What Was the Earth Like?
We’ve examined some ofthe creatures that existed before the dinosaurs, but what was the Earth likeway back then?
From 354 to 290 millionyears ago was the Carboniferous Period. Hot and humid conditions covered thenorthern landmass, while the southern lands were much colder. Large clubmosses, tree ferns, and horsetails grew in swamps and estuaries, along withseed-bearing plants. Some plants were up to 100 feet tall.
The insect populationwas quite varied, with millipedes, dragonflies, and other bugs. Some flyinginsects had wingspans up to two feet wide! Around the middle of the period,reptiles evolved as the first land-dwelling animals, and sharks and bony fishesreplaced the jawless agnathans and armored placodems in the seas. Starfish,gastropods, sea urchins, and other marine invertebrates flourished on thereefs.
Approximately 350million years ago, coal forests began to form in wetlands at the edges ofcontinents. The submerged plant matter did not decompose completely and endedup being buried. This eventually transformed into coal.
The early reptiles hadsimilar skeletal features to those of amphibians, but there were differences intheir skulls and vertebrae that signified their relationship to later reptilessuch as turtles and dinosaurs.
Then came glaciations,a decrease in sea levels, and the formation of Pangaea, when the continentsjoined together. A minor extinction event of both marine and land life happenedat the end of the period due to climate change. This is known as theCarboniferous rainforest collapse.
