Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . tages. Flank ornament is moderately discrepant. It comprises a flexuous set ofabout 12, rather coarse, flared anterior costae that curve strongly upwards andextend to the anterior commissure. These ribs are irregularly tuberculate, with3-4 large tubercles on the anterolateral shoulder. The ten or so costae of theposterior set of ribs are finely crenulated, subparallel, narrower than the inter-spaces, and meet the posteroventral margin at right angles. Occurrence Pterotrigonia (?Pterotrigonia) knighti (Pringle) is known o
Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . tages. Flank ornament is moderately discrepant. It comprises a flexuous set ofabout 12, rather coarse, flared anterior costae that curve strongly upwards andextend to the anterior commissure. These ribs are irregularly tuberculate, with3-4 large tubercles on the anterolateral shoulder. The ten or so costae of theposterior set of ribs are finely crenulated, subparallel, narrower than the inter-spaces, and meet the posteroventral margin at right angles. Occurrence Pterotrigonia (?Pterotrigonia) knighti (Pringle) is known only from theUpper Valanginian of the Algoa Basin, where it is a very rare component of thefaunas. Pterotrigonia rogersi (Kitchin, 1908)Figs 19-20 Trigonia rogersi Kitchin, 1908: 99, pi. 3 (fig. 3), pi. 4 (fig. 1), pi. 5 (fig. 2).Pterotrigonia rogersi (Kitchin) Pringle, 1960: 89. Cooper, 1979b: 57, fig. rogersi (Kitchin) Nakano, 1965: rogersi (Kitchin) Reyes, 1970: 8, pi. 1 (figs 1-2), pi. 3 (fig. 1). 34 ANNALS OF THE SOUTH AFRICAN MUSEUM. W O J3 ©X c•C Oh, ?2c ?I ft, &0 LOWER CRETACEOUS TRIGONIOIDA FROM THE ALGOA BASIN 35 Type By lectotype designation herein, the original of the specimen figured byKitchin (1908, pi. 3 (fig. 3), pi. 4 (fig. 1)), SAM-3974 (Fig. 19C). Material A total of 108 specimens in the South African Museum, SAM-5088, 12950-53, 12955-58, 12960-62, D1882 (73 specimens) and 22 without number, as wellas PEM-1465/61. Description Shell moderately large (maximum length 135 mm), strongly inequi-lateral, moderately inflated anteriorly (W/H = 0,35-0,44), longer than high
Size: 1164px × 2147px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsouthafr, bookcentury1800, bookdecade1890, bookyear1898
