Fact Zap

Dwarf Ancestor of Whales

Fossil bones recovered in Egypt show the smallest known ancestor of Whales. Named Tutcetus after the Egyptian pharaoh, Tutenkhamun, read what this discovery tells about pre-historic Whales and their adaptations.

Whale swimming underwater

Did you know that ancestors of modern day Whales were land animals ? Ancestors of the Hippopotamus were also land animals. Whales and Hippos come from a family of prehistoric animals that moved from land to water. Pre-historic animals called Basilosaurids were the first to become aquatic animals, leaving the land for good. Basilosaurids are ancestors of present day Whales.

Adaptations to water

Basilosaurids evolved to adapt to an aquatic life. Tall spine bones in the middle of their body and wide spine bones at the tail end helped them swim like experts. It shows they had paddle shaped tails. Fore arm bones were flexible and strong. They used it to propel themselves forward. Regardles of their big body size, they could change directions and flex themselve to swim well underwater. Back arms were of no use. As they evolved, it became small and disappeared completely.

Small Whales

Recent discovery of a Bassilosaurid fossil in Egypt showed surprising results. Whales and their ancestors have one thing in common, they were all huge in size. This fossil is the opposite. It is one of the smallest whale ancestors ever discsovered. At first, paleontologists thought it was a baby whale. But it had well grown adult teeth, proving the fully grown whale was small in size. This is the smallest known basilosaurid ever ! It is named Tutcetus rayanensis after the Egyptian child pharaoh Tutenkhamun.


Tutcetus (pronounced as tut-setus) whales are estimated to be 2.5 m (8 ft 4 in) long. It's weight is calculated around 180 kg (400 lb), which is less compared with other pre-historic whales. They lived in warm tropical waters close to Africa. This is one of the oldest known Basilosaurid fossils discovered yet. It shows not all prehistoric whales were big. They were different in size and weight, ranging from small to huge.