Jurassic Museum of Asturias The museum displays and collections cover 3,500 million years, and although they emphasize the three stages of the Mesozoic (Triassic, Jurassic and Cretaceous), information is also presented on the preceding and subsequent periods. Different stages of the Jurassic geologic period and system are on display. Corridors contain over 20 dinosaur replicas; measuring over in height, their weight would exceed ten tons if the replicas were real. A rich collection of footprints and fossils found in the Asturian Jurassic coastline from ten paleontological sites are exhibited in the exposition halls and are said to be "the most complete informative and representative
Sea urchin with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus "Miocidaris", which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper Triassic, their numbers increased again. Cidaroids have changed very little since the Late Triassic, and are the only Paleozoic echinoid group to have survived. The euechinoids diversified into new lineages in the Jurassic and Cretaceous periods, and from them emerged the first irregular echinoids (the Atelostomata) during the early Jurassic. Some echinoids, such as "Micraster" in