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Periodon
Classification
Phylum:
Conodonta
Class:
Conodonta
Order:
Conodontophorida
Superfamily:
Prioniodontacea
Family:
Periodontidae
Formal Genus Name and Reference:
Periodon HADDING, 1913, p. 33
Type Species:
P. aculeatus, M
Images
(Click to enlarge in a new window)
Fig. 76, 1. P. grandis (Ethington), M.Ord. (Prosser F.), USA (Minn.), 1a, c, two types of P elements, lat. views, X61, 1 b, M element, lat. view, X61, 1 d-f, three types of S clements, lat. views, X77, X 102, X 110 (Bergström, n)
Synonyms
Loxognathus; Falodus
Geographic Distribution
Ord., Eu.-N.Am.-S.Am.-Aus-tralia (N.Z.)
Age Range
Beginning Stage in Treatise Usage:
Ord.
Beginning International Stage:
Tremadocian
Fraction Up In Beginning Stage:
0
Beginning Date:
486.85
Ending Stage in Treatise Usage:
Ord.
Ending International Stage:
Hirnantian
Fraction Up In Ending Stage:
100
Ending Date:
443.07
Description
Apparatus multimembrate, composed of lamellar elements, P elements of two types, one angulate to bipennate, the other digyrate with posterior process strongly twisted out of plane of anterior process, both types with distinct cusp, multidenticulate processes, and basal cavity extending along entire length of processes, M elements geniculate, coniform, with anteriorly denticulate cusp and posteriorly extended base, S elements forming transition series from dolabrate through bipennate and tertiopedate to alate elements, All S elements with long, denticulate posterior process and basal cavity with prominent zone of recessive basal margin a short distance behind cusp, Denticles of variable size, laterally compressed, more or less confluent, those on posterior process a short distance behind cusp may rival cusp in size
References
Hadding, Assor, 1913, Undre dicellograptusskiffern i Skäne jämte några därmed ekvivalenta bildningar: Lunds Univ. Arsskr Avd. 2, v. 9, no. 15, p. 1-90, text-fig. 1-23, pl. 1-8.
Museum or Author Information
Classification
Phylum:
Conodonta
Class:
Conodonta
Order:
Conodontophorida
Superfamily:
Prioniodontacea
Family:
Periodontidae
Formal Genus Name and Reference:
Periodon HADDING, 1913, p. 33
Type Species:
P. aculeatus, M
Images
(Click to enlarge in a new window)
Fig. 76, 1. P. grandis (Ethington), M.Ord. (Prosser F.), USA (Minn.), 1a, c, two types of P elements, lat. views, X61, 1 b, M element, lat. view, X61, 1 d-f, three types of S clements, lat. views, X77, X 102, X 110 (Bergström, n)
Synonyms
Loxognathus; Falodus
Geographic Distribution
Ord., Eu.-N.Am.-S.Am.-Aus-tralia (N.Z.)
Age Range
Beginning Stage in Treatise Usage:
Ord.
Beginning International Stage:
Tremadocian
Fraction Up In Beginning Stage:
0
Beginning Date:
486.85
Ending Stage in Treatise Usage:
Ord.
Ending International Stage:
Hirnantian
Fraction Up In Ending Stage:
100
Ending Date:
443.07
Description
Apparatus multimembrate, composed of lamellar elements, P elements of two types, one angulate to bipennate, the other digyrate with posterior process strongly twisted out of plane of anterior process, both types with distinct cusp, multidenticulate processes, and basal cavity extending along entire length of processes, M elements geniculate, coniform, with anteriorly denticulate cusp and posteriorly extended base, S elements forming transition series from dolabrate through bipennate and tertiopedate to alate elements, All S elements with long, denticulate posterior process and basal cavity with prominent zone of recessive basal margin a short distance behind cusp, Denticles of variable size, laterally compressed, more or less confluent, those on posterior process a short distance behind cusp may rival cusp in size
References
Hadding, Assor, 1913, Undre dicellograptusskiffern i Skäne jämte några därmed ekvivalenta bildningar: Lunds Univ. Arsskr Avd. 2, v. 9, no. 15, p. 1-90, text-fig. 1-23, pl. 1-8.