Annals of the South African MuseumThe Museum, 1991 - Natural history |
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Page 14
... irregular , radially elongated tubercles ; median groove to area marked by rows of coarse nodes ; area of early and middle growth stages with transverse growth striae , later remaining smooth or with coarse , irregular growth rugae ...
... irregular , radially elongated tubercles ; median groove to area marked by rows of coarse nodes ; area of early and middle growth stages with transverse growth striae , later remaining smooth or with coarse , irregular growth rugae ...
Page 15
... irregular growth rugae . The earliest genus in the subfamily is Steinmanella itself , which first occurs in Tithonian rocks of South America ( Leanza & Garate 1987 ) . Simply by failure to produce coarse irregular growth rugae across ...
... irregular growth rugae . The earliest genus in the subfamily is Steinmanella itself , which first occurs in Tithonian rocks of South America ( Leanza & Garate 1987 ) . Simply by failure to produce coarse irregular growth rugae across ...
Page 24
... irregular oblique rows of elongate tubercles that vary in size and follow the growth striae . Posteriorly these tubercles are continuous with the growth rugae of the area . There is a very narrow lunule , about 40 per cent of the shell ...
... irregular oblique rows of elongate tubercles that vary in size and follow the growth striae . Posteriorly these tubercles are continuous with the growth rugae of the area . There is a very narrow lunule , about 40 per cent of the shell ...
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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