Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . Fig, 96. A. Texanites collignoni sp. nov. Whorl section of paratype SAS-Z1755. B. Uncorrected sketches of whorl section of Texanites oliveti (Blanckenhorn, 1905) from Israel, x 0,5. CRETACEOUS FAUNAS FROM SOUTH AFRICA 129 the dorsal third of the flanks, coinciding with the position of the lateral tubercle. None of the specimens has the innermost whorls preserved, and the earliestwhorls preserved already show pentatuberculate ornament. Typical ornament, as shown by SAS-Z866 (Fig. 97) and SAM-PCZ5920(Fig. 98), consists
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . Fig, 96. A. Texanites collignoni sp. nov. Whorl section of paratype SAS-Z1755. B. Uncorrected sketches of whorl section of Texanites oliveti (Blanckenhorn, 1905) from Israel, x 0,5. CRETACEOUS FAUNAS FROM SOUTH AFRICA 129 the dorsal third of the flanks, coinciding with the position of the lateral tubercle. None of the specimens has the innermost whorls preserved, and the earliestwhorls preserved already show pentatuberculate ornament. Typical ornament, as shown by SAS-Z866 (Fig. 97) and SAM-PCZ5920(Fig. 98), consists of radial to slightly rursiradiate single ribs, each bearing arounded to radially elongated umbilical (1) tubercle, displaced slightly ventrally. Fig. 97. Texanites collignoni sp. nov. Paratype SAS-Z866. x 0,58. 130 ANNALS OF THE SOUTH AFRICAN MUSEUM from the umbilical edge, a prominent radially elongated, lateral (2) tubercletowards the dorsal third of the flanks (this tubercle juts out furthest laterallythough it is not necessarily strongest developed), and progressively clavatesubmarginal (3), marginal (4) and external (5) tubercles over the rest of theflanks. With increasing diameter, and especially towards the body chamber,the umbilical and the lateral tubercles move ventrally, so that the former issome distance from the umbilical region and the latter nearer midflank. Intypical forms ribbing is single, but some specimens feature bifurcations. Thekeel is undulating; undulations coinciding with lateral ornament.
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Keywords: ., bookcentury1800, bookdecade1890, booki, booksubjectnaturalhistory
