This is an alligator (mississippiensis) leg bone (humerus) that was found in the Peace River (Hardee County, Bone Valley, Hawthorn Group, Florida). The specimen was found in an area with rich Pliocene and Pleistocene (11,000 to 5,000,000 years old) deposits. It is partially-fossilized, so it is not recent, but it is not many thousands of years old - it's somewhere in between. The bone is in very good condition (solid, nice coloration, no damage) and measures approx. 5 inches long x 2 inches wide. (125mm x 50mm).
Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing the specimen shown.