stemtetrapods
Stem tetrapods represent a paraphyletic group of extinct sarcopterygian (lobe-finned) fishes that lived from the Devonian period onwards. They are considered ancestral to tetrapods, the group that includes all four-limbed vertebrates, but they themselves did not possess true limbs in the tetrapod sense. Instead, they had pectoral and pelvic fins that were more robust and muscular than those of their fish ancestors, featuring internal skeletal structures that foreshadowed the limb bones of later tetrapods.
These fins were likely used for maneuvering in shallow water, pushing off the substrate, and possibly for
Key fossils that represent stem tetrapods include species like Tiktaalik, which exhibits a unique combination of