Eocene Emergence of Modern Reef Communities
8th March 2008

Here in the warm sea of Oman a great variety of reef-associated fish and invertebrates can be observed. Fossils of remarkably similar forms can be found in the Eocene limestones exposed along the coast near Muscat. These include a diversity of corals, echinoids, molluscs and forams.

The most celebrated exceptionally preserved marine fauna of this age is that of Monte Bolca in northern Italy (Middle Cuisian, Early Eocene, Trevisani et al. 2005). The spectacular fish fauna found here has been described as the earliest clearly defined coral reef assemblage (Bellwood 2005). The fish fossils are associated with crustaceans, worms, and plants. The fossils represent mass kills resulting from algal blooms and the associated toxicity. We see this in Omani coastal waters every summer during upwelling events and sometimes later in the year (such as yesterday, 12/11/08).

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Moonfish, Mene rhombeata Volta (1796), an Actinopterygian fish (Order: Perciformes; Family: Menidae), length 12.5 cm. Early Eocene. Monte Bolca, northern Italy. This is the iconic symbol of the Monte Bolca fish beds. Mene is known to school (Lee et al., 1988) and is often found near the bottom, where it feeds primarily on copepods, shrimp, and fish larvae (Luo, 1982).” Here in Oman we have Mene maculata.
Moonfish, Mene rhombeata Volta (1796), an Actinopterygian fish (Order: Perciformes; Family: Menidae), length 12.5 cm. Early Eocene. Monte Bolca, northern Italy. This is the iconic symbol of the Monte Bolca fish beds. Mene is known to school (Lee et al., 1988) and is often found near the bottom, where it feeds primarily on copepods, shrimp, and fish larvae (Luo, 1982).” Here in Oman we have Mene maculata.
 A cardinalfish, Apogon spinosus, 33 mm long with seagrass on 10 x 9 cm matrix. Early Eocene. Monte Bolca, northern Italy. Cardinalfishes are nocturnal. During the day they mostly hide in crevasses and under ledges whereas at night they feed on zooplankton. Most cardinalfish species are mouth brooders, this role being performed by the male.
A cardinalfish, Apogon spinosus, 33 mm long with seagrass on 10 x 9 cm matrix. Early Eocene. Monte Bolca, northern Italy. Cardinalfishes are nocturnal. During the day they mostly hide in crevasses and under ledges whereas at night they feed on zooplankton. Most cardinalfish species are mouth brooders, this role being performed by the male.
 Similar to seamoths, robust ghostpipefish and short dragonfish in the modern seas, these are opportunistic feeders that collect mainly epifaunal and interstitial invertebrate prey such as crustaceans and worms from the sediment-water interface. This is Ramphosus aculeatus, a fabulously rare teleost fish fossil (Order: Syngnathiformes; Family: Ramphosidae), 58 mm long from the Early Eocene of Monte Bolca, northern Italy.
Similar to seamoths, robust ghostpipefish and short dragonfish in the modern seas, these are opportunistic feeders that collect mainly epifaunal and interstitial invertebrate prey such as crustaceans and worms from the sediment-water interface. This is Ramphosus aculeatus, a fabulously rare teleost fish fossil (Order: Syngnathiformes; Family: Ramphosidae), 58 mm long from the Early Eocene of Monte Bolca, northern Italy.
Barracudas are at the top of the coral reef food pyramid. This is Sphyraena bolcensis, a 15 cm juvenile barracuda from the Early Eocene of Monte Bolca, northern Italy.
Barracudas are at the top of the coral reef food pyramid. This is Sphyraena bolcensis, a 15 cm juvenile barracuda from the Early Eocene of Monte Bolca, northern Italy.
Squilla antiqua, 25 mm mantis shrimp. Early Eocene. Monte Bolca, northern Italy.
Squilla antiqua, 25 mm mantis shrimp. Early Eocene. Monte Bolca, northern Italy.
Small prawn, Penaeus bolcensis, 24 mm long with seagrass blades. Early Eocene. Monte Bolca, northern Italy.
Small prawn, Penaeus bolcensis, 24 mm long with seagrass blades. Early Eocene. Monte Bolca, northern Italy.
 Seagrass (Cymodocea sp) encrusted with epibionts in the form of tiny gastropods. Early Eocene. Monte Bolca, northern Italy.
Seagrass (Cymodocea sp) encrusted with epibionts in the form of tiny gastropods. Early Eocene. Monte Bolca, northern Italy.
 Annelids like this are commonly predated upon by corals in modern reefs. This one is roughly 200 mm along its axis. Early Eocene. Monte Bolca, northern Italy. Associated with leaves up to 140 mm long.
Annelids like this are commonly predated upon by corals in modern reefs. This one is roughly 200 mm along its axis. Early Eocene. Monte Bolca, northern Italy. Associated with leaves up to 140 mm long.
An imagined Eocene marine scene with cast of characters from Monte Bolca and Oman (my first and only attempt at an oil painting!).
An imagined Eocene marine scene with cast of characters from Monte Bolca and Oman (my first and only attempt at an oil painting!).
 Nautilus, gastropods and echinoids from the Middle Eocene Seeb Formation, near Muscat, Oman. The large echinoid at the back measures approximately 10 cm.
Nautilus, gastropods and echinoids from the Middle Eocene Seeb Formation, near Muscat, Oman. The large echinoid at the back measures approximately 10 cm.
 Coral (Dendrophyliidae), 6 cm, from the Middle Eocene Seeb Formation, near Muscat, Oman.
Coral (Dendrophyliidae), 6 cm, from the Middle Eocene Seeb Formation, near Muscat, Oman.
 Goniopora websteri, 65 mm, Marsh Farm Formation, Eocene, at Bracklesam Bay, West Sussex, England.
Goniopora websteri, 65 mm, Marsh Farm Formation, Eocene, at Bracklesam Bay, West Sussex, England.
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