Whatcheeria facts for kids

Whatcheeria was an ancient animal that lived a very long time ago, about 340 million years ago! It was an early tetrapod, which means it was one of the first animals with four limbs that could walk on land, even though it still spent time in water. Scientists found its fossils in an old limestone quarry in Delta, a town in Iowa, USA. The only known species is W. deltae, named in 1995. Whatcheeria belongs to a group called Whatcheeriidae, which also includes a similar animal called Pederpes.

Whatcheeria's Body Features

Whatcheeria had a mix of old and new features. Some of its traits were "basal," meaning they were like those of its ancient ancestors, the lobe-finned fish. Other traits were "derived" or "advanced," meaning they were newer features that helped it adapt.

Fish-like Traits

Like its fish ancestors, Whatcheeria had special lines on its skull called lateral lines. These lines helped it sense movements and vibrations in the water, just like fish do today. It also had rows of teeth on the roof of its mouth, called the palate, which is another feature from its fishy past.

Moving to Land

Whatcheeria had a bone called a cleithrum. This bone is part of its shoulder area, known as the pectoral girdle. In its fish ancestors, the cleithrum was connected to the skull. But in Whatcheeria, this bone was separate. This separation was a big step! It allowed Whatcheeria to move its neck freely, which is very important for animals living on land.

Skull and Size

Whatcheeria could grow to be about 1 metre (3.3 ft) long, which is about the size of a small person. Its skull was quite deep, which was an advanced feature. It also had a pointed snout. On the top of its skull, behind its eyes, there was a fairly large hole called the parietal foramen. The bones on the surface of its skull were unusually smooth. Many other early tetrapods had skulls with rough, pitted surfaces.

How Scientists Classify Whatcheeria

Scientists use a method called cladistics to understand how different animals are related. When they classify Whatcheeria, they don't place it into a group like Amphibia (which includes frogs and salamanders). Instead, they simply put it in its own family, Whatcheeriidae, within the larger group of Tetrapoda. This means its exact family tree with other early tetrapods is still a bit unclear, but it's definitely one of the very first four-limbed animals.

See also

• In Spanish: Whatcheeria para niños

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