answers: Dimetrodon
context: Cephalopod limb All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. In the scientific literature, a cephalopod "arm" is often treated as distinct from a "tentacle", though the terms are sometimes used interchangeably. Generally, arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends. Barring a few exceptions, octopuses have eight arms and no tentacles, while squid and cuttlefish have eight arms (or two "legs" and six "arms") and two tentacles. The </s> Tetrapodophis Tetrapodophis (meaning "four-footed snake" in Greek) is an extinct genus of snake from the Early Cretaceous of Brazil. It is one of the oldest snakes and the only known snake with four legs. "Tetrapodophis" possesses small yet well-developed fore- and hindlimbs, a feature found in no other snake living or extinct. Nevertheless, it shares many characteristics with modern snakes, including an elongate body, short tail, broad belly scales, a skull with a short snout and long braincase, curved jaws, and sharp hooked teeth. BMMS BK 2-2 contains bones of another animal in its gut, indicating that "Tetrapodophis" was carnivorous </s> debated. A thermoregulatory role seems unlikely, although the taller crest in "Sphenacodon ferocior" is allometrically larger than in "S. ferox". Recent research has favored a display role for the tall sails in "Dimetrodon" and "Edaphosaurus". Both "Sphenacodon" and "Dimetrodon" have been depicted with their short limbs splayed outward at 90 degrees from the body in a wide pushup position and with the tail (and even belly) dragging on the ground, similar to modern lizards and crocodiles. A sprawling stance is also typical for "Sphenacodon" and "Dimetrodon" skeletons as currently mounted in museums. However, trackways called "Dimetropus" (“"Dimetrodon" foot”) that match
question: dinosaur with fin on back walks on 4 legs