Decadocrinus

Abstract: Famennian (Late Devonian) echinoderm faunas are poorly known on a global basis, although reasonably diverse faunas have been reported from England and Germany. We have collected a diverse (>500 specimens representing approximately 30 taxa) Famennian echinoderm fauna dominated by blastoids and inadunate, small-calyx camerate, and flexible crinoids from the Hongguleleng Formation, Junggar Basin, Xinjiang–Uygur Autonomous Region, People's Republic of China. Taxa reported here include five new genera and six new species of blastoids along with one new genus and 19 new species of crinoids. Blastoid taxa include Junggaroblastus hoxtolgayensis new genus and species, Orophocrinus devonicus new species, Xinjiangoblastus ornatus new genus and species, Uyguroblastus conicus new genus and species, Sinopetaloblastus jinxingae new genus and species, and Houiblastus devonicus new genus and species. Crinoid taxa include Uperocrinus zhaoae new species, ?Hexacrinites species, Agathocrinus junggarensis new species, Chinacrinus xinjiangensis new genus and species, ?C. nodosus new genus and species, C. species A, C. species B, C. species C, Eutaxocrinus chinaensis new species, E. boulongourensis new species, E. basellus new species, Forbesiocrinus inexpectans new species, Deltacrinus asiaticus new species, Bridgerocrinus minutus new species, B. delicatulus new species, Cosmetocrinus parvus new species, ?Pachylocrinus subpentagonalis new species, “Decadocrinus” constrictus new species, “D.” elongatus new species, “D.” rugosus new species, “D.” usitatus new species, “D.” xinjiangensis new species, ?Graphiocrinus species, Holcocrinus asiaticus new species, and four species of inadunate crinoids that could not be assigned to genera. This fauna is more abundant and diverse than all other Famennian echinoderm faunas in the world combined, and it is critical in understanding echinoderm biogeography and evolution in the aftermath of the Late Devonian extinction event(s) prior to the Carboniferous echinoderm diversification. This echinoderm fauna is “Carboniferous” in affinity and indicates that echinoderm diversification and reradiation were well underway before the close of the Famennian.