Fig. 13

Primibrachials tentatively assigned to Orthogonocrinus apertus Peck (b–c, e–h) and Roveacrinus peracutus (Peck) (a, d), upper Duck Creek Formation, Mortoniceras rostratum Zone (upper Albian); Saginaw Quarry, Fort Worth, Texas. a Aboral-distal view of first primibrachial lacking distinct bowl, M11645 (this specimen is also figured in Fig. 7l under Poecilocrinus latealatus). b Adoral-proximal view of first primibrachial with facet to radial, M11638. c Adoral-proximal view of first primibrachial with facet to radial, M11640. d Adoral-proximal view of first primibrachial with rows of pits, M11642. e Aboral-distal view of first primibrachial with corrugated edges, M11637. f Adoral view of second primibrachial, M11630. g Aboral view of second primibrachial lacking bowl, M11680. g Aboral view of second primibrachial lacking bowl, M11631