Dermochelyidae

Dermochelyidae is a family of sea turtles. There is only one living species today: the leatherback sea turtle. It lives in oceans all around the world.

The leatherback sea turtle is the largest turtle. It has a soft shell covered with oily skin, not hard plates. This helps it dive deep into the ocean. These turtles can travel thousands of miles to find food.

Scientists found very old fossils from the Late Cretaceous period. These fossils show how these turtles changed and survived for millions of years.

Classification of known genera

The Dermochelyidae family has several groups of ancient sea turtles. Most of these groups no longer exist, but one group is still alive today.

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 keep learning more about these ancient sea turtles and their family tree.

Phylogeny

Scientists studied sea turtles in 2019. They found that the leatherback sea turtle is the only living member of its family today. The oldest fossils of these turtles are from a time long ago called the Late Cretaceous.