Osteolepis Devonian Fish Fossils
"an ancient tetrapod ancestor"

Description: This is a double specimen plate of these rare Paleozoic fossil fish from a famous Scottish site. The primary specimen is complete, and both fishes show their rhombic scales in good detail. The Osteolepiform fish are thought to be the ancestors of the Tetrapoda due to their paired lobed fins being homologous to the limbs, and the choanae (posterior nostril). Osteolepis possessed two rounded dorsal fins placed posteriorly, and a heterocercal tail with a larger lower lobe. They have thick rhombic scales covered with a cosmine layer (hence the shine). This ancient group of fish is thought to have given rise to the Tetrapod bauplan.

Also see: Sarcopterygii Fish Fossils