That appears the starter gear broke off and is probably wedged against the flex plate. Maybe you can get a friend with a 1/2' drive ratchet and 19mm socket on the crank bolt and turn the engine a bit in both directions to see if you can wiggle that starter gear free of the flex plate. Next, you can take the inspection plate off the bottom of the bell housing and have your buddy turn the engine clockwise while you're inspecting the flex plate teeth for any damage.