Let me introduce myself … my name is Monique Welten; I studied biology at Leiden University and obtained my PhD at Leiden University in 2007. After my graduation, I worked at several universities in the UK and the USA. My research focuses on evolution and development of the skeleton, teeth, and limbs. Sharks and rays always played an important role in my research, because of their skeleton that consists of cartilage, and their own evolutionary history. Because of this, I developed a real passion for sharks and rays. Right now, it seems a good idea to share my knowledge with a wider public, and the Dutch Shark Society offers me a great opportunity to do so.
Following the activities of Dutch Shark Society during the Fossils Day at Futureland, last 27 January, I felt inspired to write something about fossil sharks and rays in the Netherlands.
Because many fossil shark teeth (and vertebrae, skin plates …) can be found in various places in the Netherlands! That is not surprising, because during the Tertiary era (between 65,5 and about 1,8 million years ago), the largest part of the Netherlands was covered by sea.
The Tertiary period itself is divided into different periods, each with its own typical circumstances such as climate. The website of ‘Geology of the Netherlands’ has good information and beautiful illustrations of the geological time scale:
http://www.geologievannederland.nl/tijd/reconstructies-tijdvakken
Fossil shark teeth / fossiele haaientanden
One of the most popular places to find fossil shark teeth (and many other fossils) is the beach around Cadzand, in Zeeuws Vlaanderen. In the North Sea, the sediments from the different geological eras are turned over, and shark teeth .
Not only small shark teeth in all shapes and sizes can be found, but also the enormous teeth of the super shark Megalodon (Megaselachus megalodon, also known as Carcharocles or Carcharodon megalodon) can be found on the beach. Regularly, sand suppletion takes place; sometimes this new layer of sand is rich in fossils, but sometimes it is not. This, and the fact that people have been browsing the sand for years, can make it harder to find shark teeth. But it’s still extremely exciting to find a tooth, skin plate or spine of a fish that lived so many millions of years ago.
A megalodon tooth – picture: Wiki Commons, user Lonfat
Other locations of teeth of fossil sharks and rays in the Netherlands are near the village of Langenboom (recreational lake De Kuilen). These fossils are also derived from deposits in different periods of the Tertiary. Here, the fossils are in underground sediments, and they come to the surface through the extraction of sand and gravel.
For those who want to read further, here are some links to interesting websites:
https://en.wikipedia.org/wiki/Megalodon
https://www.youtube.com/watch?v=6mjFqjccwFo
https://ukfossils.co.uk/2012/08/01/the-basics-of-classification-2/
https://ukfossils.co.uk/?s=tertiary
https://ukfossils.co.uk/2016/06/16/abbey-wood/
https://ukfossils.co.uk/2007/06/07/walton-on-the-naze/
https://ukfossils.co.uk/2012/01/23/wrabness/
The following are links to information and fossil hunting locations in the Netherlands:
http://www.geologievannederland.nl/tijd/reconstructies-tijdvakken
http://www.geologievannederland.nl/fossielen/vissen/megalodon
http://www.geologievannederland.nl/fossielen/vindplaatsen/langenboom
https://cadzand.org/nl/haaientanden.php
https://nl.wikipedia.org/wiki/Megalodon
