A flatfish is a member of the ray-finned demersal fish order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward.
Monte Bolca is a lagerstätte near Verona, Italy that was one of the first fossil sites with high quality preservation known to Europeans, and is still an important source of fossils from the Eocene.
Amphistium paradoxum, the only species classified under the genus Amphistium and the family Amphistiidae, is a fossil fish which has been identified as a Paleogene relative of the flatfish, and as a transitional fossil. In a typical modern flatfish, the head is asymmetric with both eyes on one side of the head. In Amphistium, the transition from the typical symmetric head of a vertebrate is incomplete, with one eye placed near the top of the head.
Ceratoichthys is an extinct genus of lookdown-like prehistoric jackfish that lived during the late Ypresian epoch, of the Early Eocene. It contains a single species, C. pinnatiformis of Monte Bolca, Italy. It and Vomeropsis are the only known members of the extinct subfamily Vomeropsinae.
Eobuglossus is an extinct genus of marine flatfish that lived during the Eocene. It contains a single known species, E. eocenicus, known from the late Lutetian-aged Mokattam Formation of Egypt, with its fossils recovered from the historically important Tura quarry.
Eoaulostomus is an extinct genus of marine ray-finned fish, closely related to the modern trumpetfish, that lived during the Eocene. It contains two species, E. bolcensis(de Blainville, 1818) and E. gracilisBlot, 1981, both known from the Early Eocene-aged Monte Bolca site of Italy.
Anguilloides is an extinct genus of prehistoric marine eel that lived in the early Eocene. It contains a single species, A. branchiostegalis. Fossils are known from the famous Monte Bolca site of Italy.
Bolcyrus is an extinct genus of prehistoric marine eel that lived during the Early Eocene. It was a member of the family Congridae, which also contains modern conger eels.
Eoanguilla is an extinct genus of prehistoric marine eel that lived during the early Eocene. It contains a single species, E. leptoptera from the Ypresian-aged Monte Bolca site of Italy. It is thought to have been an early marine relative of the modern freshwater eels.
Ductor is an extinct genus of prehistoric marine ray-finned fish that lived during the early Eocene. It contains a single species, D. vestenae, known from the famous Monte Bolca site of Italy. It is the only member of the family Ductoridae. It is the earliest representative of the suborder Echeneoidei, and is thought to be most closely related to cobias and dolphinfish.
Acanthonemus is an extinct genus of prehistoric marine ray-finned fish that lived from the early Eocene. It contains a single species, A. subaureus, known from the famous Monte Bolca site in Italy. It is the only genus in the extinct family Acanthonemidae.
Coelogaster is an extinct genus of marine ray-finned fish that lived during the early Eocene. It contains a single species, C. leptostea, known from the famous Monte Bolca site of Italy.
Callipteryx is an extinct genus of prehistoric marine trachiniform fish that lived during the early Eocene. It is the only known member of the extinct family Callipterygidae. It is thought to have been a relative of weeverfishes.
Carangopsis is an extinct relative of the bluefish that lived during the early Eocene. It contains two species, both from the famous Monte Bolca site of Italy.
Carangodes is an extinct genus of prehistoric ray-finned fish that lived during the early Eocene. It contains a single species, C. bicornis, from the famous Monte Bolca site in Italy. It is the only known member of the extinct perciform family Carangodidae.
Sparnodus is an extinct genus of prehistoric perciform fish in the family Sparidae. Species of this genus were nektonic carnivores. These fishes lived in the Cenozoic Era, in the Oligocene and Paleocene.
Platinx is an extinct genus of marine ray-finned fish that inhabited the northern Tethys Ocean during the early to middle Eocene. It was the last surviving member of the ancient order Crossognathiformes, which was a dominant and successful group throughout the preceding Mesozoic era.
Palimphyes is an extinct genus of marine ray-finned fish known from the Paleogene period. It was a euzaphlegid, an extinct family of scombroid fish related to the escolars and snake mackerels.
Cyclopoma is an extinct genus of marine perciform fish from the Eocene. It is known from the Ypresian to the Lutetian of Europe and eastern North America.
The Eocene-aged Monte Bolca fossil site near Verona, Italy was one of the first lagerstatte to be discovered to science, and still has one of the most prominent vertebrate faunas of all Cenozoic lagerstatte. It has the highest fish diversity of all known Cenozoic fossil sites, with many fossils having extremely detailed preservation. In addition, a very high diversity of marine invertebrates & land plants and a small number of land vertebrates are also known.
