Fig. 3 L, M
Triadocypris spitzbergensis Weitschat 1983 a: 309 –323, 10 figs.— 1983 b: 127–138.— Weitschat & Guhl 1994: 17 –31, figs. 1, 9. — Cohen et al. 1998: 258.— Kornicker & Sohn 2000: 22. Holotype
GeologischPaläontologisches Institut und Museum, University of Hamburg (GPIHM), no. 2558.
Type locality
Sticky Keep Formation, Lower Triassic (subrobustus Zone); Flowerdalen, Spitsbergen, lat. 78 °N, long. 17 °E (Weitschat 1983 b).
Material
No material examined herein.
Distribution
Triassic of Spitsbergen.
Diagnosis (from Weitschat 1983 b)
Myodocopid with carapace 2.9–3.1 mm long; oval in lateral view. With small rostrum and shallow rostral incisur. Posterior margin forming very slight angle at midpoint, but fairly evenly rounded. Left valve overlaps right. Delicate dentition present along dorsal margin of each valve. Ornamentation composed of small, closely spaced pits. Gills welldeveloped, with three lobes on each side. Lateral eye with about 20 ommatidia.
Foreign attachments. Weitschat & Guhl (1994: 17) described fossil ciliates attached to the body of one specimen.
Comparisons
Carapace differs from that of M. hollandica in having a shallower incisure and a different arrangement of central adductor muscle scars.
Remarks
Weitschat (1983 a: 314) referred this species to the Cypridinidae; however, the presence of five dorsal bristles on the second article of the first antenna indicates that the species belongs in the Cylindroleberididae. Weitschat (1983 a: 314) proposed a new subfamily Triadocypridininae Weitschat 1983 a for T. spitzbergensis, and Cohen et al. (1998: 254, 259) raised the status to family level as Triadocyprididae. The soft parts of T. spitzbergensis differ in some respects from those of extant Cylindroleberididae (Cohen et al. 1998: 258, 259), and the species may be a new family or subfamily. Nevertheless, the senior author believes it conservative at this time to interpret the differences as variations within the Cylindroleberididae. Several species known only from specimens without soft parts but with carapaces somewhat similar to that of T. spitzbergensis have been referred tentatively to Triadocypris.