A studied of the Lower Miocene fish fauna of the Pacuare de Tres Equis locality is made. In this area it is recorded 8 genera of sharks: <span name="style_italic">Heptranchias, Megaselachus, Isurus, Carcharias, Mitsukurina, Hemipristis, Negaprion</span> and <span name="style_italic">Carcharhinus</span>; and 6 families of osteichthyans, Sparidae, Acanthuridae, Scaridae, Labridae, Sphyraenidae and Tetraodontidae. This fish assemblage points out to infralittoral-neritic, tropical warming waters environments with normal salinity.; and 6 families of osteichthyans, Sparidae, Acanthuridae, Scaridae, Labridae, Sphyraenidae and Tetraodontidae. This fish assemblage points out to infralittoral-neritic, tropical warming waters environments with normal salinity.

Formación Río Banano; Mioceno Inferior; Heptranchias; Mitsukurina; Carcharhinidae; Scaridae; Costa Rica