Systematics and mode of life of a new Silurian Clisospira (Mollusca) from North Greenland

Abstract

Clisospira ellitsgaardi sp. nov. is described from the Cape Schuchert Formation (Early Silurian) of Washington Land, western North Greenland. The cancellate ornamentation of the sinistrally coiled molluscan shell is produced by the interference of successive crenulate growth lamellae. The wide frill of C. ellitsgaardi may have hindered sinking into soft bottom sediment or increased shell stability by increasing the surface area of the underside of the shell. The strongly tangential aperture probably indicates that C. ellitsgaardi effectively clamped its shell against the substratum when disturbed.