Annals of the South African MuseumThe Museum, 1991 - Natural history |
From inside the book
Results 1-3 of 5
Page 9
... relatively narrow and almost flat . It is ornamented by finely beaded radial costellae , one of which corresponds to the escutcheon carina . There is no median groove to the area . The marginal carina is marked by a prominent rib that ...
... relatively narrow and almost flat . It is ornamented by finely beaded radial costellae , one of which corresponds to the escutcheon carina . There is no median groove to the area . The marginal carina is marked by a prominent rib that ...
Page 12
... relatively broad , with or without nodes demar- cating the longitudinal furrow ; marginal carina persisting to maturity ; flank costae evenly curved , nodes predominating , without greatly enlarged nodes or intercalatories anteriorly ...
... relatively broad , with or without nodes demar- cating the longitudinal furrow ; marginal carina persisting to maturity ; flank costae evenly curved , nodes predominating , without greatly enlarged nodes or intercalatories anteriorly ...
Page 26
... relatively small size , weak inflation , V - shaped flank costae and transversely costellate escutcheon . On the other hand , Columbitrigonia is strongly reminiscent of Megatrigonia in its large , robust shell , oblique flank costae ...
... relatively small size , weak inflation , V - shaped flank costae and transversely costellate escutcheon . On the other hand , Columbitrigonia is strongly reminiscent of Megatrigonia in its large , robust shell , oblique flank costae ...
Other editions - View all
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