Mississippian crinoid fauna from the Banff Formation, Sunwapta Pass, Alberta
40
Citation
4
Reference
20
Related Paper
Citation Trend
Keywords:
Crinoid
Cite
Cite
Citations (42)
Cite
Citations (25)
Late Osagean to Meramecian Platycrinites and Eucladocrinus from Illinois, Iowa, and Missouri are redescribed and redefined from study of type material. Three of the oldest species were incorrectly synonymized with P. sarae , and this correction leads to a realignment of species systematics within Platycrinites. Accordingly, six species of Platycrinites and one species of Eucladocrinus are considered valid in the Keokuk Limestone through St. Louis Limestone of the stratotype area. Valid species include Platycrinites saffordi (Hall), P. sarae (Hall), P. georgii (Hall), P. pumilus (Hall), P. brevinodus (Hall), P. niotensis (Meek and Worthen), and Eucladocrinus millebrachiatus Wahsmuth and Springer. Nomenclatoral changes include the following: 1) P. sarae is redescribed and all junior synonyms are removed; 2) P. georgii is a valid senior synonym of P. bonoensis (White), P. aeternalis (Miller), P. boonvillensis (Miller), and P. cauducus ; 3) P. pentagonus (Miller) is a junior synonym of P. niotensis ; 4) P. pumilus is a valid senior synonym of P. prattenanus (Meek and Worthen), and P. monroensis (Worthen); 5) P. bloomfieldensis (Miller) is designated as a nomen dubium; and 6) Eucladocrinus millebrachiatus immaturus is a junior synonym of E. millebrachiatus. The evoluton of new species in Platycrinites was by a combination of cladogenesis and possibly anagenesis. Platycrinites sarae evolved from P. saffordi possibly through anagenesis, P. pumilus evolved from P. niotensis through cladogenesis, and P. hemisphaericus evolved through cladogenesis from P. brevinodus , although P. hemisphaericus does not occur in the geographic area of this study.
Cladogenesis
Synonym (taxonomy)
Nomen dubium
Cite
Citations (181)
Crinoid
Cite
Citations (42)
Cite
Citations (29)
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.
Echinoderm
Devonian
Cite
Citations (58)
Marine invertebrates
Cite
Citations (383)
Crinoids are marine invertebrates of unsurpassed variety of form and complexity of skeletal organization. They range from Early Ordovician time to the present, but their development in kinds and numbers culminated during the Paleozoic.
Marine invertebrates
Cite
Citations (344)
SUMMARY Sixty genera of Mississippian crinoids, comprising 191 species, are evaluated from 83 localities in England and Wales, based on modern revisions from the literature, study of museum collections and new field work. These genera occurred through ten time units in the Mississippian (Tournaisian–Serpukhovian). Among the 191 species, 161 are considered valid with 28 requiring new combinations of genus and species names. Twelve species are considered nomina dubia, one species is considered a nomen nudum, three species cannot be assigned with certainty to a genus, and 14 can only be assigned at the generic level. Hastarian (Times 1 and 2) faunas have a very low generic richness with only one genus known. Ivorian (Time 3) faunas have a substantially higher generic richness with 21 genera known. Chadian faunas have the highest generic richness with 28 genera from the lower Chadian (Time 4) and 19 genera from the upper Chadian (Time 5). Post-Chadian faunas include those from the Arundian (Time 6), Holkerian (Time 7), Asbian (Time 8), Brigantian (Time 9) and Pendleian (Time 10); all have low generic richness with 0, 4, 7, 13 and 7 genera known, respectively. The dominant Mississippian crinoid faunas are on Ivorian carbonate ramps, Chadian Waulsortian and Waulsortian-related facies, and in the Pendleian marine beds that supported Woodocrinus. In comparable facies, the composition of faunas is similar in England and Wales and North America, although generic richness is commonly lower in England and Wales. The overall crinoid fauna has much lower generic richness in England and Wales than in North America because the stratigraphical record of England and Wales preserves a much lower diversity of crinoid-bearing facies. The critical Arundian-Holkerian interval for Palaeozoic crinoid history is poorly represented in England and Wales.
Cite
Citations (40)
Devonian
Cite
Citations (70)