Artist’s depiction of Silurian animals, including, from left: bryozoans, crinoids, clams, cephalopod, jelly, sea scorpion (Pterygotus), brachiopod, jawless fish (Birkenia), gastropod shell, brittle star, trilobite, bivalve mollusk, sponges, sea star. It lived in the Late Jurassic period around 150 mya, in what is now southern Germany during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now. * The Silurian was named by Murchison in 1839 for the Silures, a tribe of the Welch borderland. nsabolsky. Note that complete ones are 6-rayed. Event experiences. During the Silurian period Earth's continents joined together, closing the Iapetus Ocean and forming two supercontinents: Laurasia in the north, and Gondwanaland to the south. ; Jane went home at lunchtime. cystoid on the upper right, (ToL: Mollusca