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Cyclospira
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Atrypida
Superfamily:
Protozygoidea
Family:
Cyclospiridae
Formal Genus Name and Reference:
Cyclospira Hall in Hall & CLARKE, 1893, p. 146
Type Species:
Orthis bisulcata EMMONS, 1842, p. 396, OD
Images
(Click to enlarge in a new window)
Fig. 1000, 1a-b. *C$. bisulcata (Emmons), upper Caradoc, New York, USA, $a-d$, dorsal, ventral, lateral, anterior views, x3$, $e-f$, serial sections, x5$, $g-h$, dorsal and lateral reconstruction of brachidia, x5$ (Copper, 1986b).
Synonyms
Triplecella, Aulidospira, ?Cyclorhynchia
Geographic Distribution
North America, Eurasia
Age Range
Beginning Stage in Treatise Usage:
Ordovician (Caradoc)
Beginning International Stage:
Sandbian
Fraction Up In Beginning Stage:
0
Beginning Date:
458.18
Ending Stage in Treatise Usage:
Ordovician (Ashgill)
Ending International Stage:
Hirnantian
Fraction Up In Ending Stage:
100
Ending Date:
443.07
Description
Small, ventribiconvex-planoconvex, subtriangulate to elongate, strongly convex ventral valve, weakly convex to planar dorsal valve, small area anacline-hypercline, apical-transapical foramen, sulcate-bisulcate commissure, shell thickly walled, teeth solid or with small, slitlike dental cavities or nuclei, medially directed spiralia with normally fewer than 4 whorls, jugum or jugal processes absent. [Distinguished from homeomorphic protozyginids by absence of jugum, distinguished from Rozmanospira by presence of more than 1 spiral whorl.]
References
Museum or Author Information
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Atrypida
Superfamily:
Protozygoidea
Family:
Cyclospiridae
Formal Genus Name and Reference:
Cyclospira Hall in Hall & CLARKE, 1893, p. 146
Type Species:
Orthis bisulcata EMMONS, 1842, p. 396, OD
Images
(Click to enlarge in a new window)
Fig. 1000, 1a-b. *C$. bisulcata (Emmons), upper Caradoc, New York, USA, $a-d$, dorsal, ventral, lateral, anterior views, x3$, $e-f$, serial sections, x5$, $g-h$, dorsal and lateral reconstruction of brachidia, x5$ (Copper, 1986b).
Synonyms
Triplecella, Aulidospira, ?Cyclorhynchia
Geographic Distribution
North America, Eurasia
Age Range
Beginning Stage in Treatise Usage:
Ordovician (Caradoc)
Beginning International Stage:
Sandbian
Fraction Up In Beginning Stage:
0
Beginning Date:
458.18
Ending Stage in Treatise Usage:
Ordovician (Ashgill)
Ending International Stage:
Hirnantian
Fraction Up In Ending Stage:
100
Ending Date:
443.07
Description
Small, ventribiconvex-planoconvex, subtriangulate to elongate, strongly convex ventral valve, weakly convex to planar dorsal valve, small area anacline-hypercline, apical-transapical foramen, sulcate-bisulcate commissure, shell thickly walled, teeth solid or with small, slitlike dental cavities or nuclei, medially directed spiralia with normally fewer than 4 whorls, jugum or jugal processes absent. [Distinguished from homeomorphic protozyginids by absence of jugum, distinguished from Rozmanospira by presence of more than 1 spiral whorl.]