Fossils in Percé

Hi, apprentice scientists!

One of our member asked me a very interesting question! Dominic wants to know: are there any other fossils, apart from the trilobites, in Percé? Indeed, there are many! Many of these fossils are found in geological formations formed of limestone.
But why limestone?
” In the majority of cases, limestones are formed in part by the accumulation of calcareous shells and skeletons. For example, limestone is a sedimentary rock containing at least 50 % Calcite (caco3), but some of these rocks are formed by chemical or biochemical precipitation. (Foucault, A. et Raoult, J.-F., 2010. Dictionnaire de Géologie (7e édition). France : DUNOD, pages : 380.).

Here is a summary description of some fossils found in our beautiful region. I found a large amount of this information in a very interesting document: Small Treaty of urban paléontologie: fossils in the architectural stones of the city of Quebec.

To learn more about the morphology of these fossils, I invite you to consult this document from the ministry of energy and natural resources of Quebec. It will also make you discover how fossils can fit into human constructions ?
Source : Ministère de l’Énergie et des Ressources Naturelles, 2017. Petit traité de la paléontologie urbaine : fossiles dans les pierres architecturales de la ville de Québec. Found at http://gq.mines.gouv.qc.ca/documents/examine/GT201701/GT201701.pdf


1- It is my pleasure to introduce you to the beautiful crinoïdes! Our dear agathe loves them particularly. The oldest fossils recovered were about 480 million years ago, or at the time of the ordovicien (I put a geological calendar down to help you find yourself in all these millions of years)

So far, scientists have identified over 5000 fossil species of crinoïdes. Complete fossils are rare. In the picture below, small columns are stalks whose centre may have different shapes, depending on species. The Crinoïdes are still present today, we call them sea lilies. Beautiful !

 

2- Bivalves are molluscs that appeared about 450 million years ago, but they still exist today and I bet you already ate them for lunch! Indeed, mussels, oysters and clams are Bivalves! Very varied, the habitat of bivalves can go from the coastline to depths of 5 meters!

 

3-Gasteropodes are saltwater and freshwater molluscs, depending on the genera and species. They appeared at cambrian, more than 500 million years ago! They also live today. In fact, it is one of the best-represented groups of invertebrates on earth, both by its diversity and its abundance.

 

4- Brachiopodes are known as invertebrates filters. Since 550 million years, they have diversified into more than 7000 known fossil species. Today, there are only 260 species of brachiopodes.

 


In Conclusion: you have probably noticed that unlike trilobites, these types of fossils (or taxonomic groups) are still present today. The planet has undergone several upheavals since the emergence of life on earth. Some form of life has managed to survive and adapt better than others to these changes. That is why human beings must remain attentive to the changes that our planet is currently experiencing!

Isabelle


I took photographs of these fossil specimens in the display of the accueil reception. Thanks to the generous contribution of Chandler’s mineralogy and paleontology club.

Calendrier des temps géologiques :

Source : http://terre-des-hommes.forumactif.com

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