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Leptaena (Septomena) alaskensis

Strophomenata - Strophomenida - Rafinesquinidae

Taxonomy
Leptaena (Septomena) alaskensis was named by Rasmussen et al. (2012). Its type specimen is MGUH 29456 and is a 3D body fossil. Its type locality is Locality A-1230 Blocks 4-6, which is in an Ashbyan deep subtidal ramp limestone/siltstone in the Telsitna Formation of Alaska.

Sister species lacking formal opinion data

View classification of included taxa

Synonymy list
YearName and author
2012Leptaena (Septomena) alaskensis Rasmussen et al. pp. 15 - 16 figs. Plate 1, figures 20–23

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Eutriploblastica
Neotriploblastica
Eucoelomata
superphylumLophotrochozoa
Lophophorata
phylumBrachiopodaCuvier 1805
subphylumRhynchonelliformeaWilliams et al. 1996
RankNameAuthor
classStrophomenataWilliams et al 1996
orderStrophomenidaOpik 1934
superfamilyStrophomenoideaKing 1846
familyRafinesquinidaeSchuchert 1893
subfamilyLeptaeninaeHall and Clarke 1894
genusLeptaenaDalman 1828
subgenusSeptomena(Roomusoks 1989)
speciesalaskensis

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
C. M. O. Rasmussen et al. 2012Shell medium to large, plano-convex, subquardrate to slightly bilobate in outline; shell sharply geniculate dorsally. Maximum width at mid-valve. Anterior commissure uniplicate, sharply geniculate dorsally. Ventral interarea wide and high. Ornament of closely spaced parvicostellate intersected by larger costellae and concentric rugae. Dorsal interior with brachiophores flat and wide. Cardinal process bifid and undercut. Median septum weak with two pairs of transmuscle ridges. Inner pair subparallel, outer pair divergent, shorter, but more pronounced.