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Mica
Classification
Phylum:
Brachiopoda
Subphylum:
Rhynchonelliformea
Class:
Rhynchonellata
Order:
Athyridida
Suborder:
Athyrididina
Superfamily:
Athyridoidea
Family:
Athyrididae
Subfamily:
Didymothyridinae
Formal Genus Name and Reference:
Mica Baranov & AL'KHOVIK, 2001, p. 44
Type Species:
M. borea, M
Images
(Click to enlarge in a new window)
Fig. 1837, 1a-l. * M. borea, a-d, holotype, dorsal, ventral, lateral, and anterior views, Krivoi Ruchei Formation, Ulakhan-Sis Ridge, eastern Yakutia, IGN SO RAN 171/16, x3 (Baranov & Al'khovik, 2001), e-l, transverse serial sections 1.3, 1.5, 1.8, 2.2, 2.4, 2.7, 3.0, 3.3\n\nSource 1:\neastern Yakutia, IGN SO RAN 171 / 1, x3, e-f, partly exfoliated ventral valve showing tubular ribs, basal Datna Formation, Tas-Khayakhtakh Ridge, IGN SO RAN 171/7, x3, x10 (Baranov & Al'khovik, 2001), g-s, transverse serial sections 0.5, 0.7, 0.8, 1.1, 1.85, 2.6, 2.7, 3.4, 3.6, 3.9, 4.1, 4.5, 4.6 ~mm from ventral umbo, distance from ventral umbo to first section approximate, lower Sette-Daban Formation, Sette-Daban Ridge, southern Verkhoyansk region, eastern Yakutia IGN SO RAN 171/8, t, transverse serial section at approximately 2.0 mm from ventral umbo, lower Sette-Daban Formation, Sette-Daban Ridge, southern Verkhoyansk region, eastern Yakutia, IGN SO RAN 171/9 (adapted from Baranov & Al'khovik, 2001).
Synonyms
Micathyris
Geographic Distribution
Ulakhan-Sis Ridge, eastern Yakutia
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:
Lower Devonian (Emsian)
Ending International Stage:
Emsian
Fraction Up In Ending Stage:
100
Ending Date:
394.3
Description
Very small, subequally biconvex shells with outline elongate subelliptical, dorsal fold and ventral sulcus absent or poorly developed anteriorly, growth lines weak, ventral beak high, slightly curved, delthyrium reportedly covered by deltidial plates, dental plates thin, high, short, subparallel, teeth small, hinge plate ventrally concave, apically perforated, septum or dorsal myophragm absent, spiralia with up to four laterally directed whorls, jugum poorly preserved, seemingly without saddle, stem, or accessory jugal lamellae. [Mica resembles Fastigata, Glassina, Dogdathyiris, or Svetlania in outline and lateral profile, but differs internally by nature of cardinalia and brachidium; this genus requires revision.]
References
Museum or Author Information
Classification
Phylum:
Brachiopoda
Subphylum:
Rhynchonelliformea
Class:
Rhynchonellata
Order:
Athyridida
Suborder:
Athyrididina
Superfamily:
Athyridoidea
Family:
Athyrididae
Subfamily:
Didymothyridinae
Formal Genus Name and Reference:
Mica Baranov & AL'KHOVIK, 2001, p. 44
Type Species:
M. borea, M
Images
(Click to enlarge in a new window)
Fig. 1837, 1a-l. * M. borea, a-d, holotype, dorsal, ventral, lateral, and anterior views, Krivoi Ruchei Formation, Ulakhan-Sis Ridge, eastern Yakutia, IGN SO RAN 171/16, x3 (Baranov & Al'khovik, 2001), e-l, transverse serial sections 1.3, 1.5, 1.8, 2.2, 2.4, 2.7, 3.0, 3.3\n\nSource 1:\neastern Yakutia, IGN SO RAN 171 / 1, x3, e-f, partly exfoliated ventral valve showing tubular ribs, basal Datna Formation, Tas-Khayakhtakh Ridge, IGN SO RAN 171/7, x3, x10 (Baranov & Al'khovik, 2001), g-s, transverse serial sections 0.5, 0.7, 0.8, 1.1, 1.85, 2.6, 2.7, 3.4, 3.6, 3.9, 4.1, 4.5, 4.6 ~mm from ventral umbo, distance from ventral umbo to first section approximate, lower Sette-Daban Formation, Sette-Daban Ridge, southern Verkhoyansk region, eastern Yakutia IGN SO RAN 171/8, t, transverse serial section at approximately 2.0 mm from ventral umbo, lower Sette-Daban Formation, Sette-Daban Ridge, southern Verkhoyansk region, eastern Yakutia, IGN SO RAN 171/9 (adapted from Baranov & Al'khovik, 2001).
Synonyms
Micathyris
Geographic Distribution
Ulakhan-Sis Ridge, eastern Yakutia
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:
Lower Devonian (Emsian)
Ending International Stage:
Emsian
Fraction Up In Ending Stage:
100
Ending Date:
394.3
Description
Very small, subequally biconvex shells with outline elongate subelliptical, dorsal fold and ventral sulcus absent or poorly developed anteriorly, growth lines weak, ventral beak high, slightly curved, delthyrium reportedly covered by deltidial plates, dental plates thin, high, short, subparallel, teeth small, hinge plate ventrally concave, apically perforated, septum or dorsal myophragm absent, spiralia with up to four laterally directed whorls, jugum poorly preserved, seemingly without saddle, stem, or accessory jugal lamellae. [Mica resembles Fastigata, Glassina, Dogdathyiris, or Svetlania in outline and lateral profile, but differs internally by nature of cardinalia and brachidium; this genus requires revision.]