Devonian cladid crinoids: Families Glossocrinidae Goldring, 1923, and Rutkowskicrinidae new family

The cladid crinoid order Poteriocrinida Jaekel, 1918 is a polyphyletic grou p that includes a variety of independent lineages united solely by the pres ence of ramulate or pinnulate arms. One of these linea les is the Rutkowski crinidae new family herein assigned to the order Dendrocrinida. Bather 1899 . Genera assigned to this new family include Rutkowskicrinus new genus, Dec orocrinus new genus, Iteacrinus, Nassoviocrinus, Quantoxocrinus, Sacrinus, Sostronocrinus, ?Propoteriocrinus, and ?Schmidtocrinus. Members of this fam ily are characterized by low conical cups with ridged thecal plates, U-shap ed peneplenary radial facets bearing faint transverse ridges, a proximal me dian ridge on the posterior side of a long, narrow, predominantly straight anal sac, and pentagonal columns with one to two cirri per nodal. Arms in t his family are highly variable, ranging from isotomous to heterotomous and pinnulate. The arms in the type specimen of Rutkowskicrinus patriciae n. sp . preserve all these various arm stages. The oldest presently known rutkows kicrinids occur in the Late Silurian (Ludlovian) of Australia and the Early Devonian (Pragian) of western Europe. The family diversified during the Mi ddle Devonian (Givetian) in northeastern North America, and declined in num bers and diversity throughout the Late Devonian before going extinct in the Early Mississippian (Tournaisian). The Glossocrinidae Goldring. 1923, containing Glossocrinus, Charientocrinus , Catactocrinus, and Liparocrintis, is also reviewed. This family, distingu ished by a strongly recumbent anal sac in the B-E plane and a prominent med ian ridge extending the entire length of the anal sac, was derived from the Rutkowskicrinidae during the Middle Devonian (Givetian) and diversified in the Late Devonian before going extinct at the Frasnian-Famennian boundary, The previously described rutkowskicrinid and glossocrinid genera listed abo ve were assigned by Moore et al. (1978) to the dendrocrinid family Mastigoc rinidae and poteriocrinid families Rhenocrinidae, Poteriocrinitidae, and Sc ytalocrinidae. Studied taxa include Rutkowskicrinus patriciae new genus and species, Rutkowskicrinus collieri new genus and species, Nassoviocrinus co status (Goldring, 1954) new combination, Nassoviocrinus schultzei (Haarmann , 1921) new combination, Nassoviocrinus? duluki (Kesling, 1969) new combina tion, Nassoviocrinus? ornatus (Goldring, 1954) new combination, Nassoviocri nus? chilmanae new species, Decorocrinus arkonensis (Goldring, 1950) new co mbination, Decorocrinus cooperi (Goldring, 1926) new combination, Quantoxoc rinus clarkei (Williams, 1882) new combination, Glossocrinus halli (Goldrin g, 1923) new combination, and Charientocrinus bellitubatus (Kesling, 1973) new combination.