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Janiceps
Classification
Phylum:
Brachiopoda
Subphylum:
Rhynchonelliformea
Class:
Rhynchonellata
Order:
Athyridida
Suborder:
Athyrididina
Superfamily:
Athyridoidea
Family:
Athyrididae
Subfamily:
Janicepsinae
Formal Genus Name and Reference:
Janiceps Frech, 1901, p. 551, emend., POSENATO, 2001, p. 205
Type Species:
Spirigera peracuta STache, 1878, p. 152, SD Schuchert & LEVENE, 1929, p. 70
Images
(Click to enlarge in a new window)
Fig. 1841 a-g . * J. peracuta (Stache), upper Changhsingian, southern Alps, a-e, dorsal, ventral, lateral, anterior, and posterior views, Monte Croce di Comelico, Stache collection, MGBW 1878/1/47a, × 1.5 (Posenato, 2001, photographs courtesy of R. Posenato), f-g, reconstruction of nternal characters of dorsal valve viewed ventrally and laterally, Val Brutta, MDTF 6 (Posenato, 2001). [See also Fig . 1045, 3 a–t in a lvare Z & rOng, 2002; and revision in Posenato, 2001.]
Synonyms
Geographic Distribution
Italy (southern Alps), Transcaucasia (upper Djulfian to lower Dorashamian), China (Wuchiapingian and Changhsingian)
Age Range
Beginning Stage in Treatise Usage:
Upper Permian (Changhsingian)
Beginning International Stage:
Changhsingian
Fraction Up In Beginning Stage:
0
Beginning Date:
254.24
Ending Stage in Treatise Usage:
Upper Permian (Changhsingian)
Ending International Stage:
Changhsingian
Fraction Up In Ending Stage:
100
Ending Date:
251.9
Description
Small to medium sized, subtrigonal, biconvex, and astrophic shells with ventral sulcus and dorsal sulcate fold, lateral grooves may be developed, anterolateral extremities pointed or rounded, ventral umbo small, recurved, and pointed, only very fine growth lines, pedicle support absent, dental plates thin and short, mostly buried in secondary shell material, cardinal plate subquadrangular and thick, inner socket ridges high, dorsal foramen absent, cardinal flanges variably developed, dorsal myophragm or septum absent, jugum as in Athyris with short accessory jugal lamellae.
References
Museum or Author Information
Classification
Phylum:
Brachiopoda
Subphylum:
Rhynchonelliformea
Class:
Rhynchonellata
Order:
Athyridida
Suborder:
Athyrididina
Superfamily:
Athyridoidea
Family:
Athyrididae
Subfamily:
Janicepsinae
Formal Genus Name and Reference:
Janiceps Frech, 1901, p. 551, emend., POSENATO, 2001, p. 205
Type Species:
Spirigera peracuta STache, 1878, p. 152, SD Schuchert & LEVENE, 1929, p. 70
Images
(Click to enlarge in a new window)
Fig. 1841 a-g . * J. peracuta (Stache), upper Changhsingian, southern Alps, a-e, dorsal, ventral, lateral, anterior, and posterior views, Monte Croce di Comelico, Stache collection, MGBW 1878/1/47a, × 1.5 (Posenato, 2001, photographs courtesy of R. Posenato), f-g, reconstruction of nternal characters of dorsal valve viewed ventrally and laterally, Val Brutta, MDTF 6 (Posenato, 2001). [See also Fig . 1045, 3 a–t in a lvare Z & rOng, 2002; and revision in Posenato, 2001.]
Synonyms
Geographic Distribution
Italy (southern Alps), Transcaucasia (upper Djulfian to lower Dorashamian), China (Wuchiapingian and Changhsingian)
Age Range
Beginning Stage in Treatise Usage:
Upper Permian (Changhsingian)
Beginning International Stage:
Changhsingian
Fraction Up In Beginning Stage:
0
Beginning Date:
254.24
Ending Stage in Treatise Usage:
Upper Permian (Changhsingian)
Ending International Stage:
Changhsingian
Fraction Up In Ending Stage:
100
Ending Date:
251.9
Description
Small to medium sized, subtrigonal, biconvex, and astrophic shells with ventral sulcus and dorsal sulcate fold, lateral grooves may be developed, anterolateral extremities pointed or rounded, ventral umbo small, recurved, and pointed, only very fine growth lines, pedicle support absent, dental plates thin and short, mostly buried in secondary shell material, cardinal plate subquadrangular and thick, inner socket ridges high, dorsal foramen absent, cardinal flanges variably developed, dorsal myophragm or septum absent, jugum as in Athyris with short accessory jugal lamellae.