Cheliceramorpha includes arachnids, horseshoe crabs and numerous other animals which have become extinct ever since the Paleozoic era. It is the second most prominent class in arthropoda, uniramians being the most. Chelicerates may be predators, parasites, or decomposers. Most chelicerates do not care for their young, instead producing large numbers of offspring, increasing the probability that some will survive, but others, like scorpions, do care for their young.