Tasbacka is an extinct genus of sea turtle containing several species.

[1][3] Though the type species, T. aldabergeni, has only been found in Kazakhstan,[4] Tasbacka had a wide distribution.

[2] In 2008, researchers found a well-preserved, juvenile specimen of T. danica in Denmark's Fur Formation.

Modern sea turtle hatchlings also have dark shells; while a hatchling floats on the ocean's surface, its dark coloring enables it to absorb heat from the sun and avoid predatory birds.

The existence of similar pigment on an ancient specimen suggests sea turtles evolved this survival trait millions of years ago.