Fig. 2 in Pyritized tube feet in a protasterid ophiuroid from the Upper Ordovician of Kentucky, U.S.A.

Fig. 2. Protasterina flexuosa (Miller and Dyer, 1878), Edenian (Upper Ordovician) near Covington, Kentucky. ESEM photographs of pyritized tube feet, CMC 25001. A. Broken tube foot preserved in arm outside the disk. B. Close−up of outside surface of tube foot showing subhedral and euhedral crystals; note euhedral octahedra (arrows). C. Close−up of broken cross−section of same tube foot. D. Buccal tentacle inside mouth frame (bt); view is from the axis of the arm into the mouth area; proximal ambulacrals visible at bottom (a); concave mouth angle ossicles (mao) at upper right; mouth angle ossicles with possible spine bearing ridge in upper left (s).