Basic info Taxonomic history Classification Relationships
Morphology Ecology and taphonomy External Literature Search Age range and collections

Strophomena imbrex semiglobosina

Strophomenata - Strophomenida - Rafinesquinidae

Taxonomy
Strophomena imbrex semiglobosina was named by Davidson (1870).

It was recombined as Rafinesquina (Playfairia) semiglobosina by Reed (1917); it was recombined as Dactylogonia semiglobosina by Williams (1962) and Candela and Harper (2014).

Synonymy list
YearName and author
1870Strophomena imbrex semiglobosina Davidson figs. pl. xli, figs. 5, 6, non figs. 1-4
1883Strophomena imbrex semiglobosina Davidson p. 195 figs. pl. xv, fig. 11, non figs. 9, 10.
1917Rafinesquina (Playfairia) semiglobosina Reed pp. 869 - 870 figs. pl. xii, figs. 14, 16--20, non figs. 13, 15.
1962Dactylogonia semiglobosina Williams pp. 201 - 202 figs. Pl. XIX, figs. 24-26; P1. XX, figs. 1, 2, 5
2014Dactylogonia semiglobosina Candela and Harper pp. Supplement 1

Is something missing? Join the Paleobiology Database and enter the data

RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Protostomia
Spiralia
superphylumLophotrochozoa
Lophophorata
phylumBrachiopodaCuvier 1805
subphylumRhynchonelliformeaWilliams et al. 1996
RankNameAuthor
classStrophomenataWilliams et al 1996
orderStrophomenidaOpik 1934
superfamilyStrophomenoideaKing 1846
familyRafinesquinidaeSchuchert 1893
subfamilyRafinesquininaeSchuchert 1893
genusStrophomenaWang 1949
speciesimbrex(Billings 1862)
subspeciessemiglobosinaDavidson 1870

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.

Diagnosis
ReferenceDiagnosis
F. R. C. Reed 1917Shell subquadrate to semielliptical, strongly concavo-convex; valves closely appressed, sometimes subauriculate; hinge-line equal to (rarely less than) maximum width of shell; cardinal angles usually rectangular. Pedicle-valve swollen, moderately to strongly convex, not geniculated but regularly arched; lateral angles sometimes flattened; beak small, not much incurved; hinge-area triangular, rather narrow, steeply inclined to plane of valve, with triangular delthyrium. Interior of pedicle-valve with small subcircular forked muscle-scar, well defined at sides, less than one-fourth the length of valve, composed of two flabellate diductors divergent anteriorly, with narrow elongate adductor scar between them; teeth small. Brachial valve regularly concave, with inconspicuous beak and narrow hinge-area nearly at right angles to plane of valve. Interior of brachial valve with strong submarginal thickening coarsely corrugated radially; cardinal process large, thick, prominent, bilobed, deeply cleft to base, with grooved subtriangular face to each lobe; crural plates stout, thickened, continued round posterior adductors; muscle-scars deeply sunk; posterior adductors transverse, subcircular; anterior adductors elongate, forming much narrower less-defined scar in front. Ovarian areas closely pitted. Shell finely punctate. Surface of shell covered with 30-50 primary thread-like regular equidistant equal riblets, with usually a secondary one arising in each interspace at half their length midway between them; primaries and secondaries all equal in strength and equidistant on margin; 3-7 much finer radial lines in each interspace between primaries and secondaries; short concentric corrugations near hinge-line sometimes present.