Fig. 7 in Crinoid ancestry without blastozoans

Fig. 7. Slat-like ambulacral floor plates of Early Ordovician echinoderms expressing podial basins, pores. A. Ambulacral details of edrioasterid Paredriophus elongatus Guensburg and Sprinkle, 1994 (PE 52740), Utah, USA. Wedge-shaped pore slits bordered by raised rims (A1); pore slits filled with syntaxial overgrowths (A2). B. Undescribed Porocrinus-like cyathocrinine cladid (NPL 1977TX12), Nevada, USA; natural break across distal?A ray arm showing cross section, floor plates, hints of podial pores, pattern similar to disparid taxon A. C. Disparid taxon A (PE 52752), Fillmore Formation, Utah, USA; specimen with intact arm and stem segments strewn over and within a limestone slab, attributed to taxon A using overlapping morphology of five other stratigraphically associated specimens. Slat-like floor plates showing wedge-shaped pores with attenuated rims, well-preserved on left, with open cover plates above (arrow) (C1); polished cross-sec- tion of arm, plates slightly ajar with dark syntaxial overgrowths, cover plates, floor plates, large coelomic space (C2). D. Cladid Apektocrinus ubaghsi Guensburg and Sprinkle, 2009 (TMM 1983TX1), Idaho, USA; B ray mid-arm segment with weathered slat-like floor plates and podial basins.