NMITA:Neogene Marine Biota of Tropical America



Hyporhamphus aff. unifasciatus (Ranzani, 1842)



Specimen details:
 Sample Number: PPP1528
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, becoming angular anteriorly;
    Dorsal margin: sharply rounded in juvenile to slightly rounded in adults, diagonal anteriorly;
    Ventral margin: slightly rounded and crenate to slightly irregular;
    Sulcus acusticus: ostial, heterosulcoid;
    Pseudocolliculum: absent;
    Colliculum: homomorph, a single, crystalline colliculum;
    Excisura: moderate, notch absent;
    Antirostrum: reduced;
    Rostrum: small and rounded;
    Ventral depression: absent;
    Dorsal depression: absent;
    Crista inferior: poorly developed along entire sulcus;
    Crista superior: poorly developed along entire sulcus;
    Collum: absent;
    Ostio-caudal differentiation: slight dorsal constriction;
    Cauda: approximately straight with a ventral flexion at tip, filled by the colliculum;
    Ostium: flared slightly dorsally, like an arrowhead;
    Posterior margin: slightly rounded and irregular;
    Dorsal margin sculpture: crenulated to irregular;
    Form: -Lateral slightly concave;
    Thickness: moderately thin;
    Form: -Mesial convex;
Distribution:
    Late Miocene: Tuira Fm., Darien, Panama;

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