Stauroacanthocircus sp. A

(Fig. 10R)

OCCURRENCE. — Lower Jurassic, lower Sinemurian of Mersin Mélange, NW of Mersin city, southern Turkey.

DESCRIPTION

Shell not preserved, ring broad and elliptical. Thin ring contains eight, thin, needle-like spines. Inner cavity broad, elliptical with four thin polar spines.

REMARKS

This specimen differs from Stauroacanthocircus dickinsoni (Yeh 1989: 50, pl. 13, fig. 18) by having a broad elliptical ring and inner cavity, and thin, short peripheral and polar spines.