What are Some Silurian Organisms?
Silurian organisms lived during the Silurian period, which lasted between 443.7 and 416 million years ago. The Silurian is the shortest geologic period aside from the Neogene, with a total length of just 27.7 million years. In contrast, the Cretaceous period lasted 80 million years. The Silurian period occurred immediately after the Ordovician and just prior to the Devonian. The beginning of the Silurian is defined by a series of extinction events, so severe that they wiped out 60% of all animals, the second largest mass extinction in history. The most famous organisms of the Silurian are the numerous fishes that evolved during this time, some of which had distinctive shielded heads (placoderms and relatives), the eurypterids (sea scorpions), marine predators which extended up to 2 m (6.5 ft) in length, and the earliest well-developed terrestrial flora and fauna, including vascular plants and terrestrial arthropods such as millipedes, mites, harvestmen, springtails, and spiders. The Si
