Cheirolepis and Osteolepis

Date: 2009
Medium: acrylics on card/digital

Middle Devonian (Eifelian-Givetian), Scotland

Cheirolepis trailli of the famous Old Red Sandstone fish beds of Scotland represents the earliest, and in many ways the most primitive, undisputed ray-finned fish in the fossil record. It was a chunky freshwater predator that retained fleshy pectoral lobe-fins. In the background are a pair of Osteolepis macrolepidotus, small basal tetrapodomorph fishes.

Back in the Devonian, ray-finned fishes (actinopterygians) were the "new kids on the block" with fewer than 20 well known species compared with over 200 lobe-finned fishes (sarcopterygians). Now they are the most speciose vertebrates on the planet with over 28,000 species (vs a pitiful 7 non-tetrapod lobe-fins)