NMITA:Neogene Marine Biota of Tropical America

Membras sp.1

Specimen details:
Sample Number: PPP1997
Type Status: nontype
Scale Bar is 1 mm
Type: SEM
Orientation: mesial
Locality: Darien, Darien, Panama

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Morphologic Description:

    Otolith shape: oval;
    Dorsal margin: rounded, emarginated posteriorly;
    Ventral margin: slightly rounded and irregular;
    Sulcus acusticus: ostial, heterosulcoid;
    Pseudocolliculum: absent;
    Colliculum: heteromorph, two distinctly different colliculi;
    Rostrum: short and slightly pointed;
    Ventral depression: absent;
    Dorsal depression: absent;
    Crista inferior: poorly developed under ostium, moderately well developed under cauda;
    Crista superior: poorly developed over ostium, moderately well developed over cauda;
    Collum: absent;
    Ostio-caudal differentiation: dorso-ventrally constricted;
    Cauda: long, narrow, slightly flexed ventrally, except in the tip that is curved dorsally;
    Excisura: moderately narrow;
    Antirostrum: short and rounded;
    Ostium: short, discoid, expanded dorsally;
    Posterior margin: flattened to rounded and irregular;
    Dorsal margin sculpture: irregular;
    Form: -Lateral slightly concave;
    Thickness: thin;
    Form: -Mesial slightly convex;
    Late Miocene: Tuira Fm., Darien, Panama;

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