NMITA:Neogene Marine Biota of Tropical America



Paralonchurus trinidadensis (Schwarzhans, 1993)



Specimen details:
 Sample Number: PPP2674
Type Status: nontype
Scale Bar is 1 mm
Type: SEM
Orientation: mesial
Locality: San Jose River, San Jose River, Trinidad

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Morphologic Description:

    Otolith shape: rectangular;
    Thickness: moderately thick;
    Form: -Mesial convex;
    Form: -Lateral slightly convex to flat;
    Dorsal margin: slightly rounded;
    Dorsal margin sculpture: slightly irregular;
    Ventral margin: slightly rounded and entire;
    Posterior margin: rounded and entire;
    Sulcus acusticus: ostial, heterosulcoid;
    Colliculum: heteromorph, low anterior and indistinct posterior colliculi;
    Pseudocolliculum: absent;
    Ostium: large, rectangular, inclined ventrally;
    Cauda: long and narrow, strongly bent; the tip is somewhat curved in the anterior direction close to ventral margin.;
    Ostio-caudal differentiation: dorso-ventrally constricted;
    Collum: absent;
    Crista superior: poorly developed over ostium, ridge-like over cauda;
    Crista inferior: poorly developed under ostium, moderately well developed under cauda;
    Dorsal depression: shallow and elongate;
    Ventral depression: absent;
    Rostrum: reduced;
    Antirostrum: rounded;
    Excisura: wide, notch absent;
Distribution:
    Middle Miocene: Manzanilla Fm., San Jose River, Trinidad;

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