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Quadraticephalus
Classification
Phylum:
Unknown
Class:
Trilobata
Order:
Ptychopariida
Superfamily:
Ptychaspidacea
Family:
Ptychaspididae
Formal Genus Name and Reference:
Quadraticephalus SUN, 1924
Type Species:
Q. walcotti
Images
(Click to enlarge in a new window)
Fig. 237, 8a. *Q. walcotti, China(Shantung), cran. (with librigena) x1 (288), Fig. 237, 8b, c. Q. teres Resser & Endo, in Endo & Resser (1937), Manch., 8 b, c, cran., pyg., x4 (37)
Synonyms
Geographic Distribution
E.Asia
Age Range
Beginning Stage in Treatise Usage:
Upper Cambrian(Fengshanian)
Beginning International Stage:
Jiangshanian
Fraction Up In Beginning Stage:
87.5
Beginning Date:
491.4
Ending Stage in Treatise Usage:
Upper Cambrian(Fengshanian)
Ending International Stage:
Cambrian Stage 10
Fraction Up In Ending Stage:
100
Ending Date:
486.85
Description
Glabella parallel-sided, subrectangular, front nearly straight, anterior border furrow shallow or obsolete, preglabellar field downsloping, eyes of medium size, slightly in front of mid-length of glabella, fixigenae upsloping, with palpebral areas more than 0.3 of glabellar width, posterior areas large, subtriangular, long (tr.). Pygidium broadly transverse, furrows shallow, no border furrow, 4 axial rings, 3 broad pleurae, interpleural grooves extending to margin. Surface ridged or punctate.
References
Museum or Author Information
Classification
Phylum:
Unknown
Class:
Trilobata
Order:
Ptychopariida
Superfamily:
Ptychaspidacea
Family:
Ptychaspididae
Formal Genus Name and Reference:
Quadraticephalus SUN, 1924
Type Species:
Q. walcotti
Images
(Click to enlarge in a new window)
Fig. 237, 8a. *Q. walcotti, China(Shantung), cran. (with librigena) x1 (288), Fig. 237, 8b, c. Q. teres Resser & Endo, in Endo & Resser (1937), Manch., 8 b, c, cran., pyg., x4 (37)
Synonyms
Geographic Distribution
E.Asia
Age Range
Beginning Stage in Treatise Usage:
Upper Cambrian(Fengshanian)
Beginning International Stage:
Jiangshanian
Fraction Up In Beginning Stage:
87.5
Beginning Date:
491.4
Ending Stage in Treatise Usage:
Upper Cambrian(Fengshanian)
Ending International Stage:
Cambrian Stage 10
Fraction Up In Ending Stage:
100
Ending Date:
486.85
Description
Glabella parallel-sided, subrectangular, front nearly straight, anterior border furrow shallow or obsolete, preglabellar field downsloping, eyes of medium size, slightly in front of mid-length of glabella, fixigenae upsloping, with palpebral areas more than 0.3 of glabellar width, posterior areas large, subtriangular, long (tr.). Pygidium broadly transverse, furrows shallow, no border furrow, 4 axial rings, 3 broad pleurae, interpleural grooves extending to margin. Surface ridged or punctate.