|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Nothorthis tarda lata
Rhynchonellata - Orthida - Archaeorthidae
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||Subrectangular, unequally biconvex Nothorthis with a subcarinate pedicle valve just over one-third as deep as wide and a gently convex, broadly sulcate brachial valve just over three-fifths as long as wide; costellate ornamentation fine, commonly with 6 angular costellae per millimetre antero-medianly; teeth small, supported by receding dental lamellae, ventral muscle-scar squat, no more than three-fifths as long as wide and extending anteriorly for just over one-fifth the length of the pedicle valve, adductor scar very broad; notothyrial platform and brachiophore bases well developed, cardinal process absent or represented by an indistinct septum on the notothyrial floor, adductor scars reniform, strongly inlpressed and extending forward on either side of a wide median ridge for just over one-half the length of the valve.|