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Isorthis
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Orthida
Superfamily:
Dalmanelloidea
Family:
Dalmanellidae
Formal Genus Name and Reference:
Isorthis KOZŁOWSKI, 1929, p. 29
Type Species:
Dalmanella (Isorthis) szajnochai, OD
Images
(Click to enlarge in a new window)
Fig. 571, 2a–h. *I. (A.) arcuaria (HALL & CLARKE), Ludlow, Tennessee; a–e, ventral, dorsal, posterior, lateral, anterior views of conjoined valves, ×1; f, ventral interior, ×3; g, dorsal interior, ×1; h, anterior detail of dorsal interior, × 5 (Walmsley & Boucot, 1975).
Synonyms
Geographic Distribution
cosmopolitan
Age Range
Beginning Stage in Treatise Usage:
Lower Silurian (Llandovery)
Beginning International Stage:
Rhuddanian
Fraction Up In Beginning Stage:
0
Beginning Date:
443.07
Ending Stage in Treatise Usage:
Middle Devonian (Givetian)
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
100
Ending Date:
378.9
Description
Subcircular, subequally biconvex, rectimarginate to weakly unisulcate valves, ventral interior with dental fossettes, dorsal interior with variably lobate cardinal process and brachiophore plates divergent ventrally
References
Museum or Author Information
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Orthida
Superfamily:
Dalmanelloidea
Family:
Dalmanellidae
Formal Genus Name and Reference:
Isorthis KOZŁOWSKI, 1929, p. 29
Type Species:
Dalmanella (Isorthis) szajnochai, OD
Images
(Click to enlarge in a new window)
Fig. 571, 2a–h. *I. (A.) arcuaria (HALL & CLARKE), Ludlow, Tennessee; a–e, ventral, dorsal, posterior, lateral, anterior views of conjoined valves, ×1; f, ventral interior, ×3; g, dorsal interior, ×1; h, anterior detail of dorsal interior, × 5 (Walmsley & Boucot, 1975).
Synonyms
Geographic Distribution
cosmopolitan
Age Range
Beginning Stage in Treatise Usage:
Lower Silurian (Llandovery)
Beginning International Stage:
Rhuddanian
Fraction Up In Beginning Stage:
0
Beginning Date:
443.07
Ending Stage in Treatise Usage:
Middle Devonian (Givetian)
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
100
Ending Date:
378.9
Description
Subcircular, subequally biconvex, rectimarginate to weakly unisulcate valves, ventral interior with dental fossettes, dorsal interior with variably lobate cardinal process and brachiophore plates divergent ventrally