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NARROW
GeoRef Subject
-
all geography including DSDP/ODP Sites and Legs
-
Africa
-
North Africa
-
Atlas Mountains
-
Moroccan Atlas Mountains
-
Anti-Atlas (2)
-
-
-
Morocco
-
Moroccan Atlas Mountains
-
Anti-Atlas (2)
-
-
Tafilalt (2)
-
-
-
-
Altiplano (1)
-
Arctic region (1)
-
Asia
-
Far East
-
China
-
Guizhou China (3)
-
Henan China (1)
-
Nanpanjiang Basin (1)
-
South China Block (2)
-
Xinjiang China
-
Junggar (1)
-
-
-
Korea
-
South Korea (1)
-
-
Mongolia (1)
-
-
Middle East
-
Iran
-
Elburz (1)
-
-
Turkey
-
Anatolia (1)
-
-
-
Omolon Block (1)
-
Siberia (1)
-
-
Atlantic Ocean
-
North Atlantic
-
Rockall Trough (1)
-
-
-
Canada
-
Eastern Canada
-
Newfoundland and Labrador
-
Newfoundland
-
Port au Port Peninsula (1)
-
-
-
Ontario
-
Simcoe County Ontario (1)
-
-
Quebec
-
Anticosti Island (2)
-
-
-
Nunavut
-
Ellesmere Island (1)
-
-
Queen Elizabeth Islands
-
Ellesmere Island (1)
-
-
Western Canada
-
British Columbia
-
Vancouver Island (2)
-
-
Manitoba (1)
-
Northwest Territories (1)
-
-
-
Commonwealth of Independent States
-
Russian Federation
-
Omolon Block (1)
-
-
-
Europe
-
Alps
-
Eastern Alps
-
Dolomites (1)
-
-
-
Baltic region
-
Estonia
-
Saaremaa (1)
-
-
-
Central Europe
-
Germany
-
Eifel (2)
-
Rhineland-Palatinate Germany (1)
-
-
-
Rhenish Schiefergebirge
-
Eifel (2)
-
-
Southern Europe
-
Iberian Peninsula
-
Portugal (1)
-
Spain
-
Aragon Spain
-
Saragossa Spain (1)
-
Teruel Spain (1)
-
-
Castilla-La Mancha Spain
-
Ciudad Real Spain (2)
-
-
Iberian Mountains (2)
-
Montes de Toledo (1)
-
Sierra Morena (1)
-
-
-
Italy
-
Abruzzi Italy (1)
-
Apennines (1)
-
Friuli-Venezia Giulia Italy (1)
-
Ivrea-Verbano Zone (1)
-
Latium Italy (1)
-
Lombardy Italy (2)
-
Marches Italy
-
Ancona Italy (1)
-
-
Piemonte Italy (1)
-
Trentino-Alto Adige Italy
-
Bolzano Italy (1)
-
-
Umbria Italy (1)
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Veneto Italy (1)
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-
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Variscides (1)
-
Western Europe
-
United Kingdom
-
Great Britain
-
England
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Cornwall England (1)
-
Derbyshire England (3)
-
Devon England (5)
-
Dudley England (1)
-
Lancashire England
-
Clitheroe England (2)
-
-
Shropshire England
-
Wenlock Edge (1)
-
-
Yorkshire England (1)
-
-
Scotland
-
Ayrshire Scotland
-
Girvan Scotland (4)
-
-
-
Wales
-
Powys Wales (1)
-
-
-
-
-
-
Mediterranean region (1)
-
Mediterranean Sea
-
East Mediterranean
-
Adriatic Sea (1)
-
-
-
Mexico
-
Baja California Mexico (1)
-
-
North America
-
Appalachian Basin (1)
-
Great Plains
-
Southern Great Plains (1)
-
-
-
Sacramento Mountains (1)
-
South America
-
Amazon Basin (1)
-
Argentina
-
Jujuy Argentina (1)
-
-
Bolivia
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Cochabamba Bolivia (1)
-
La Paz Bolivia (1)
-
-
Brazil
-
Para Brazil (1)
-
Parnaiba Basin (1)
-
Tocantins Brazil (1)
-
-
Venezuela (1)
-
-
United States
-
Alabama
-
Madison County Alabama (1)
-
-
Alaska (1)
-
California
-
Inyo County California
-
Inyo Mountains (1)
-
-
-
Illinois (1)
-
Indiana
-
Montgomery County Indiana (1)
-
-
Iowa
-
Des Moines County Iowa (1)
-
Marshall County Iowa (1)
-
-
Kansas (1)
-
Kentucky
-
Bath County Kentucky (2)
-
Carter County Kentucky (1)
-
Clinton County Kentucky (1)
-
Cumberland County Kentucky (1)
-
Hardin County Kentucky (2)
-
Mason County Kentucky (1)
-
Menifee County Kentucky (1)
-
Rowan County Kentucky (1)
-
Russell County Kentucky (1)
-
Wayne County Kentucky (1)
-
-
Michigan (1)
-
Midcontinent (3)
-
Minnesota (1)
-
Missouri (1)
-
Montana (1)
-
Nevada
-
Clark County Nevada (1)
-
-
New Mexico
-
Otero County New Mexico (1)
-
Sierra County New Mexico (1)
-
-
New York
-
Oneida County New York (1)
-
-
Ohio
-
Ashland County Ohio (1)
-
Darke County Ohio (1)
-
Greene County Ohio (1)
-
Medina County Ohio (1)
-
Miami County Ohio (1)
-
Summit County Ohio (1)
-
Wayne County Ohio (1)
-
-
Oklahoma
-
Pontotoc County Oklahoma (2)
-
-
Tennessee
-
Lawrence County Tennessee (1)
-
-
Utah
-
Millard County Utah (2)
-
Utah County Utah (1)
-
-
West Virginia
-
Grant County West Virginia (1)
-
Preston County West Virginia (1)
-
-
-
-
commodities
-
construction materials
-
dimension stone (1)
-
-
mineral exploration (1)
-
petroleum (1)
-
-
elements, isotopes
-
carbon
-
C-13/C-12 (2)
-
-
isotope ratios (2)
-
isotopes
-
stable isotopes
-
C-13/C-12 (2)
-
O-18/O-16 (1)
-
-
-
oxygen
-
O-18/O-16 (1)
-
-
-
fossils
-
Chordata
-
Vertebrata (1)
-
-
ichnofossils (2)
-
Invertebrata
-
Arthropoda
-
Mandibulata
-
Insecta
-
Pterygota
-
Neoptera
-
Endopterygota
-
Hymenoptera (1)
-
-
-
-
-
-
-
Brachiopoda
-
Articulata
-
Orthida (1)
-
-
-
Cnidaria
-
Anthozoa
-
Zoantharia
-
Rugosa (2)
-
-
-
-
Echinodermata
-
Asterozoa
-
Stelleroidea
-
Ophiuroidea (1)
-
-
-
Crinozoa
-
Blastoidea (3)
-
Crinoidea
-
Inadunata (1)
-
-
-
Echinozoa
-
Cyclocystoidea (2)
-
Echinoidea (4)
-
Edrioasteroidea (1)
-
-
-
Mollusca
-
Cephalopoda
-
Ammonoidea
-
Ammonites (1)
-
-
-
-
Porifera
-
Hexactinellida (1)
-
-
Protista
-
Foraminifera
-
Fusulinina
-
Fusulinidae (1)
-
-
Rotaliina
-
Lagenidae (1)
-
Nodosariacea
-
Nodosariidae
-
Lenticulina (1)
-
Nodosaria (1)
-
-
-
-
-
-
-
microfossils
-
Conodonta (2)
-
Fusulinina
-
Fusulinidae (1)
-
-
-
problematic fossils (1)
-
-
geologic age
-
Cenozoic
-
Quaternary
-
Pleistocene (1)
-
-
Tertiary
-
Neogene
-
Pliocene (1)
-
-
-
-
Mesozoic
-
Cretaceous
-
Upper Cretaceous
-
Campanian (2)
-
Rosario Formation (1)
-
Santonian (1)
-
Senonian (2)
-
-
-
Jurassic (1)
-
Triassic
-
Lower Triassic
-
Permian-Triassic boundary (2)
-
-
Middle Triassic
-
Ladinian (1)
-
-
Upper Triassic (1)
-
-
-
Paleozoic
-
Bird Spring Formation (1)
-
Carboniferous
-
Lower Carboniferous
-
Dinantian (4)
-
-
Mississippian
-
Borden Group (2)
-
Lower Mississippian
-
Cuyahoga Formation (2)
-
Fort Payne Formation (2)
-
Kinderhookian (2)
-
Lake Valley Formation (2)
-
Osagian
-
Burlington Limestone (3)
-
-
Tournaisian (4)
-
-
Middle Mississippian
-
Visean (6)
-
-
Upper Mississippian
-
Chesterian (2)
-
Greenbrier Limestone (1)
-
Serpukhovian (2)
-
-
-
Pennsylvanian (2)
-
-
Devonian
-
Lower Devonian
-
Emsian (3)
-
-
Middle Devonian
-
Eifelian (1)
-
Givetian (1)
-
-
Upper Devonian
-
Famennian (4)
-
Frasnian (1)
-
-
-
Ellis Bay Formation (1)
-
lower Paleozoic (2)
-
Ordovician
-
Acoite Formation (1)
-
Lower Ordovician
-
Arenigian (1)
-
Fillmore Formation (2)
-
Floian (3)
-
Ibexian (1)
-
Tremadocian (4)
-
-
Middle Ordovician
-
Darriwilian (2)
-
Llandeilian (1)
-
Llanvirnian (1)
-
Table Head Group (1)
-
Whiterockian (1)
-
-
Trenton Group (1)
-
Upper Ordovician
-
Ashgillian (2)
-
Cincinnatian
-
Maysvillian (1)
-
-
Fairview Formation (1)
-
Katian (6)
-
Maquoketa Formation (1)
-
Red River Formation (1)
-
Sandbian (1)
-
-
Viola Limestone (1)
-
-
Permian
-
Lower Permian
-
Cisuralian
-
Asselian (1)
-
-
-
Upper Permian
-
Lopingian
-
Changhsingian (1)
-
-
Permian-Triassic boundary (2)
-
-
-
Silurian
-
Henryhouse Formation (1)
-
Lower Silurian
-
Brassfield Formation (3)
-
Llandovery
-
Aeronian (3)
-
Rhuddanian (1)
-
Telychian (1)
-
-
Wenlock
-
Homerian (1)
-
-
-
Upper Silurian
-
Ludlow (1)
-
Pridoli (2)
-
-
-
Taiyuan Formation (1)
-
upper Paleozoic (1)
-
-
-
igneous rocks
-
igneous rocks
-
carbonatites (1)
-
kamafugite (1)
-
volcanic rocks (1)
-
-
-
metamorphic rocks
-
metamorphic rocks
-
metasedimentary rocks (1)
-
-
turbidite (1)
-
-
minerals
-
silicates
-
framework silicates
-
leucite (1)
-
sodalite group
-
hauyne (1)
-
-
-
orthosilicates
-
sorosilicates
-
melilite group
-
melilite (1)
-
-
-
-
sheet silicates
-
mica group (1)
-
-
-
-
Primary terms
-
Africa
-
North Africa
-
Atlas Mountains
-
Moroccan Atlas Mountains
-
Anti-Atlas (2)
-
-
-
Morocco
-
Moroccan Atlas Mountains
-
Anti-Atlas (2)
-
-
Tafilalt (2)
-
-
-
-
Arctic region (1)
-
Asia
-
Far East
-
China
-
Guizhou China (3)
-
Henan China (1)
-
Nanpanjiang Basin (1)
-
South China Block (2)
-
Xinjiang China
-
Junggar (1)
-
-
-
Korea
-
South Korea (1)
-
-
Mongolia (1)
-
-
Middle East
-
Iran
-
Elburz (1)
-
-
Turkey
-
Anatolia (1)
-
-
-
Omolon Block (1)
-
Siberia (1)
-
-
Atlantic Ocean
-
North Atlantic
-
Rockall Trough (1)
-
-
-
bibliography (1)
-
biogeography (14)
-
Canada
-
Eastern Canada
-
Newfoundland and Labrador
-
Newfoundland
-
Port au Port Peninsula (1)
-
-
-
Ontario
-
Simcoe County Ontario (1)
-
-
Quebec
-
Anticosti Island (2)
-
-
-
Nunavut
-
Ellesmere Island (1)
-
-
Queen Elizabeth Islands
-
Ellesmere Island (1)
-
-
Western Canada
-
British Columbia
-
Vancouver Island (2)
-
-
Manitoba (1)
-
Northwest Territories (1)
-
-
-
carbon
-
C-13/C-12 (2)
-
-
Cenozoic
-
Quaternary
-
Pleistocene (1)
-
-
Tertiary
-
Neogene
-
Pliocene (1)
-
-
-
-
Chordata
-
Vertebrata (1)
-
-
construction materials
-
dimension stone (1)
-
-
continental shelf (1)
-
crust (2)
-
data processing (1)
-
deformation (1)
-
diagenesis (1)
-
Earth (1)
-
economic geology (1)
-
Europe
-
Alps
-
Eastern Alps
-
Dolomites (1)
-
-
-
Baltic region
-
Estonia
-
Saaremaa (1)
-
-
-
Central Europe
-
Germany
-
Eifel (2)
-
Rhineland-Palatinate Germany (1)
-
-
-
Rhenish Schiefergebirge
-
Eifel (2)
-
-
Southern Europe
-
Iberian Peninsula
-
Portugal (1)
-
Spain
-
Aragon Spain
-
Saragossa Spain (1)
-
Teruel Spain (1)
-
-
Castilla-La Mancha Spain
-
Ciudad Real Spain (2)
-
-
Iberian Mountains (2)
-
Montes de Toledo (1)
-
Sierra Morena (1)
-
-
-
Italy
-
Abruzzi Italy (1)
-
Apennines (1)
-
Friuli-Venezia Giulia Italy (1)
-
Ivrea-Verbano Zone (1)
-
Latium Italy (1)
-
Lombardy Italy (2)
-
Marches Italy
-
Ancona Italy (1)
-
-
Piemonte Italy (1)
-
Trentino-Alto Adige Italy
-
Bolzano Italy (1)
-
-
Umbria Italy (1)
-
Veneto Italy (1)
-
-
-
Variscides (1)
-
Western Europe
-
United Kingdom
-
Great Britain
-
England
-
Cornwall England (1)
-
Derbyshire England (3)
-
Devon England (5)
-
Dudley England (1)
-
Lancashire England
-
Clitheroe England (2)
-
-
Shropshire England
-
Wenlock Edge (1)
-
-
Yorkshire England (1)
-
-
Scotland
-
Ayrshire Scotland
-
Girvan Scotland (4)
-
-
-
Wales
-
Powys Wales (1)
-
-
-
-
-
-
faults (1)
-
geochemistry (1)
-
geophysical methods (1)
-
government agencies
-
survey organizations (1)
-
-
ichnofossils (2)
-
igneous rocks
-
carbonatites (1)
-
kamafugite (1)
-
volcanic rocks (1)
-
-
Invertebrata
-
Arthropoda
-
Mandibulata
-
Insecta
-
Pterygota
-
Neoptera
-
Endopterygota
-
Hymenoptera (1)
-
-
-
-
-
-
-
Brachiopoda
-
Articulata
-
Orthida (1)
-
-
-
Cnidaria
-
Anthozoa
-
Zoantharia
-
Rugosa (2)
-
-
-
-
Echinodermata
-
Asterozoa
-
Stelleroidea
-
Ophiuroidea (1)
-
-
-
Crinozoa
-
Blastoidea (3)
-
Crinoidea
-
Inadunata (1)
-
-
-
Echinozoa
-
Cyclocystoidea (2)
-
Echinoidea (4)
-
Edrioasteroidea (1)
-
-
-
Mollusca
-
Cephalopoda
-
Ammonoidea
-
Ammonites (1)
-
-
-
-
Porifera
-
Hexactinellida (1)
-
-
Protista
-
Foraminifera
-
Fusulinina
-
Fusulinidae (1)
-
-
Rotaliina
-
Lagenidae (1)
-
Nodosariacea
-
Nodosariidae
-
Lenticulina (1)
-
Nodosaria (1)
-
-
-
-
-
-
-
isostasy (1)
-
isotopes
-
stable isotopes
-
C-13/C-12 (2)
-
O-18/O-16 (1)
-
-
-
Mediterranean region (1)
-
Mediterranean Sea
-
East Mediterranean
-
Adriatic Sea (1)
-
-
-
Mesozoic
-
Cretaceous
-
Upper Cretaceous
-
Campanian (2)
-
Rosario Formation (1)
-
Santonian (1)
-
Senonian (2)
-
-
-
Jurassic (1)
-
Triassic
-
Lower Triassic
-
Permian-Triassic boundary (2)
-
-
Middle Triassic
-
Ladinian (1)
-
-
Upper Triassic (1)
-
-
-
metamorphic rocks
-
metasedimentary rocks (1)
-
-
Mexico
-
Baja California Mexico (1)
-
-
mineral exploration (1)
-
museums (2)
-
North America
-
Appalachian Basin (1)
-
Great Plains
-
Southern Great Plains (1)
-
-
-
orogeny (2)
-
oxygen
-
O-18/O-16 (1)
-
-
paleoclimatology (1)
-
paleoecology (22)
-
paleogeography (5)
-
paleontology (7)
-
Paleozoic
-
Bird Spring Formation (1)
-
Carboniferous
-
Lower Carboniferous
-
Dinantian (4)
-
-
Mississippian
-
Borden Group (2)
-
Lower Mississippian
-
Cuyahoga Formation (2)
-
Fort Payne Formation (2)
-
Kinderhookian (2)
-
Lake Valley Formation (2)
-
Osagian
-
Burlington Limestone (3)
-
-
Tournaisian (4)
-
-
Middle Mississippian
-
Visean (6)
-
-
Upper Mississippian
-
Chesterian (2)
-
Greenbrier Limestone (1)
-
Serpukhovian (2)
-
-
-
Pennsylvanian (2)
-
-
Devonian
-
Lower Devonian
-
Emsian (3)
-
-
Middle Devonian
-
Eifelian (1)
-
Givetian (1)
-
-
Upper Devonian
-
Famennian (4)
-
Frasnian (1)
-
-
-
Ellis Bay Formation (1)
-
lower Paleozoic (2)
-
Ordovician
-
Acoite Formation (1)
-
Lower Ordovician
-
Arenigian (1)
-
Fillmore Formation (2)
-
Floian (3)
-
Ibexian (1)
-
Tremadocian (4)
-
-
Middle Ordovician
-
Darriwilian (2)
-
Llandeilian (1)
-
Llanvirnian (1)
-
Table Head Group (1)
-
Whiterockian (1)
-
-
Trenton Group (1)
-
Upper Ordovician
-
Ashgillian (2)
-
Cincinnatian
-
Maysvillian (1)
-
-
Fairview Formation (1)
-
Katian (6)
-
Maquoketa Formation (1)
-
Red River Formation (1)
-
Sandbian (1)
-
-
Viola Limestone (1)
-
-
Permian
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Camerata
A lower Silurian (Llandovery) diplobathrid crinoid (Camerata) from mid-Wales
Phylogeny and morphologic evolution of the Ordovician Camerata (Class Crinoidea, Phylum Echinodermata)
Water vascular system of the Crinoidea Camerata
GC Clinopyroxene compositions = triangles. Oricola-Camerata Nuova (OC): dar...
Evolution and Classification of Paleozoic Crinoids
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. The evolution of fossil crinoids is an especially interesting study, because modification in different directions may be observed in each of several structural features. Also, evolution along one line may be accelerated greatly as compared with others. Investigation of the crinoids has special value in elucidating principles of evolution, and conclusions as to the nature of evolution among these organisms provide a basis for a classification that reflects their phylogenetic relations. This paper summarizes extensive researches on Paleozoic crinoids, giving our conclusions as to (1) the natural main divisions among crinoids, (2) the significant evolutionary trends shown by each main group, and (3) a revised classification of Paleozoic crinoids of the world, based on characters that express the inferred most important evolutionary changes. Analysis of fundamental structures of the different types of Paleozoic crinoids leads to recognition of three chief divisions, which are designated as the subclasses Inadunata, Flexibilia, and Camerata. This grouping accords with conclusions of Wachsmuth and Springer rather than those of Bather. Each subclass contains two orders, which in the inadunates and camerates are defined primarily on the presence of one circlet of plates or two circlets below the first ray plates, or radials. These orders are new: Disparata and Cladoidea in the subclass Inadunata, and Monobathra and Diplobathra in the subclass Camerata. The Flexibilia contains the orders Taxocrinoidea and Sagenocrinoidea, named by Springer. Each subclass of Paleozoic crinoids is represented in Middle Ordovician rocks and each persists into Upper Permian beds. They run closely parallel in geologic distribution and they show several common evolutionary trends. (1) Among the Inadunata, evolution affects chiefly the form of the dorsal cup; the number of plates in the lowermost circlet, which reduce by fusion; structure of the posterior side of the cup, including the number and arrangement of so-called anal plates; characters of the anal sac; the nature of articulation of the arms; and structural organization of the arms. Primitive cups of steep-sided conical form are gradually modified to low discoid shapes, concave at the base. The lowermost plates of the cup are reduced from five to one. The anal plates and sac are identifiable in many inadunates as derivatives of the right posterior ray; and as evolution progresses, the anal plates tend to be expelled from the cup. Nearly smooth articular surfaces of ray plates, indicating weak mobility, become strongly ridged and grooved for attachment of muscles and ligaments, indicating great mobility. The arms tend to branch in equal rami, but advancement leads to abundant unequal bifurcations also, and this is followed ultimately by regressive evolution that trends toward simplicity of arm structure. End products of evolutionary change are a low cup having perfect pentamerous symmetry, anal plates lacking in the cup, anal sac weak or absent, and arms having branchlets (pinnules) but otherwise simple. (2) Evolution of the Flexibilia follows much the same course as in the Inadunata, tending to develop perfect pentamerous symmetry. The differentiation of arms and cup becomes obscure in many of these crinoids. (3) Primitive camerate crinoids are distinguished by prominent median ridges along rays in the cup, depressed interray areas composed of very numerous small plates, the posterior interray wider than the others and bearing a median ridge, the lowermost ray plates (radials) laterally separated all around by interray plates, and several plates in each ray incorporated in the cup. Evolution leads to progressive reduction in the number of plates of the lowermost circlet of the cup, obliteration of the median ray ridges and interray depressions, enlargement and upward displacement of interray plates, and reduction in the number of ray plates of the cup. An intermediate evolutionary stage is marked by lateral contact of the radials with one another except at the posterior side, where an anal plate intervenes; an advanced stage is defined by upward displacement of the anal that brings the radials into lateral contact all around. Ultimately all interray plates, including anals, are expelled from the cup, and the arms are free above the radials. At least four different stocks of camerates follow closely parallel courses of evolution that produce homeomorphic end products having simplified structure and perfect or nearly perfect pentamerous symmetry. Similarities in the evolutionary trends of widely different groups of crinoids provide basis for conclusions as to causes and directions of evolution. This comparative study has value in defining principles of evolution. The classification of Paleozoic crinoids offered in this paper covers all known genera of the world, although some are not definitely allocated. Among Inadunata, 14 families containing 64 genera are included in the order Disparata, and 38 families containing 223 genera are included in the order Cladoidea. One family and genus of inadunates is unassigned to an order. Of the 53 inadunate families recognized, 14 are new. Among Flexibilia, 6 genera are placed in the one family of the order Taxocrinoidea, and 42 genera are grouped in 5 families of the order Sagenocrinoidea. Among Camerata, the order Diplobathra contains 8 families and 34 described genera, and the order Monobathra contains 21 families and 94 described genera; of these 29 families, 2 are new. Unassigned to subclasses are 3 families, each consisting of a single genus. Unclassified genera, including unrecognizable forms, are 51 in number, making a total of 518 genera that are assigned to 91 families or unclassified. One new genus, Plummericrinus, from Pennsylvanian and Permian rocks of the midcontinent region of the United States, is described; it is a dicyclic inadunate crinoid.
Character-level rarefaction curves of the three subsets of the AEToL charac...
Character-level rarefaction curves for the internal properties of the three...
New Stratigraphic scheme of the Calcare Rosso along the middle Brembana Val...
Late Ordovician crinoids from the Anti-Atlas region of Morocco
Abstract The crinoid fauna of the Late Ordovician (Sandbian and Katian) of Morocco is sparse, but diverse. The one previously described species, Rosfacrinus robustus Le Menn & Spjeldnaes, 1996 , is now known to be part of an assemblage of at least 10 species, including the new taxa Iocrinus ouzammoui sp. nov. (Disparida), Superlininicrinus advorsa gen. et sp. nov., Isthloucrinus praecursor gen. et a sp. nov. (Cladida) and Euptychocrinus ? atelis sp. nov. (Camerata). The fauna also includes an additional species of Iocrinus , and several camerates including Trichinocrinus sp. and a monobathrid with probable affinities to the Tanaocrinidae. Undeterminable specimens of demonstrably different taxa are described as far as possible. The fauna includes genera previously known from Laurentia and Avalonia, implying unexpected latitudinal dispersal, together with evidence for substantial endemic diversification among cladids and camerates. Several of the taxa have unusual plate arrangements, including a mosaic of primitive and derived characters; this implies that early crinoid diversification was not limited to tropical carbonate facies. The fauna remains poorly known, with low numbers of specimens, and future collecting is likely to increase the diversity significantly.
Carboniferous crinoids
Abstract During the Carboniferous, crinoids were commonly so abundant that their skeletal ossicles formed limestones termed encrinites. Major evolutionary changes occurred within the Camerata and Articuliformes, as the former were displaced by the latter as the dominant clade. Both the Mississippian and the Pennsylvanian subperiods started with high evolutionary rates and ended with low evolutionary rates associated with glaciation. Although not typically used for biostratigraphy, crown-based crinoid genera can be used as biostratigraphic indicators for Carboniferous stages. Paleozoic crinoid biodiversity reached its maximum during the Carboniferous, from which there are numerous well-documented localities with high biodiversity. Faunas from the palaeobiogeographical regions of Laurussia, Palaeo-Tethys and Gondwana are reviewed. For Mississippian crinoids, 37 genera are designated as biostratigraphically useful; and, for the Pennsylvanian, 44 genera are identified. Recognition of the utility of these genera for biostratigraphy is important for dating crinoid deposits, which may be devoid of other biostratigraphically useful fossils, and add to our overall ability to delineate the temporal resolution of life on Earth.