NMITA:Neogene Marine Biota of Tropical America



Trachurus sp.1



Specimen details:
 Sample Number: PPP2164
Type Status: nontype
Scale Bar is 1 mm
Type: SEM
Orientation: mesial
Locality: Canal, Canal, Panama

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Morphologic Description:

    Otolith shape: oval to elongate;
    Thickness: moderately thin;
    Form: -Mesial slightly convex;
    Form: -Lateral concave;
    Dorsal margin: slightly rounded;
    Dorsal margin sculpture: sinuate;
    Ventral margin: slightly rounded and crenate;
    Posterior margin: sharply rounded and crenulate or irregular;
    Sulcus acusticus: ostial, heterosulcoid;
    Colliculum: heteromorph, low anterior and indistinct posterior colliculi;
    Pseudocolliculum: absent;
    Ostium: short and oval;
    Cauda: straight and narrow, strongly flexed and deepening at tip, ending close to margin where it may have a narrow canal to margin;
    Ostio-caudal differentiation: dorso-ventrally constricted;
    Collum: absent;
    Crista superior: well developed over ostium, ridge-like along cauda, well developed after flexion;
    Crista inferior: ridge-like bellow sulcus;
    Dorsal depression: shallow;
    Ventral depression: absent;
    Rostrum: short and sharply rounded;
    Antirostrum: minute or small and rounded;
    Excisura: moderate tomoderately wide, notch very shallow, angle wide;
Distribution:
    Middle Miocene to Late Miocene: Gatun Fm., Canal, Panama;

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