Mystacodon facts for kids

Mystacodon is an ancient type of whale. It lived about 36 million years ago. This whale had teeth, which is interesting because most modern baleen whales don't. Scientists found its fossils in Peru. Mystacodon is the oldest known baleen whale. It likely ate small creatures from the ocean floor by sucking them up.

Discovering Mystacodon

Mystacodon is the oldest known baleen whale. Its fossils date back 36.4 million years. This time was the late Eocene period. The main fossil found is called a holotype specimen. It includes parts of the whale's skull, teeth, and bones from its spine, fins, and hip. This special fossil is kept at the Museum of Natural History in Lima, Peru.

What's in a Name?

The name Mystacodon comes from ancient Greek words. Mystacos means "moustache" and odontos means "tooth". The "moustache" part refers to Mysticeti. This is the group of whales that have baleen plates instead of teeth. The species name, selenensis, comes from Selene. She was the Greek goddess of the moon. This name was chosen because the fossil was found at a place called Playa Media Luna. This means "Half Moon Beach" in Spanish.

What Mystacodon Looked Like

Mystacodon was about 3.75 to 4 meters (12 to 13 feet) long. This is quite large for an ancient whale. Its snout was much flatter than older whale types. Its nostrils were also placed higher up on its head. This flat snout suggests it didn't use its front teeth for grasping food. The longer head probably helped it open its mouth wider.

Teeth and Eyes

Scientists are not sure if Mystacodon had any baleen in its mouth. Unlike older whales, it didn't have a ridge on its head. This ridge is usually for strong biting muscles. Mystacodon's eye sockets were larger. They also faced more forward and were slightly higher up. Its back teeth, called premolars and molars, had two roots.

Bones and Movement

The upper arm bone (humerus) of Mystacodon was long. It was about the same length as its shoulder blade. This is like modern slow-moving whales. Its arm muscles might have been constantly flexed. This is unusual for whales. It might have helped it move along the seafloor. It could also have helped it stay in one place in the water. Its hip bones were similar to even older whales. They had a short upper hip bone (ilium) and a clear hip joint.

How Mystacodon Ate

Mystacodon was likely a suction feeder. This means it ate by sucking in its prey. This way of eating was a step in whale evolution. Older whales hunted their prey. More modern baleen whales filter feed. Mystacodon probably ate small creatures from the ocean bottom.

What It Ate

Scientists found some interesting things near the Mystacodon fossil. They found a stinger from an eagle ray. They also found scales from small fish like herring, sardines, and anchovies. It's possible that Mystacodon might have eaten eagle rays.

See also

In Spanish: Mystacodon para niños