A special type of dredger used for mining sand in the Groote Wielen area of Den Bosch enabled amateur paleontologists Anton Verhagen and Dick Mol not only to add to their collection of bones, but also to keep track of the corresponding geological eras. The sand harvested by cutter-suction dredger Den Otter was to be used for building a new, nearby neighbourhood, and had to be scraped layer by layer in order to separate high-grade building sand from the rest. This method of dredging is slower, but because it separates out different types of sand early on, it’s apparently still cost-effective.
Besides bringing up sand neatly separated by geological period, the cutter-suction method has the added advantage of leaving smaller bones intact, reports De Telegraaf (Dutch). Since 2005, Verhagen and Mol found over 1,000 bones belonging to 15 separate mammals in this dig. Among them was the thigh bone of a mammoth.
Next Wednesday, Verhagen and Mol will be publishing a book called ‘De Groote Wielen: er was eens…’ (Once upon a time in De Groote Wielen) about their finds. A preview of the richly illustrated book can be found here.