Walking on Seashells (and Penguins)
The latest stop on our search for penguins takes us to the Otekaike Limestone. This unit spans the Oligocene-Miocene boundary, with fossils dating to about 25 million years ago. Shells abound in the Otekaike Limestone – it is almost like walking along a never-ending high tide line after a storm.
Today’s trip yielded a few bits of penguin bone, including the base of a flipper and, more importantly from a scientific perspective, a whale skull bone. Each piece brings us closer to understanding what these extinct species were like. Even though the Otekaike Limestone is only a few million years younger than the Kokoamu Greensand, the penguins are much smaller and more modern looking. Comparing fossils from the two Formations is like viewing two frames of a film on penguin evolution, one taken a few moments after the other. Lots of other frames are missing, but the movie is still showing today in New Zealand, Antarctica, and everywhere else living penguins thrive.