Annals of the South African MuseumThe Museum, 1991 - Natural history |
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Page 9
... 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 length , and is ornamented with radial rows of fine ...
... 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 length , and is ornamented with radial rows of fine ...
Page 33
... 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 prominent ...
... 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 prominent ...
Page 39
... respiratory margin rounded . The escutcheon is broad , deeply sunken , lanceolate , with weak oblique costellae along its outer margin , the inner margin being smooth . In some individuals the escutcheon is entirely ribbed or entirely ...
... respiratory margin rounded . The escutcheon is broad , deeply sunken , lanceolate , with weak oblique costellae along its outer margin , the inner margin being smooth . In some individuals the escutcheon is entirely ribbed or entirely ...
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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