In the late 18th century a strange fish fossil from the Monte Bolca deposits in northern Italy was described and named as Pegasus volans. This name had actually already been assigned to the living longtail seamoth (today known as Pegasus volitans), but despite this the fossil continued to be referred to as “Pegasus volans” for well over 200 years.
Now, finally, it’s been redescribed and given a proper genus name of its own: Dibango volans.
Living during the early Eocene, around 50-48 million years ago, in what was then a warm shallow reef in the western Tethys Ocean, Dibango was probably around 7-10cm long (~3–4″). It had a long flag-like first ray of its dorsal fin, a very reduced and compact abdominal region, an extremely elongated pelvic bone that appears to have supported an exterilium (external gut), long pelvic fins, and a long slender tail.
This bizarre combination of features is often seen in fish larvae, but Dibango’s level of skeletal development shows it was fully grown – suggesting it was actually an unusually neotenic fish, retaining its larval anatomy all the way into adulthood.
This also makes it very difficult to figure out what kind of fish it actually was, with the current best guess being “some sort of percomorph“.
References:
- Davesne, Donald, and Giorgio Carnevale. “An enigmatic teleost fish from the Eocene of Bolca (Italy) with unusual larval‐like features.” Papers in Palaeontology 11.3 (2025): e70017. https://doi.org/10.1002/spp2.70017
- Volta, Giovanni Serafino, et al. “Ittiolitologia veronese del Museo Bozziano: ora annesso a quello del Conte Giovambattista Gazola e di altri gabinetti di fossili veronesi; con la versione latina.” Verona, Italy: Dalla Stamperia Giuliari (1796). https://www.biodiversitylibrary.org/bibliography/163554
- Wikipedia contributors. “Dibango volans” Wikipedia, 20 May 2025, https://en.wikipedia.org/wiki/Dibango_volans