Day 171#: Casatia thermophila
Today's animal of the day is Casatia thermophila!
Image credit: A. Gennari
This species of extinct cetacean lived during the Early Pliocene epoch, between 5.1 and 4.5 million years ago, in what is now Italy. It's known from only fragmentary pieces of its skull, so not much is known about its appearance, but its closest living relatives are narwhals and belugas, so it probably looked similar to them. The presence of Casatia in the Mediterranean supports the theory that monodontids (the group consisting of belugas, narwhals, and several other extinct whales) first evolved in warmer climates before migrating north and adapting to colder waters. In addition to modern bull and tiger shark fossils, the remains of Casatia were found alongside a species of prehistoric dugong known as Metaxytherium subapenninum.