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Erismodus
Classification
Phylum:
Conodonta
Class:
Conodonta
Order:
Conodontophorida
Superfamily:
Chirognathacea
Family:
Multioistodontidae
Formal Genus Name and Reference:
Erismodus Branson & MEHL, 1933a, p. 25
Type Species:
E. typus, OD
Images
(Click to enlarge in a new window)
Fig. 86,2. E. radicans (HINDE), Chazy., Can.(Que.); Pa element, ant. view, X20 (Hass, 1962).
Synonyms
Microcoelodus; Ptiloconus; Multicornis
Geographic Distribution
N.Am.-Eu.-Asia(Sib.)
Age Range
Beginning Stage in Treatise Usage:
M.Dev.
Beginning International Stage:
Eifelian
Fraction Up In Beginning Stage:
0
Beginning Date:
394.3
Ending Stage in Treatise Usage:
M.Dev.
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
100
Ending Date:
378.9
Description
Apparatus of type species unknown but septimembrate in closely similar forms, All elements fibrous, most relatively robust, with peglike, discrete denticles, shallow basal cavity, and distinct cusp. Pa dements angulate, laterally bowed, with relatively long posterior and anterior processes forming wide angle with each other. Pb elements similar to Pa elements but with larger process angle and with abruptly arched posterior process behind cusp. M elements modified bipennate with denticulate anterior cusp margin deflected laterally and upper edge of base provided with one or a few denticles near distal end. S elements forming transition series from alate through digyrate to bipennate, all modified. Sa elements of two types, one symmetrical, one slightly asymmetrical with process angle from 90°to 180°, no posterior process, and anterobasal portion of cusp produced into tonguelike structure in some species. Sb elements markedly asymmetrical with process angle of about 90°. Sc elements also markedly asymmetrical with short, laterally denticulate anterior process and short, denticulate posterior process. [Apparatus reconstruction: CARNES, 1975.]
References
Branson, E. B., & Branson, C. C., , & Mehl, M. G., 1933a, Conodont studies no. 1: Conodonts from the Harding sandstone of Colorado; Bainbridge (Silurian) of Missouri; Jefferson City (Lower Ordovician) of Missouri: Univ. Mo. Stud., v. 8, no. 1, p. 5-72, pl. 1-4.
Museum or Author Information
Classification
Phylum:
Conodonta
Class:
Conodonta
Order:
Conodontophorida
Superfamily:
Chirognathacea
Family:
Multioistodontidae
Formal Genus Name and Reference:
Erismodus Branson & MEHL, 1933a, p. 25
Type Species:
E. typus, OD
Images
(Click to enlarge in a new window)
Fig. 86,2. E. radicans (HINDE), Chazy., Can.(Que.); Pa element, ant. view, X20 (Hass, 1962).
Synonyms
Microcoelodus; Ptiloconus; Multicornis
Geographic Distribution
N.Am.-Eu.-Asia(Sib.)
Age Range
Beginning Stage in Treatise Usage:
M.Dev.
Beginning International Stage:
Eifelian
Fraction Up In Beginning Stage:
0
Beginning Date:
394.3
Ending Stage in Treatise Usage:
M.Dev.
Ending International Stage:
Givetian
Fraction Up In Ending Stage:
100
Ending Date:
378.9
Description
Apparatus of type species unknown but septimembrate in closely similar forms, All elements fibrous, most relatively robust, with peglike, discrete denticles, shallow basal cavity, and distinct cusp. Pa dements angulate, laterally bowed, with relatively long posterior and anterior processes forming wide angle with each other. Pb elements similar to Pa elements but with larger process angle and with abruptly arched posterior process behind cusp. M elements modified bipennate with denticulate anterior cusp margin deflected laterally and upper edge of base provided with one or a few denticles near distal end. S elements forming transition series from alate through digyrate to bipennate, all modified. Sa elements of two types, one symmetrical, one slightly asymmetrical with process angle from 90°to 180°, no posterior process, and anterobasal portion of cusp produced into tonguelike structure in some species. Sb elements markedly asymmetrical with process angle of about 90°. Sc elements also markedly asymmetrical with short, laterally denticulate anterior process and short, denticulate posterior process. [Apparatus reconstruction: CARNES, 1975.]
References
Branson, E. B., & Branson, C. C., , & Mehl, M. G., 1933a, Conodont studies no. 1: Conodonts from the Harding sandstone of Colorado; Bainbridge (Silurian) of Missouri; Jefferson City (Lower Ordovician) of Missouri: Univ. Mo. Stud., v. 8, no. 1, p. 5-72, pl. 1-4.