|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Protorthida - Skenidiidae
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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.
|F. R. C. Reed 1917||Shell small, transversely triangular to semielliptical, sharply folded down middle line ; hinge-line equal to width of shell; cardinal angles subacute to rectangular. Pedicle-valve deeply conical, strongly carinate, with dependent lateral lobes making a wide angle ; hinge-area large, triangular, nearly at right angles to plane of valve ; beak small, prominent, forming apex of cone, pointed, elevated, and slightly incurved. Brachial valve bilobed by deep angulated median sinus increasing in width anteriorly, with gently convex lateral lobes; anterior margin more or less emarginate in middle; beak inconspicuous; hinge-area narrow; interior with long linear cardinal process, median septum about half the length of valve, and pair of short converging plates uniting with septum and forming spondylium. Surface of valves covered with 30-40 simple straight subangular closely placed regular equal fine ribs; concentric striae very faint or absent.|
|A. Williams 1962||Large, subpentagonal Skenidioides with a pyramidal pedicle valve about four-fifths as long as wide and one-half as deep as long, sloping away from a long, curved apsacline interarea and a gently convex brachial valve, sulcate posteriorly and projecting as a broad rounded tongue antero-ventrally; ventral umbo commonly asymmetrical; radial ornamentation typically costate, but developing late costellae, with 23 to over 30 ribs on the pedicle valve, including a median fascicle comprising 3-8 costellae; spondylium supported by median ridge extending forward of the ventral umbo for about one-fifth the length of the valve; vascula media thin, divergent; dorsal median septum extending anteriorly for about threequarters the length of the brachial valve and only slightly longer than a pair of semi-elliptical adductor scars impressed on either side.|