04Paleozoic
Trilobites
Trilobita
They occupied seafloors for nearly 300 million years, and their compound eyes preserve secrets of early vision.
EXTINCT ATLAS WIKIEXTINCT LIFE ARCHIVEBack to archivePeriod · 443.1–419.62 million years ago
Silurian Animals, Plants & Fossils
Explore sea scorpions, early jawed fishes and small land plants in the Silurian fossil record.
Life and the fossil record
Ecosystems recovered after the end-Ordovician extinction. Reefs and fishes diversified while plants developed more complex structures on land. This did not instantly produce forests: small branching plants and aquatic arthropods show distinct stages in the development of coastal and terrestrial ecosystems.
101Paleozoic
Eurypterus
Eurypterus remipes
Paddle-shaped hind limbs carried this sea scorpion through shallow coastal water.
121Paleozoic
Cooksonia
Cooksonia pertoni
Leafless stems only centimeters tall held spore capsules at their tips, marking an early step inland.
210Paleozoic
Pterygotus
Pterygotus anglicus
Flattened swimming paddles and great toothed claws made it a formidable hunter in Silurian water.
256Paleozoic
Acutiramus
Acutiramus cummingsi
Its long pincers carried slanting blades suited to holding or slicing soft prey.
257Paleozoic
Climatius
Climatius reticulatus
Rows of paired ventral spines formed a defensive fence beneath this small early jawed fish.
306Paleozoic
Tortotubus
Tortotubus protuberans
Branching microscopic hyphae show fungi helping to build the earliest soils.
310Paleozoic
Chain coral
Halysites catenularius
Linked tubes formed honeycomb chains across Paleozoic reefs.
311Paleozoic
Atrypa
Atrypa reticularis
Fine radial ribs covered rounded shells that once crowded ancient seabeds.
399Paleozoic
Prototaxites
Prototaxites dawsonii
Meter-high columns towered over landscapes of otherwise low vegetation.
415Paleozoic
Receptaculites
Receptaculites oweni
Spiraled diamond plates formed a calcified pinecone-like body.
416Paleozoic
Cyclocrinites
Cyclocrinites dactioloides
Whorled calcified branches surrounded a central axis like an underwater bottlebrush.
437Paleozoic
Entelognathus
Entelognathus primordialis
Placoderm armor enclosed jaw-margin bones resembling those of later bony fish.
554Paleozoic
Nematothallus
Nematothallus
Carbonized cell sheets and tangled tubes came from an enigmatic early terrestrial organism.