. Bulletin of the British Museum (Natural History), Geology. . 2 mm Fig. 12. Hybodus brevicostatus sp. nov. Tooth in labial (above) and lingual view. Ashdown Beds, Cliff End Bone-bed ; Cliff End, Sussex. Text-fig. 12. All these teeth are smaller than those of the holotype, with a maximum length of about lo mm., and they have fewer striae and fewer accessory cusps. In the Wadhurst Clay H. brevicostatus is represented by a fragment of a small tooth () and by (PL i, fig. 3), a large tooth, 15 mm. in length, probably a parasymphysial from the upper jaw, in which the crown is u
. Bulletin of the British Museum (Natural History), Geology. . 2 mm Fig. 12. Hybodus brevicostatus sp. nov. Tooth in labial (above) and lingual view. Ashdown Beds, Cliff End Bone-bed ; Cliff End, Sussex. Text-fig. 12. All these teeth are smaller than those of the holotype, with a maximum length of about lo mm., and they have fewer striae and fewer accessory cusps. In the Wadhurst Clay H. brevicostatus is represented by a fragment of a small tooth () and by (PL i, fig. 3), a large tooth, 15 mm. in length, probably a parasymphysial from the upper jaw, in which the crown is unusually high. In the Grinstead Clay there are thirteen teeth of H. brevicostatus among the material from the Paddockhurst bone-bed. These are all small (less than 9 mm. in length), low-crowned forms. 26027 from Tilgate Forest is a larger (11 mm.) example, again a low-crowned posterior tooth. Among the material from the Weald Clay of Henfield there is a number of teeth of H. brevicostatus in addition to the holotype. Most of these are normal teeth, as large as or a little smaller than those of the holotype, but two are very small examples (Text-fig. 13), , less than 6 mm. in length and , 4 mm. long. These small teeth agree with those of the holotype in shape and in the numerous accessory cusps, but in the few, coarse striae on the crown and in the clearly marked lateral cusps they resemble H. parvidens. One anterior tooth of H. brevicostatus () is also known from the Weald Clay of Bookhurst, Surrey. The latest occurrence of H. brevicostatus teeth is , an incomplete para- symphysial tooth from the Wealden Shales of Atherfield Point, Isle of 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). London : BM(NH)
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