The creature possessed six abdominal segments rather than the eleven of true insects, no wings, and an appendage poking down from the first segment that seemingly held the creature fast to a surface. Their ability to adhere to the underside of a leaf may have its merits, but the sticky extra limb, called a ventral tube, is also used for drinking and breathing. Scientists are still determining whether the tube is also used for excretion. Back in the 1800s, scientists naturally classified the newly found creature in the phylum Arthropoda, a huge group of creatures with external skeletons and jointed bodies, that encompasses three-fourths of all known animals. Deciding exactly where to place Collembola within a group that includes butterflies, prawns, and spiders gets tough.
Some scientists think they resemble crustaceans more closely.
Or perhaps they deserve their own class entirely, as most believe, in appreciation of certain differences in anatomy and genetics. Christiansen thinks of himself as a lumper but says he hasn't got time to quibble. End of discussion. Since the day Collembola were first discovered, thousands of species displaying attractive hues have been found living in almost every strata of society. You get the general idea.