Annals of the South African MuseumThe Museum, 1991 - Natural history |
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Page 9
... margin at right angles to the broadly convex anterior margin . The ventral margin is broadly convex and the moder- ately short respiratory margin obliquely truncate . The escutcheon is lanceolate , slightly more than half the shell ...
... margin at right angles to the broadly convex anterior margin . The ventral margin is broadly convex and the moder- ately short respiratory margin obliquely truncate . The escutcheon is lanceolate , slightly more than half the shell ...
Page 33
... anterior margin passes evenly into the almost straight ventral margin . The posterodorsal margin is broadly concave and the respiratory margin seems to have been narrowly rounded . The oval , flattened anterior face meets the flanks at ...
... anterior margin passes evenly into the almost straight ventral margin . The posterodorsal margin is broadly concave and the respiratory margin seems to have been narrowly rounded . The oval , flattened anterior face meets the flanks at ...
Page 39
... Anterior margin weakly curved to almost straight , very high , with broad , flattish anterior face , passing rather sharply into the broad , straight to slightly concave ventral margin . The posterodorsal margin is deeply concave and ...
... Anterior margin weakly curved to almost straight , very high , with broad , flattish anterior face , passing rather sharply into the broad , straight to slightly concave ventral margin . The posterodorsal margin is deeply concave and ...
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Common terms and phrases
Algoa Basin Anditrigonia antecarinal sulcus anterior commissure anterolateral shoulder anteroventrally Apiotrigoniinae Bivalvia broad chevrons coarse commissure comprises convex Cooper Cretaceous Description Shell Diagnosis elongate escutcheon carina faunas finely crenulated flank costae flank ornament genus growth rugae growth striae Hauterivian Hoepen holotype inflated anteriorly interspaces Iotrigonia irregular Kobayashi kraussi Kitchin lanceolate large maximum length Lateral view lectotype left valve longitudinal groove Megatrigoniacea moderately Myophorella Myophoriidae Nakano neotype nepionic stages Neumayr nodate Nototrigoniinae opisthogyrous beaks Paranditrigonia paratypes persisting to maturity phyletic Port Elizabeth Museum posterior set posterodorsal margin Poulton Pterotrigonia radial costellae radial ornament Rennie respiratory margin Reyes ribs right valve rostrate shallowly concave shell length Skwarko smooth South African Museum Steinmanella herzogi Goldfuss straight strongly oblique subconcentric subfamily Sundays River Superfamily synonymy Tashiro Tithonian transverse costellae transverse ornament Trigonia Trigoniacea Trigoniinae trigonioid tubercles Type species Upper Valanginian V-shaped Valanginian vau Sharpe ventral margin ventricosa Krauss Yaadia