|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Rhynchonellida - Rhynchotrematidae
It was recombined as Hiscobeccus gigas by Amsden (1983) and Rasmussen (2013).
Is something missing? Join the Paleobiology Database and enter the data
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.
|C. M. O. Rasmussen 2013||Medium to large, sub-circular shell, with maximum width between mid-valve and anterior third of valve length. Dorsi-biconvex, unisulcate. Ornament of simple, sub-rounded and relatively low costae, numbering to approximately 18. Dorsal fold with four costae and ventral sulcus with three costae. Entire shell lamellose. Ventral valve weakly convex with pronounced sulcus, forming truncated, tongue-like structure. Dorsal valve moderately convex with moderately elevated fold, and seven to eight costae on each side of the fold. Ventral valve possesses a high, curved palintrope which extends posteriorly as an incurved beak. Delthyrium low, wide. Dorsal beak strongly incurved and, thus, hidden in the ventral delthyrium. Seen laterally the commissural plane bends ventrally at a characteristic obtuse angle just anterior to the umbonal zone. Interiors not examined. Dorsal interior possibly with median septum.|