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Bifida
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Athyridida
Superfamily:
Anoplothecoidea
Family:
Anaplothecidae
Formal Genus Name and Reference:
Bifida Davidson, 1882, p. 27
Type Species:
Terebratula lepida d'Archiac & de VERNEULE, 1842, p. 368, OD
Images
(Click to enlarge in a new window)
Fig. 1096, $1 a-p$. $* B$. lepida (d'Archiac & de Verneuil)
Synonyms
Dahlispira
Geographic Distribution
Eurasia, North America
Age Range
Beginning Stage in Treatise Usage:
Lower Devonian (Emsian)
Beginning International Stage:
Emsian
Fraction Up In Beginning Stage:
0
Beginning Date:
410.51
Ending Stage in Treatise Usage:
Middle Devonian (lower Givetian)
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
35
Ending Date:
383.06
Description
Small ventribiconvex shells, commonly with carinate ventral midrib pair, concentric growth lamellae, distinct, rhythmic, commonly developed as bushy, spinose external layer covering shell, commissure rectimarginate or weakly sulcate, short, small, solid teeth with inner notch for dorsal socket plates, strong ventral median septum, thick cardinal plate with weak cardinal process, crura medial, with high angles at junction with spiralia, spiralia grooved, with 3 to 7 whorls, jugal saddle resting on high dorsal septum, slightly projected as abortive accessory lamellae. Similarly grooved spiralia as in Navispira and Coelospira, but differing externally in small shell, very enlarged ventral midrib pair, differs from Anoplotheca mainly in smaller size, distinct concentric growth lamellae, and bushy spinose fibers.
References
Museum or Author Information
Classification
Phylum:
Brachiopoda
Class:
Rhynchonellata
Order:
Athyridida
Superfamily:
Anoplothecoidea
Family:
Anaplothecidae
Formal Genus Name and Reference:
Bifida Davidson, 1882, p. 27
Type Species:
Terebratula lepida d'Archiac & de VERNEULE, 1842, p. 368, OD
Images
(Click to enlarge in a new window)
Fig. 1096, $1 a-p$. $* B$. lepida (d'Archiac & de Verneuil)
Synonyms
Dahlispira
Geographic Distribution
Eurasia, North America
Age Range
Beginning Stage in Treatise Usage:
Lower Devonian (Emsian)
Beginning International Stage:
Emsian
Fraction Up In Beginning Stage:
0
Beginning Date:
410.51
Ending Stage in Treatise Usage:
Middle Devonian (lower Givetian)
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
35
Ending Date:
383.06
Description
Small ventribiconvex shells, commonly with carinate ventral midrib pair, concentric growth lamellae, distinct, rhythmic, commonly developed as bushy, spinose external layer covering shell, commissure rectimarginate or weakly sulcate, short, small, solid teeth with inner notch for dorsal socket plates, strong ventral median septum, thick cardinal plate with weak cardinal process, crura medial, with high angles at junction with spiralia, spiralia grooved, with 3 to 7 whorls, jugal saddle resting on high dorsal septum, slightly projected as abortive accessory lamellae. Similarly grooved spiralia as in Navispira and Coelospira, but differing externally in small shell, very enlarged ventral midrib pair, differs from Anoplotheca mainly in smaller size, distinct concentric growth lamellae, and bushy spinose fibers.