Echinoderm Faunas of the Hongguleleng Formation, Late Devonian (Famennian), Xinjiang-Uygur Autonomous Region, People's Republic of China

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 includeJunggaroblastus hoxtolgayensisnew genus and species,Orophocrinus devonicusnew species,Xinjiangoblastus ornatusnew genus and species,Uyguroblastus conicusnew genus and species,Sinopetaloblastus jinxingaenew genus and species, andHouiblastus devonicusnew genus and species. Crinoid taxa includeUperocrinus zhaoaenew species, ?Hexacrinitesspecies,Agathocrinus junggarensisnew species,Chinacrinus xinjiangensisnew genus and species, ?C.nodosusnew genus and species,C.species A, C. species B,C.species C,Eutaxocrinus chinaensisnew species,E. boulongourensisnew species,E. basellusnew species,Forbesiocrinus inexpectansnew species,Deltacrinus asiaticusnew species,Bridgerocrinus minutusnew species,B. delicatulusnew species,Cosmetocrinus parvusnew species, ?Pachylocrinus subpentagonalisnew species,“Decadocrinus” constrictusnew species, “D.”elongatusnew species, “D.”rugosusnew species, “D.”usitatusnew species, “D.”xinjiangensisnew species, ?Graphiocrinusspecies,Holcocrinus asiaticusnew 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.