. Bulletin of the British Museum (Natural History), Geology. THE ALBERT RIFT 87 When viewed laterally, the dentigerous surface, unlike that in extant species, is not continued forwards to form a narrow ledge skirting the anterior face of the bone (Figs 11, 12). Instead, it fails to project beyond the anterior margin. The articular process in L. rhachirhinchus is larger, especially broader, than in extant species. When seen from above, it lies at an angle to the ascending process (not in the same line) and is inclined medially (not vertically as in the living species). Extant Lates and Luciolat
. Bulletin of the British Museum (Natural History), Geology. THE ALBERT RIFT 87 When viewed laterally, the dentigerous surface, unlike that in extant species, is not continued forwards to form a narrow ledge skirting the anterior face of the bone (Figs 11, 12). Instead, it fails to project beyond the anterior margin. The articular process in L. rhachirhinchus is larger, especially broader, than in extant species. When seen from above, it lies at an angle to the ascending process (not in the same line) and is inclined medially (not vertically as in the living species). Extant Lates and Luciolates have a discrete median arm extending inwards from the lateral, shield-like portion of the articular process. In L. rhachirhinchus this arm is barely represented by a low basal ridge (Fig. 12). ASCP B. ASCP Fig. 11. Premaxillae of : A. L. niloticus in left lateral view ; B. L. rhachirhinchus in right lateral view ; C. L. rhachirhinchus, anterior part of premaxilla showing ascending and articular processes, and the foramen in the latter. (Specimens figured in B and C are from paratype lot ) The stout ascending process is inclined somewhat forwards in L. rhachirhinchus, but in other species it is bowed and curves gently backwards. In all extant species, including Luciolates stappersi, the process is more slender and is separated from the articular process by a deep but narrow cleft extending almost to the bases of the two processes. Lates rhachirhinchus, in contrast, has the articular process fused to the ascending process over the greater part of its length ; a shallow notch, slightly below the tip of the articular process, is all that remains of the cleft (Fig. 11). A unique feature of the premaxilla in L. rhachirhinchus is a large foramen that opens. 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 work
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