Annals of the South African MuseumThe Museum, 1991 - Natural history |
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Page 9
... lanceolate , slightly more than half the shell length , and is ornamented with radial rows of fine tubercles that , on D1876 , curve inward to meet the commissure . The trigonal area is relatively narrow and almost flat . It is ...
... lanceolate , slightly more than half the shell length , and is ornamented with radial rows of fine tubercles that , on D1876 , curve inward to meet the commissure . The trigonal area is relatively narrow and almost flat . It is ...
Page 13
... lanceolate , smooth , and extends almost the entire posterodorsal length of the shell . The marginal and escutcheon carinae are marked by rows of large , regular , obliquely clavate tubercles that increase in size posteriorly ; those of ...
... lanceolate , smooth , and extends almost the entire posterodorsal length of the shell . The marginal and escutcheon carinae are marked by rows of large , regular , obliquely clavate tubercles that increase in size posteriorly ; those of ...
Page 17
... lanceolate , and ornamented with irregular rows of bullae that follow the growth lines and are continuous with the growth rugae of the area . There is a narrow lunule , about one - third of the shell height . The ligament pit is well ...
... lanceolate , and ornamented with irregular rows of bullae that follow the growth lines and are continuous with the growth rugae of the area . There is a narrow lunule , about one - third of the shell height . The ligament pit is well ...
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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