. Bulletin of the British Museum (Natural History), Geology. MAASTRICHTIAN AMMONITES below the Loftusia-rich beds at Jebel Huwayyah, section 1. Superfamily ACANTHOCERATACEAE de Grossouvre, 1894 Family SPHENODISCIDAE Hyatt, 1900 (= Libycoceratidae Zaborski, 1982: 306) Genus LIBYCOCERAS Hyatt, 1900 TYPE species. Sphenodiscus ismaelis Zittel, 1895, p. 451, text-fig. 631, by original designation. Libycoceras ? sp. Plate 2, figs 17-19 Description. BMNH C93887 is a very corroded internal mould of a small adult with 240° of body chamber preserved and a maximum diameter of 80 mm. The phragmocone is ox
. Bulletin of the British Museum (Natural History), Geology. MAASTRICHTIAN AMMONITES below the Loftusia-rich beds at Jebel Huwayyah, section 1. Superfamily ACANTHOCERATACEAE de Grossouvre, 1894 Family SPHENODISCIDAE Hyatt, 1900 (= Libycoceratidae Zaborski, 1982: 306) Genus LIBYCOCERAS Hyatt, 1900 TYPE species. Sphenodiscus ismaelis Zittel, 1895, p. 451, text-fig. 631, by original designation. Libycoceras ? sp. Plate 2, figs 17-19 Description. BMNH C93887 is a very corroded internal mould of a small adult with 240° of body chamber preserved and a maximum diameter of 80 mm. The phragmocone is oxycone, with a whorl breadth to height ratio of 0-4. The body chamber develops subparallel flanks, and the venter rounds progressively; the whorl breadth to height ratio is 0-39 at the aperture. No ornament is preserved on the heavily corroded surface, other than a faint trace of low ribs on the outer flank. The suture (Text-fig. 1) shows a well-developed adventitious lobe in the first lateral saddle, the ventral saddles are feebly indented, and the umbilical saddle is entire. Discussion. This poorly preserved specimen is referred to Libycoceras? rather than Sphenodiscus on the basis of its sutural characteristics; it is specifically indeterminate. Occurrence. BMNH C93887 is from the basal conglomer- atic bed of the Simsima Formation at Jebel Buhays, section 2. Species of Libycoceras first occur in the Upper Campanian and may range into the Lower Maastrichtian (Zaborski 1982). Suborder ANCYLOCERATINA Wiedmann, 1966 Superfamily TURRILITACEAE Gill, 1871 Family DIPLOMOCERATIDAE Spath, 1926 (= Neocrioceratinae Spath, 1953) Subfamily DIPLOMOCERATINAE Spath, 1926 (= Scalaritinae Ward, 1976: 455) Genus GLYPTOXOCERAS Spath, 1925 (= Neohamites Brunnschweiler, 1966) Type species. Hamites rugatus Forbes, 1846: 116, pi. 11, fig. 6, by original designation (Spath 1925: 30, as Hamites (Aniso- ceras) rugatus (Forbes) Kossmat).. 10mm Fig. 1 Idealised suture of Libycoceras'? sp., based on BMNH
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