What is Kimberella?
Kimberella is a highly unusual and important fossil from the Late Ediacaran, dated to between 555 and 558 million years ago, 13 million years before the start of the Cambrian period. Kimberella, originally classified as a jellyfish and then a box jellyfish, had its classification modified in 1997 to that of a stem group mollusk or mollusk-like creature. This was due to anatomical features (such as a dorsal non-mineralized shell) and the presence of scratchings nearby that suggest the animal had a radula, the chitinous tongue universal to all mollusks. Because of the age and classification of Kimberella, it is the oldest well-documented triploblastic (three tissue layered) bilaterian (bilaterally symmetrical) animal in the fossil record. Another, earlier possible bilateran is Vernanimacula, dated to 580-600 million years ago, but some scientists argue that these 0.1 mm objects are just infilled bubbles, not fossils with organic origin. In any case, it shows that the earliest known bilat
