|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Strophomenata - Strophomenida - Leptestiidae
|G. A. Cooper 1956||Shells small, concavo-convex, with the pedicle valve tumid ; cardinal extremities auriculate ; anterior commissure sulcate ; surface multicostellate ; a few strong costellae standing out in a field of very fine costellae.
Pedicle valve with deeply impressed large muscle field ; diductor scars elongate, divergent; adductor field oval in outline, deeply impressed, separating the posterior ends of the diductors. Teeth thick ; dental plates stout ; umbonal cavities filled by callus; dental plates extended as stout ridges around outside margin of muscle field. Vascula media short and thick, bifurcating into a larger inner branch and a small, shorter outer branch. Interarea curved, longer than the one on the brachial valve, hypercline. Pseudodeltidium short.
Brachial interior with strongly bilobed visceral disk, lobes triangular to rounded and the seat of attachment of the adductor muscles. Lobes with elevated rims on inside ; rims extending nearly to cardinal process. Lobes separated by a high, thin median septum extending to about the middle. Brachial processes short and small ; cardinal process with short, stout shaft bearing 3 ridges on the myophore face, a median elevated ridge and lateral lower ridges.
|A. A. Madison 2017||Shell strongly concavoconvex, subtriangular in outline, with maximum width at posterior margin. Ornamentation consists of ribs of two orders. Pseudodeltidium rudimentary or absent; chilidium present; teeth large and doubled; dental plates long; denticles along posterior margin may be developed. Muscle field of ventral valve consists of large, deeply impressed and well bordered diductor scars; adductor scars may be absent in some species; wide septum composed of fused tubercles may present. Cardinal process high, cleft, with trifid myophore; bema with undercut anterior margin, divided into two parts, with septum in the middle. Platform (or diaphragm) variously developed.|