Rare Monte Bolca Fossil Fish | Mene rhombea | Italy

Mene rhombea
Eocene (~50 MYO)
Bolca, Italy

Specimen dimensions: 15" x 8.3" x 0.8" (38 cm x 21 cm x 2 cm)
Specimen on stand dimensions: 19.1" x 9.8" x 7.9" (48.5 cm x 25 cm x 20 cm)
Specimen weight: 6.6 lbs / 3 kg
Specimen on stand weight: 17.6 lbs / 8 kg
Stand is included.

The specimen displays some characteristic features of Monte Bolca fish fossils, such as its delicate fin structures and the fish still clearly preserved in its stomach.

Mene rhombea is an extinct species of moonfish (family Menidae) known from the Eocene deposits of Monte Bolca, a world-famous fossil site in Italy. This species shares similarities with Mene maculata, the modern member of the genus Mene, which are still found in tropical Indo-Pacific waters today.

Mene rhombea exhibits a distinctive deep, laterally compressed body with a nearly circular or rhomboidal shape, which is a characteristic feature of the Menidae family. The highly compressed body suggests maneuverability rather than sustained speed, making it well-suited for navigating reef or seagrass environments. As suggested by its small, upturned mouth, and by comparison to its living relative Mene maculata, Mene rhombea likely fed on on plankton and small invertebrates.

Monte Bolca was part of a shallow marine lagoon system during the early Eocene (~50 million years ago), with warm, tropical conditions. The rich diversity of fish fossils found at this site suggests that Mene rhombea lived in a reef environment, similar to its modern relative.

Monte Bolca is a Lagerstätten deposit, so fossils here are often found highly preserved with exceptional detail. Anatomical structures such as fin rays, scales, and even gut contents in some specimens have been observed. This suggests rapid burial in low oxygen conditions, which prevented decomposition and scavenging.