Cupitheca hemicyclata ( Bengtson, 1990b )

Malinky, John M. & Skovsted, Christian B., 2004, Hyoliths and small shelly fossils from the Lower Cambrian of North-East Greenland, Acta Palaeontologica Polonica 49 (4), pp. 551-578 : 569

Cupitheca hemicyclata ( Bengtson, 1990b)

Fig. 11 .

Actinotheca hemicyclata Bengtson, 1990b: 210 , fig. 140.

Holotype: South Australian Museum , Adelaide SAMP30864 .

Material.— MGUH 27112–27113 from GGU sample 314835.

Description.—Slightly cyrtoconic tubular conch with circular cross−section with the apex terminating in a poorly developed convex inflated septum. Side of conch toward which apex bends possesses coarse annular half rings; rings have steeply dipping sides and stand high; spaces between half rings have concave surfaces, and width of spaces equal is to about 2–3 times the width of one ring. Opposite side of conch smooth due to disappearance of co−marginal ornament about midway between opposing sides of the conch.

Remarks.—This species is represented by two fragmentary individuals in the Greenland collections, although the distinctive half rings confirm the specific identity. It is referred to Cupitheca hemicyclata based on the annular rings are seen on only one side of the conch. In C. holocyclata the rings encircle the conch.

Stratigraphic range and distribution.—Lower Cambrian, Australia and North−East Greenland.

Figures

Fig. 11. Cupitheca hemicyclata (Bengtson, 1990b). A. MGUH 27112. B. MGUH 27113. Both specimens from GGU sample 314835. Scale bars 0.2 mm.