When I first started in the fossil hunting hobby, I found (on land) a mammal inner ear --- I know it is a Llama inner ear because I found an exact duplicate labeled as such on the internet -- better than nothing, I guess. http://www.thefossil...-ear-but-whose/ Includes photos
Harry Pristis was the only responder and gave me some good advice on "mammal inner ears" which likely still applies.
Lo and Behold, I have ANOTHER mammal inner ear found yesterday, approximately the same size, but it is v