Dermochelyidae

Dermochelyidae is a family of sea turtles that includes one living species and several extinct ones. The only living member of this family is the leatherback sea turtle, which is found in the world’s oceans. These turtles are special because they are different from other sea turtles in their appearance and way of life.

The leatherback sea turtle is the largest turtle in the world. It has a soft, flexible shell covered with oily skin instead of hard plates, which helps it dive deep into the ocean. These turtles can travel thousands of miles across the ocean in search of food.

Scientists have found fossils of Dermochelyidae turtles that are very old, dating back to the Late Cretaceous period, a time long before dinosaurs went extinct. These fossils help us learn about how these turtles have changed and survived over millions of years.

Classification of known genera

The Dermochelyidae family includes several groups of ancient sea turtles. Most of these groups are no longer around today, but one group still exists.

This family has many old groups, or genera, that scientists have found fossils of. Some of these include:

• †Arabemys
• †Eosphargis
• †Gigantochelys
• †Helianthochelys
• †Mesodermochelys

One subgroup, called Dermochelyinae, has two smaller groups inside it:

• Tribe †Uelocini

  • †Cardiochelys
  • †Natemys
  • †Ueloca
  • †Zealosphargis

• Tribe Dermochelyini

  • †Cosmochelys
  • Dermochelys (which includes the living leatherback turtle)
  • †Egyptemys
  • †Psephophorus

Some old sea turtles that were once thought to be part of this family, like †Mesodermochelys from Japan, are now known to belong to a different group. Scientists continue to learn more about these ancient sea turtles and their family tree.

Phylogeny

Evers and other scientists studied the family of sea turtles in 2019. They looked at how these turtles are related to each other and found that the leatherback sea turtle is the only living member of its family today. The oldest fossils of these turtles come from a time long ago called the Late Cretaceous.