Osteolepis is a small, lobe-finned fish, that grew to about 20 cm long. Its body was covered with large square scales that were covered in a layer of spongy bony material called cosmine (Mondéjar-Fernández, 2018). Pores in this spongy layer were connected to sensory cells in the skin, probably enabling the fish to detect movement in the water (Mondéjar-Fernández, 2018). Osteolepis is fairly common in the Devonian rocks of the Orcadian Basin of Scotland (Newman, 2010), and the genus has also been reported from the United States (Paleobiology Database, n.d.). Osteolepis has not been found in sediments above Devonian strata.

References:

Mondéjar-Fernández, J., (2018). On cosmine: its origins, biology and implications for sarcopterygian interrelationships. Cybium, 42(1), pp. 41-65.

Newman, M., (2010) Middle Devonian Fish from the Orcadian Basin of Scotland. International Palaeontological Congress 3 Pre-conference Field Trip, London, pp. 54-58.

Paleobiology Database (no date) Osteolepis, The Paleobiology Database. Available at: https://paleobiodb.org/classic/basicTaxonInfo?taxon_no=34888 (Accessed: August 2024).