The Eocene fishes of Monte Bolca: the earliest coral reef fish assemblage

Abstract

The fish assemblage from the Eocene deposits of Monte Bolca, Northern Italy, are compared with those of Recent coral reefs. A family-level taxonomic definition of a Recent coral reef fish assemblage is formulated to permit direct comparisons. On this basis, the Monte Bolca fishes represent the earliest clearly defined coral reef fish assem- blage. Quantitative analyses of the relative abundance of fish families revealed significant differences between the two assemblages. The Bolca assemblage has Mesozoic links (Pycnodontiformes) and non-perciform taxa are relatively abundant, particularly the Beryciformes (Holo- centridae). However, Bolca represents the earliest record of a perciform-dominated benthic fish assemblage (68.4% of all non-clupeid taxa). Within the Perciformes, the abun- dance of the major reef fish lineages (higher squamipinnes and Labroidei) differs markedly between the two assem- blages. The numerical dominance oflabroid fishes on coral reefs appears to have been a relatively recent occurrence.