As construction for our expansion progressed, the Devonian Reef diorama had to be moved to accommodate the opening to the new Learning Lounge. We took this opportunity to redevelop our Palaeozoic Era exhibit to showcase a greater diversity of animal life including new specimens from the Ordovician, Silurian, Devonian, Carboniferous, and Permian periods.
Since the majority of rocks exposed in Alberta are from the Cretaceous Period, there is a small amount of Palaeozoic Era fossils in the province. This exhibit contains original fossils and casts from Alberta, other provinces, and countries to display the incredible diversity of animal life 514 – 252 million years ago.
The Legacy of the Cambrian Period 541 – 485 million years ago
Over 95 percent of all animal species are invertebrates—animals without backbones. Invertebrates originated in marine waters (oceans and seas) and diversified greatly during the Palaeozoic Era. The fossils of the Burgess Shale in British Columbia, and other Cambrian fossil sites around the world, document the origin and diversification of virtually all major groups of animals.
Ordovician Period 485 – 444 million years ago
The climate was warm during much of the Ordovician Period. Oceans covered large portions of the globe, including across much of North America. During the last part of the period, sea levels dropped and the climate cooled as massive glaciers formed in the Southern Hemisphere. The first vertebrates (animals with backbones) appeared in the form of jawless fish.
Silurian Period 444 – 419 million years ago
Sea levels rose during the Silurian and the climate became more stable and warmer. Many groups of marine animals recovered from the end-Ordovician extinction, including crinoids and sea scorpions. The first corals and several groups of fishes with jaws appeared. Some fishes also began living in freshwater environments, like rivers and lakes.
Devonian Period 419 – 359 million years ago
Known as the “Age of Fishes”, the Devonian Period was the time when fish groups exploded in diversity. A variety of jawless fishes and five major groups of jawed fishes co-existed in the Devonian waters. During the Late Devonian, tetrapods (four-legged animals) started to evolve from lobe-finned fishes. Canada has two of the world’s most important Devonian fish localities, located in the Northwest Territories and southeastern Quebec.
Carboniferous Period 359 – 299 million years ago
Following the extinctions at the end of the Devonian Period, marine communities recovered and adapted to changing sea levels and global temperature changes in the Carboniferous Period. Sharks, their relatives, and several groups of bony fishes soon dominated the waters. Shallow seas covered and then retreated over the landmasses. Vast coal swamps covered large areas of land, leading to the creation of thick coal seams in eastern North America and Western Europe.
Permian Period 299 – 252 million years ago
Variable temperatures and overall dry conditions occurred during the Permian Period. Previously isolated continents—Euramerica and Gondwana—joined to form Pangaea, a single super continent. This gigantic land mass reduced the amount of coastline and shallow, offshore environments where marine organisms lived. The world’s most catastrophic mass extinction took place at the end of the Permian Period, devastating marine communities.
Illustrations by Léonard Dupond. Commissioned by the Royal Tyrrell Museum of Palaeontology.