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
Spiny turtle Spiny turtle The spiny turtle ("Heosemys spinosa") inhabits lowland and hill rainforest, usually in the vicinity of small streams, mainly in hill areas up to 900 m above sea level. The origin of its common and specific name is immediately apparent from the sharp, pointed, spiky-edged carapace, and spiny keel, of this unique turtle, also known as the ‘cog-wheel turtle'. The spiny turtle is known from Brunei, Indonesia, Malaysia, Myanmar, the Philippines, Singapore, and Thailand. Mating behaviour appears to be triggered by rain; in captivity, spraying males with water results in them chasing females and attempting to mount. Nothing is