 When you can see fossils in the stone, it's a pretty good guess that it's some type of limestone. Chris is quite the dichotomy. Corporate attorney by day, Indiana Jones fedora-wearing paleontology enthusiast by night. And whether we stopped into Gallery One to take in 400 million-year-old nautiloid remains on the floor underneath the famous Madonna and Child painting. It was part of the shell of a squid-like animal.