Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . riorly produced, with subterminal umbones;marginal and inner carinae prominently nodate, generally persisting to maturity; 10 ANNALS OF THE SOUTH AFRICAN MUSEUM area broad, typically with transverse ornament and longitudinal groove oftenmarked by row of nodes; respiratory margin generally broadly truncate; escut-cheon smooth, nodate, or with transverse ornament; flank ribs primitivelysubconcentric and entire but mostly strongly oblique and nodate, in derivedforms may form chevrons. Discussion This superfamily comprises t
Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . riorly produced, with subterminal umbones;marginal and inner carinae prominently nodate, generally persisting to maturity; 10 ANNALS OF THE SOUTH AFRICAN MUSEUM area broad, typically with transverse ornament and longitudinal groove oftenmarked by row of nodes; respiratory margin generally broadly truncate; escut-cheon smooth, nodate, or with transverse ornament; flank ribs primitivelysubconcentric and entire but mostly strongly oblique and nodate, in derivedforms may form chevrons. Discussion This superfamily comprises the families Frenguelliellidae (Frenguelliellinaeand Laevitrigoniinae) with subconcentric, more or less entire, flank costation,Myophorellidae (Myophorellinae and Steinmanellinae subfam. nov.) withobliquely nodate flank costation, and the derived Vaugoniidae (Vaugoniinaeand Quadratotrigoniinae) with nodate, V-shaped flank costae. The Frenguelliel-linae (Fig. 4) preserve the primitive condition of subconcentric flank costae and re c 1o ao >2 (/) re c Eoo> 3 re >. Fig. 4. Hypothesized relationships within the Myophorellacea. Character states: 1 = flankcostae subconcentric, beaded inner and marginal carinae which persist to maturity, escutcheonsmooth, area with fine transverse ornament; 2 = antecarinal sulcus virtually obsolete, nodoseflank costae oblique, escutcheon sometimes with transverse costellae, longitudinal furrow toarea often delimited by row of nodes; 3 = flank costae form chevrons near umbo; 4 = large,massive, carinae breaking up into rows of nodes or becoming obsolete in maturity, area oftenwith transverse growth rugae in maturity; 5 = large, massive, carinae replaced by prominentnodes, longitudinal furrow delimited by prominent nodes, escutcheon with radial rows ofnodes, area with transverse growth rugae in maturity, comprises Quadratotrigonia homoeo-morphs; 6 = shell ovate, very broad antecarinal sulcus shallow and unornamented, weakirregular flank costae co
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Keywords: ., bookauthorsouthafr, bookcentury1800, bookdecade1890, bookyear1898
