Eldredgeops rana can be recognized by its large
eyes (which remind some observers of a
frog's eyes—the specific name
rana is a reference to a common frog), its fairly large size (up to 6 inches long), and its habit of rolling up into a ball like a
pill bug ("
volvation"). In order to protect themselves from
predators,
Eldredgeops rana would roll into a ball with its hard
exoskeleton on the outside as protection. Many other trilobites possessed the same ability, but
Eldredgeops rana nearly perfected it. The slightest amount of
sediment would trigger their senses, and
Eldredgeops rana would be hidden in a tiny shelter made of its own body. Although this safety feature often helped them to evade predators, occasionally it backfired and the trilobite would be buried under heavy sediment. Their
fossils can still be found in balled-up positions 400 million years later. == Fossilisation ==