|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Bivalvia - Protobranchia - Nuculidae
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.
|H. Morningstar 1922||Shell small, subtriangular, much produced anteriorly, length almost twice the height, greatest width slightly below the middle of the shell, gibbous in posterior portion, the greatest convexity occurring midway between the beaks and the ventral margin, shell flattened anteriorly. Umbonal region prominent, beak small, elevated and incurved over the hinge line, directed posteriorly, situated about one-fourth the length of the shell from the posterior margin; cardinal margin sloping from the beak to the extended anterior extremity; posterior extremity regularly rounded forming a continuous curve with the rounded ventral margin which anteriorly extends slightly upwaFd; anterior extremity produced and pointed. Surface of internal mold smooth except for a few faint lines of growth; occasionally indications of fine concentric lines.|