Fig. 9

Roveacrinus pyramidalis Peck, upper Duck Creek Formation, Mortoniceras rostratum Zone (upper Albian); Saginaw Quarry, Fort Worth, Texas. Ontogenetic series of cups. a Aboral view, apex partly damaged, M11596. b Aboral view with two weak radial spines, apex not preserved, M11594. c Aboral view of cup with one radial spine, apex not preserved, M11585. d Aboral view of cup with long radial spine, apex not preserved, M11595. e Aboral view of cup with intact apex and five unequal radial spines, M11586. f Lateral view, radial processes moderately produced, M11590. g Lateral view of conical cup with one prominent radial process, interfacet processes unequal; 11591. h Lateral view of cup with high interfacet processes, radial processes moderately produced; M11592. i. Lateral view of cup with low interfacet processes, radial processes well-produced; M11589. j Lateral view of cup with high interfacet processes, radial processes unequal; M11587. k Lateral view of cup with single high interfacet process, radial processes projecting wide cup; M11593