The Paleozoic Era

The Paleozoic Era

538.8Ma-251.9Ma

+ info

• The world during the Paleozoic Era covered a series of geological events on Earth. Oceans basins such as the Iapetus and Rheic Oceans formed and sustained sea-level transgression occurred. During this period a large amount of CO2 was released into the atmosphere, resulting in one of the Paleozoic's warmest intervals. However, during the Late Silurian period, the Lapetus Ocean closed.
• During the Late Paleozoic Era continental collisions occurred, which resulted in the formation of the massive supercontinent Pangaea. The Pangaea created great mountain chains such as the Appalachians, Ural mountains, and mountains of Tasmania.
• The beginning of the Permian took place during the “Late Paleozoic Ice Age,” followed up by the climatic transition from an icehouse to a greenhouse. Towards the end of the Permian, Equatorial and high-latitude surface temperatures increased substantially. This resulted in the largest bio-crises in Earth’s history, causing 95% of marine and 70% of terrestrial life to disappear on Earth.
• During the Early Carboniferous global temperatures dropped dramatically, which caused the Earth’s climate system to enter the icehouse condition. During the Early Carboniferous period Amniotes appeared, including animals that laid eggs, reptiles and birds, and placental animals. It was during this time period that living reptiles and all other living terrestrial vertebrates also appeared. Reptiles began as cotylosaurs and stem reptiles and diverged into two different lineages-the synapsids and sauropsids (or diapsids). Periodic eggs appeared, which had a leathery or calcareous shell that allowed animals to roam far from water without having to return to water to lay eggs. Towards the end of the Carboniferous, the climate in equatorial Pangea became more seasonal and arid.
• During the early Permian, beetles appeared and marine and terrestrial life flourished. This included conodonts, trilobites, ammonities, protomammals, sea scorpions, and brachiopods. Pelycosaurs and their descendants would go on to dominate during this time. The diapsids evolved into turtles, lizards, crocodiles, and eventually birds.
• During the Ordovician Period, invertebrate life became increasingly diverse and complex, with both calcareous and siliceous sponges becoming known, along with the first stromatoporoids appearing. Other species that appeared during this period include the tabulata, rugosa corals, bryozoans, brachiopods, and mollusks. During this period, Echinoderms reached their peak diversity of 20 classes. Life diversified substantially, which caused a fourfold increase in the number of genera.

Major Events Occured

• One major event that occurred during this time period included the Cambrian explosion which caused a major diversification of marine animals. This intense diversification resulted in more than 35 new animal phyla.
• The other major event that occurred included the End-Permian extinction, the greatest mass extinction in Earth’s history. This extinction eliminated major invertebrate groups including the blastoids, fusulinids, and trilobites. It is estimated that 95% of marine invertebrate species perished. Although it's unclear what caused the extinction, it is believed to have happened by changing climate and exceptionally low sea levels.

Fun facts:

• During the year 1835, British geologist Adam Sedgwick discovered the base of the Paleozoic Era as the first occurrence of complicated life via rock records.
• Many ancestors of modern animals originated from the Cambrian explosion.
• During the Carboniferous Period, terrestrial plant life peaked, and lycopsid rainforests dominated the tropical region of Euramerica.
• Ampimiands were the most common tetrapods until the Mid-Carboniferous Era with the occurrence of climate change causing a decrease in their variety.
• During the Paleozoic Era, sea levels reached 200 meters above current levels.
• The initial appearance of conodont Hindeodus Parvus identified the transition between the Paleozoic and Mesozoic eras.

Use tables and infographics

Visual communication is a key tool. It is easier for us to 'read' images than to read written text. Therefore, disciplines like Visual Thinking facilitate knowledge organization through the use of images, graphs, infographics, and simple drawings.