Fossils

Alberta is one of the most diverse places in the world when it comes to seeing evidence of past life. You can hike to the top of many of the local peaks and see fossils of animals that lived over 350 million years ago. You can also head to Dinosaur Provincial Park and see the more recent remains of large dinosaurs (around 70 million years old) like the Albertosaurus (a large meat eater similar to Tyrannosaurus rex). Fossils have been instrumental in allowing scientists to determine the history of life on Earth.

Way back, when fossils were first found far from the nearest sea, it was seen as support for the idea of a universal flood. Early philosophers like Pythagoras and Aristotle suspected that they were the remains of long dead animals and plants but later, during the dark ages, they were considered to be freaks of nature. They believed fossils to be rocks that merely had an accidental resemblance to animals or plants. Their origin could be easily explained with magic. It wasn't until the Renaissance that men like Leonardo da Vinci and Bernard Palissy began to again follow the beliefs of the early philosophers.

This meant that if fossil shells were found far from the nearest ocean than at one time there had been an ocean at that particular location. Today fossils are studied the world over. In Alberta, the Tyrrell Museum provides one of the best facilities in the world for the study of fossils.

Fossils can take a number of different forms. Generally in the mountains, shells and other fragments were covered by silt and other materials and eventually decomposed. However as they decayed, a few left behind an impression or mould of itself. The original shell slowly disappeared completely and the mould was all that remained. In the case of shells, the inside of the shells sometimes also filled with material and formed a mould of the inside of the shell as well.

The shape of the original object can be recorded with incredible accuracy. and on occasion these moulds are filled with other materials that eventually harden into rock--similar to filling the mould with plaster of Paris. This leaves a perfect cast of the original shell and provides an almost exact replica. The material forming the cast can be lime, silica, clay, sand or any of a series of other materials.

This is only one of a variety of methods that have preserved the world's early plants and animals. In most areas of the world the most common type of fossils are the remains of the hard parts of an animal, like the bones or teeth. Amber is prehistoric tree resin which has hardened and often contains perfectly preserved insects and spiders. Petrified wood was formed as the wood material was slowly replaced by minerals percolating though it as it decayed.

Fossils shells and corals are not uncommon around the Bow corridor. As you hike the local trails, take the time to look closely at the rock faces as you pass them and before long you will begin to spot some of the early residents of this area.