How much higher or lower was the sea level in the early Pliocene compared to today ?
( Late Miocene / Early Pliocene of Lee Creek Mine , USA ) - possibly " A. stewarti " " Alca stewarti " ( Kattendijk Sands Early Pliocene of Belgium ) " Alca ausonia " ( Yorktown Early Pliocene of Lee Creek Mine , USA - Middle Pliocene of Italy ) " Alca " sp.