Starfish first appeared in the fossil record in the Cambrian. The first known asterozoans were the Somasteroidea, which exhibit characteristics of both groups. Starfish are infrequently found as fossils, possibly because their hard skeletal components separate as the animal decays. Despite this, there are a few places where accumulations of complete skeletal structures occur, fossilized in place in Lagerstätten — so-called "starfish beds". By the late Paleozoic, the crinoids and blastoids were the predominant echinoderms, and some limestones from this period are made almost entirely from fragments from these groups. In the two major extinction events that occurred during the late
Kina (animal) can be entirely eaten away, leaving bare rocks, also known as Kina Barrens. Larval stages can feed on different species of unicellular algae in a size range between 5 and 50 µm (MacEdward and Miner 2007). Molluscs such as the cymatiid gastropods "Charonia capax" and "C. rudicunda", starfish, and benthic feeding fishes can feed on individuals of "E. chloroticus" (Dix 1970a). The most important predators are the eleven-armed sea star, "Coscinasterias calamaria", the seven-armed prickly starfish, "Astrostole scabra", and the spiny lobster, "Jasus edwardsii" (Andrew and MacDiarmid 1991, Barker 2007). "Evechinus chloroticus" has an annual breeding cycle (Dix 1970b). It