The Silurian was a period in Earth's history. During the Silurian, the land was covered in deserts, inhabited only by huge insects, some of which were deadly. The atmosphere was high in carbon dioxide but had low levels of oxygen, due to which lifeforms from more modern time periods would be unable to survive in a Silurian environment for more than a matter of weeks at the most. Some areas of land in the Silurian were also volcanic, riddled with hidden sinkholes and plagued by seismic activity.
Visits and incursions
Sprat ultimately escaped back through the Anomaly to the present, while Taylor was forced onto a crop of rocks to escape from giant scorpions. A mercenary known as the Cleaner and two other mercenaries, working for Oliver Leek, travelled through the Anomaly into the Silurian in search of creatures to capture for Leek's creature army, but they were attacked by a scorpion leaving the Cleaner the only survivor. The Anomaly Research Centre team sent a probe through the Anomaly for research and noticed Taylor trapped. Nick Cutter and Stephen Hart travelled to the desert through the Anomaly to rescue Taylor, but the three were marooned there when the Anomaly closed before they could return through.
Just before the Anomaly closed, one Silurian Millipede travelled through to the present, but was quickly sent back through by Abby Maitland. Another Anomaly to the present eventually opened up in the Silurian, and Cutter, Taylor and Stephen travelled across the desert to reach it. After hiding in some caves from a sand storm, the Cleaner tried to take their water, Anomaly detector and leave them stranded, but he was killed by a Scorpion. Later, Taylor fell over on the sand, causing a scorpion to drag Stephen under the surface, but she quickly distracted it by jumping on the sand, bringing the arachnid back to the surface. The trio then narrowly escaped by sliding down a sand dune on a scorpion's shell, and they all ran through to the present via the Anomaly.
Leek obtained three Silurian Scorpions which he kept in his Creature Prison. One was planted at a beach, where it killed two people before Stephen harpooned it to a pier and left it to be captured by the ARC. The other two Scorpions were presumably killed when the creatures were locked in the Creature Prison's cage room and destroyed each other.
An Anomaly to a Spaghetti Junction opened in a desert in the Silurian, and a Brontoscorpio travelled through between the Silurian, the Spaghetti Junction and 2012. Evan Cross and Dylan Weir came through the Anomaly into the Silurian, where Dylan became trapped in a sinkhole and was attacked by the Brontoscorpio, before it retreated back to its burrow when a taser was fired into its mouth. Evan and Dylan followed the Brontoscorpio into its burrow and cut its tail off, and Evan was then trapped when seismic activity caused the burrow to cave in. Dylan then reluctantly left Evan and ran back to the Anomaly with the stinger.Project Magnet, then almost immediately returned to rescue Evan. Connor Temple also came through the Anomaly into the Silurian, where he met up with Dylan and together the two made their way back to the Brontoscorpio burrow.
Shortly after Evan knocked the Brontoscorpio out with a taser, Connor and Dylan managed to rescue him from the burrow, and the three then made their way back across the Silurian desert and went back through the Anomaly to the Spaghetti Junction.
The Silurian period lasted from approximately 443 to 419 million years ago. During the Silurian, the climate was stable and cooling down after the Ordovician-Silurian extinction event, and jawed and bony fish were beginning to evolve and become diverse. Though life was still mainly underwater in the Silurian, a few invertebrates and other organisms had begun to take to land in the form of small terrestrial arthropods and basic shore-based plants.