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Pragnellia

Classification

    Phylum:  
Cnidaria
    Class:  
Anthozoa
    Subclass:  
Tabulata
    Order:  
Heliolitida
    Suborder:  
Heliolitina
    Superfamily:  
Coccoseridicae
    Family:  
Coccoseridicae - Family uncertain
    Formal Genus Name and Reference:  
Pragnellia LEITH, 1952, p. 794
    Type Species:  
P. arborescens; M; +429P, Manitoba Museum, Winnipeg. [For discussion of systematic position see BONDARENKO, 1969, p. 105. LIN in LIN & CHOW, 1977, p. 193, included Pragnellia together with a new family Sibiriolitidae LIN in a new order of Tabulata, Pragnellida LIN.]


Images

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Fig. 427,la-c. ·P. arborescens, holotype, Manit., Stony Mountain; a, transv. sec. internode, X3.8, b,c, ext. views, X4.7, X0.3 (Leith, 1952).


Synonyms



Geographic Distribution

N. Am. (Manit.-?Texas)-Eu.(W. slope of Urals-?Ire.)


Age Range

    Beginning Stage in Treatise Usage:  
U. Ord.(Richmond.)
    Beginning International Stage:  
Katian
    Fraction Up In Beginning Stage:  
66.7
    Beginning Date:  
447.72
    Ending Stage in Treatise Usage:  
U.Ord.(Richmond.)
    Ending International Stage:  
Katian
    Fraction Up In Ending Stage:  
100
    Ending Date:  
445.21


Description

Polyparium branching by dichotomy, branches of internodes of calcareous skeletal elements and nodes that were not calcareous, possibly proteinous, internodes phalangoid, with 'corallites' lacking distinct walls surrounded by common tissue of loosely packed, prickly rods perpendicular to surface; neither septa nor tabulae noted, but barlike connections are found between rods of common tissue; 'corallites' almost completely filled with sclerenchyme. [Alternation within the branches of calcareous internodes with ?horny nodes recalls that in members of octocorallian Isididae also (see BAYER, 1956b, p. F222), the microstructure of the calcareous parts of the branches is very similar to that of octocorallian Helioporidae. Perhaps Pragnellia is an alcyonarian.]




References

Leith, E. I., 1952, Schizocoralla from the Ordovician of Manitoba: J. Paleontol., v. 26, p. $789-$ 796, pl. 114-116.


Museum or Author Information