Pachydermata facts for kids

Animals often called pachyderms: hippos, rhinos, tapirs, and elephants.

Pachydermata (say "pak-ee-DER-mah-tuh") is an old way of grouping certain mammals. The word comes from ancient Greek and means "thick skin." For a long time, scientists used this term to describe animals like elephants, rhinoceroses, hippopotamuses, and tapirs. However, modern studies of animal DNA (their genetic code) show that these animals are not as closely related as once thought. Because of this, "Pachydermata" is no longer used as a scientific classification today. But people still often use the word pachyderm to describe these large, thick-skinned animals.

What are Pachyderms?

The term Pachydermata was a scientific order (a group of animals) that is now considered outdated. It was first described by scientists like Gottlieb Storr and Georges Cuvier. They grouped animals based on how they looked and their body features.

Georges Cuvier, a famous scientist, defined pachyderms as "animals with hoofs, not ruminants." Ruminants are animals that chew their cud, like cows. Storr described them as "mammals with hoofs with more than two toes."

The animals originally placed in the Pachydermata group were all plant-eaters. This group included:

• Proboscidea: This group now only includes the three types of elephants.
• Perissodactyla: These are "odd-toed ungulates." This means they have an odd number of toes on each foot. Examples include horses, tapirs, and rhinoceroses.
• Suina: This group includes pigs and peccaries.
• Hippopotamidae: This group includes hippopotamuses.
• Hyracoidea: These are hyraxes, which are small, furry mammals.
• Sirenians: This group includes manatees and dugongs, which are sea mammals.

Even though the Pachydermata group is no longer used in science, it was important in the history of how we classify animals. Many well-known zoologists, including Charles Darwin, recognized it as a group of hoofed mammals.

History of the Classification

In 1796, Georges Cuvier first created the classification of Pachydermata. He even added horses to this group.

Today, thanks to genetic studies (which look at an animal's DNA), we know that the animals once called pachyderms are actually part of different main groups, called clades.

• Rhinos, hippos, pigs, peccaries, horses, zebras, donkeys, and tapirs are now in a large group called Laurasiatheria.
• Elephants, hyraxes, manatees, and dugongs are in a different large group called Afrotheria.

This shows how science changes and improves as we learn more about the natural world!