Jump to content
  • Periarchus sp.


    sixgill pete


    Sand Dollar

    Kingdom: Animalia
    Phylum: Echinodermata
    Class: Echinoidea
    Order: Clypeasteroida
    Family: Protoscutellidae
    Genus: Periarchus
    Species: P. sp.
    Author Citation Conrad, 1866

    Geological Time Scale

    Eon: Phanerozoic
    Era: Cenozoic
    Period: Paleogene
    Epoch: Eocene
    Age: Bartonian


    Castle Hayne Formation


    Collector: Don Rideout
    Date Collected: 03/18/2016
    Acquired by: Field Collection


    Length: 30mm
    Width: 28.2mm
    Thickness: 5.1mm


    Martin Marietta Quarry
    Onslow County
    North Carilina
    United States


    Periarchus sp. is found in Zullo & Harris (1987) sequence 3 of the Castle Hayne Formation ( Kier, (1980) middle biozone). It is differentiated from Periarchus lyelli only by the placement of the periproct. In P. sp the periproct is below the midpoint between the peristome and the posterior margin of the test. On P. lyelli it is slightly above. Kier (1980), identified this sand dollar as Protoscutella plana; however Osborne, Mooi and Ciampaglio (2013) determined the oral plate structure separate these specimens from Protescutella plana and belonged in the Genus Periarchus. 

    User Feedback

    There are no comments to display.

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now