An enigmatic teleost fish from the Eocene of Bolca (Italy) with unusual larval-like features

‘Pegasus’ volans is a highly unusual fossil teleost fish from the celebrated Eocene Bolca Lagerstatte. The fossil, known on the basis of two specimens, has been historically assigned to seamoths (Pegasidae), then to oarfishes and relatives (Lampriformes). We describe its enigmatic skeletal anatomy in detail and provide a new genus name: †Dibango. †Dibango volans is an extremely elongate and slender animal, with long anal and dorsal fins and a very well-developed first dorsal-fin ray reminiscent of the vexillum of some modern teleost larvae. Most striking is its extreme ventral projection of the pelvic bone (basipterygium), associated with an element of the pectoral girdle (a long process of the coracoid) and developed pelvic-fin rays. The strongly reduced abdominal region suggests that †D. volans had an external gut, once again reminiscent of those of certain larval teleosts. The unique character state combination of †D. volans makes it impossible to assign it to a specific subclade within perch-like spiny-rayed fishes (Percomorpha). Nevertheless, it offers a valuable perspective on the diversity of morphologies and ecological niches occupied by teleost fishes of the early Eocene Bolca fauna.