Permian period was a geological period which started 300 million years ago and that finished 250 million years ago. In Permian period there were important climatic changes like an inclination to tropical climates and more dry conditions. Marshes began to dry and the amphibians and plants which live there became extinguished. As a result, reptiles, mammal reptiles and the plants with seeds occupied the earth. The Permian period ended with the largest mass extinction in Earth's history, in which nearly 90% of marine species and 70% of terrestrial species died out.
Conifers developed strongly during Permian period. This plant is a relative of the Araucaria, which can often be seen in gardens nowadays. The conifers had their first appearance in the Late Carboniferous, but they became common, and sometimes even dominant, in the Early Permian. The ferns continued their evolution like they do until now.
The Chondrichthyes are a kind of aquatic vertebrates known as cartilaginous fishes. This is due to the fact that they skeleton is made of cartilage. They lived during the Permian period. This class is formed principally by sharks, but also by rays and chimeras. Their basic structure and many of their natural characteristics are the same from the beginning. For example, the fact that they are one of the most important predators of the sea. However, after some time they developed several characteristics like a growth of size to avoid being a prey or a development in the teeth. On the one hand, sharks had a length around 1,5m, they only had scales around their eyes and their two fins and they had problems to chew the animals. On the other hand, they were very fast fishes.
Walchia is a fossil of conifer, cypress-like genus. It is found in Europe and also North America. One of the most common locations of walchias is the forest located on Northumberland Strait coast at Brule, Nova Scotia where, apart from this kind of trees, many tracks of an insect called monuran can be found.