Table 6 in Late Viséan (late Mississippian) ammonoids from the Barnett Shale, Sierra Diablo Escarpment, Culberson County, Texas, USA

Table 6. Characteristics of genera within the subfamily Dombaritinae. ChoctawitesLusitanocerasRevillocerasDombaritesGeneral shape of innersubevolute to evolutesubevoluteevolutesubinvolutewhorlsWhorl profile of inner whorlswhorls widest at some distance from umbilical margin, flanks diverging or subparallel, trapezoidalwhorls widest at umbilical margin, flanks convergingwhorls widest at umbilical margin, flanks convergingvariableConstrictionsonly on steinkernon shell surfaceon shell surfaceoften on shell surfaceCoiling of inner whorlsroundedusually triangulartriangulartriangular at some speciesOrnament in the subadult stagefine spiral linescoarse spiral linescoarse spiral linesvariableOrnament in the adult stagefine spiral lines, falcate transverse ornamentcoarse spiral lines, occasionally falcate transverse ornamentcoarse spiral lines, falcate transverse ornamentvariableHeight of median saddle0.60 of external lobe depth0.50–0.55 of external lobe depth0.50–0.55 of external lobe depth0.65–0.75 of external lobe depthShape of external lobeweakly Y-shapedweakly Y-shapedstrongly Y-shapedweakly Y-shapedWidth of external lobe0.80 of E lobe depth0.65 of E lobe depth0.70 of E lobe depth0.70–0.85 of E lobeat half depthdepthShape of external lobe prongsV-shapedV-shapedlanceolateV-shaped or lanceolateFlanks of adventive lobesinuousslightly sinuouswith inflexionwith inflexion