Snapshots in Whale Evolution
The Charleston area holds a bounty of fossils of ancient marine fauna from invertebrates, fish, reptiles, whales to giant Ice Age behemoths like the giant ground sloth. The Charleston Museum possesses one of the most outstanding collections of locally-collected fossil cetaceans (whales, dolphins and porpoises) in the world, and many of these specimens represent new fossil genera and species that tell us much about whale evolution. As you make your way through this virtual exhibit, click on the interactive 3D models to learn more about each animal.
3D Interactive Controls
Orbit around: Left click + drag or One finger drag (touchscreen)
Zoom: Double click on model, scroll with mousewheel, or Pinch (touchscreen)
Pan: Right click + drag or Two fingers drag (touchscreen)
Snapshots in Whale Evolution
Many of the fossil cetaceans in The Charleston Museum collections are from three particular formations, or sediment layers present in the Lowcountry. Although other formations exist throughout the state these three produce the highest number of well preserved cetacean fossils along with other animals that once shared their ecosystem.
- The Tupelo Bay Formation – Many of the oldest whales in The Charleston Museum collection were excavated from the Tupelo Bay Formation, a sediment layer which dates to the middle Eocene and is approximately 37 – 40 million years old. Many of the cetaceans from this layer have characteristics we consider primitive in whales, such as blowholes close to the tip of their snout and hip bones.
- The Ashley Formation – Another marine sediment formation, the Ashley Formation is approximately 29 – 30 million years old. A diverse marine fauna has been excavated from this early Oligocene formation including sea turtles, dugongs, crocodiles, giant birds, and cetaceans.
- Chandler Bridge Formation – The Chandler Bridge Formation is a sediment layer that dates to the Late Oligocene Epoch approximately 25 – 28 million years ago. This formation underlies the Lowcountry, with known sites in Charleston, Berkeley, and Dorchester Counties. This layer, along with the Ashley, have produced a great number of new species of cetaceans. The Charleston area has one of the most diverse Oligocene whale fauna’s in the world and many of those found are housed in The Charleston Museum collections.
Critical Thinking Questions:
- How are the whale skulls in this virtual exhibit different from the Bottlenose dolphin in the previous exhibit?
- Tupelocetus has clues that suggest it had large jaw muscles. What would this mean for its feeding behavior compared to Rhabdosteus?
- Do you think these whales could use echolocation? Think back to the previous exhibit. Why or why not?
- Sediment – Any material carried by wind or water that is redeposited. This often includes sand, mud, and gravel.
- Fauna – A term meaing “animals.”
- Cetacean – the scientific term for whales.
- Dugongs – animals related to manatees. Dugongs are still around in other parts of the world, but extinct locally.
- Formation – a certain amount of rock layers that are similar in their composition and age.
- Eocene – a geologic epoch poch that lasted from about 56 to 33.9 million years ago.
- Oligocene – a geologic epoch of that lasted from about 33.9 million to 23 million years ago.
- Epoch – A division of time smaller than a period.