|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Orthida - Platystrophiidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|A. Williams 1962||Transversely quadrate Platystrophia with a flat-bottomed ventral sulcus over half as wide as the length of the pedicle valve and a complementary dorsal fold bearing a pair of primary submedian costae each of which bifurcates at about 5 mm. from the umbo, flanks of fold and sulcus ornamented by 16-20 sharp-crested costae with a wave-length of just over 1 mm.; teeth small, dental lamellae long and subparallel forming lateral boundaries to a muscle-field, almost twice as long as wide, which is deeply impressed on an elevated tongue of secondary shell substance; supporting plates to brachiophores short, convergent onto a small, poorly developed notothyrial platform, dorsal adductor scars lightly impressed, about two-fifths as long as the valve.|