorly preserved nasal bones are present on two skulls (USNM 10677, 16119); they are detached and lost from all other skulls of this species in the collection. On the above-mentioned skulls, the grooves for sutural contact on the frontals and the in- terval between the posterior ends of the opposite premax- illaries also indicate th
Size: 983px × 2544px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
