NMITA:Neogene Marine Biota of Tropical America



Hygophum macrochir (Gunther, 1864)



Specimen details:
 Sample Number: PPP3055
Type Status: nontype
Scale Bar is 1 mm
Type: SEM
Orientation: mesial
Locality: Araya, Araya, Venezuela

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Morphologic Description:

    Otolith shape: discoid, becoming slightly angular posteriorly;
    Posterior margin: rounded and slightly irregular;
    Ventral margin: well rounded anteriorly and irregular;
    Crista inferior: low ridge under posterior ostium, poorly developed elsewhere;
    Crista superior: low ridge from ostium to cauda, absent at cauda tip;
    Collum: absent;
    Ostio-caudal differentiation: slightly ventrally constricted;
    Cauda: short and oblong;
    Ostium: approximately oblong with oblong colliculum;
    Pseudocolliculum: present, ridge-like;
    Colliculum: heteromorph, larger anterior colliculum;
    Excisura: moderate, notch shallow, angle acute;
    Antirostrum: short and sharply rounded;
    Rostrum: short, broad and sharply rounded;
    Ventral depression: small, oval and shallow under cauda, very shallow groove in mid-area;
    Dorsal depression: shallow and oval;
    Sulcus acusticus: ostial, heterosulcoid;
    Thickness: moderate;
    Form: -Lateral slightly convex;
    Dorsal margin: slightly rounded, angled toward rostrum, emarginated posteriorly;
    Dorsal margin sculpture: irregular;
    Form: -Mesial slightly convex;
Distribution:
    Early Pliocene: Cubagua Fm., Araya, Venezuela;

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