The geological collection of Naturalis consists of 3,200,000 fossils and 800,000 rocks & minerals. The collection has samples from all over the world, though the larger part of the collection originates from Europe. A substantial part however, has been collected in Indonesia.
The 19th century Dubois Collection is worldfamous and, consists of more than 40,000 fossils from Pleistocene vertebrates of Indonesia. The crown jewels are the femur, molar and skull-cap of Homo erectus, which are on display in the museum. Another important collection from Indonesia is the Martin Collection, which consists of fossil shells from the Cenozoic of Java. This collection contains almost 2000 type lots, which are the basis for the scientific names of many molluscs from the Indo-Pacific.
Naturalis houses many Pleistocene vertebrates from the Netherlands and the surrounding area (North Sea), including the largest collection of woolly mammoth bones in the world. Other species represented are woolly rhino, bisons, giant deer, cave hyena and cave lion, all dating to about 50.000 years BP. Older periods are represented by the Tegelen (Tiglian) collection covering over 5000 dental Late Pliocene elements of small mammals and numerous remains of reptiles and amphibians. The Miste Collection from the famous locality 'Miste' near Winterswijk, the Netherlands, is evidence of a subtropical fauna during the Middle Miocene of the North Sea Basin area with over 500 species of molluscs. Other molluscs have been collected from the Dutch beaches and estuaries, with over 600 species currently present in the collection.
One of the most significant collections from other parts of Europe is the Gargano collection of Neogene mammals. It has in it some remarkable species such as the giant hedgehog Deinogalerix and the five-horned artiodactyle Hoplitomeryx. It is the largest in the world, with tens of thousands of fossils.
From the UK there is the Reid & Reid collection of fossil seeds, which marks the boundary between the Tertiary and Quaternary.
A special category is formed by the collections of unbalanced endemic island faunas of vertebrate fossils from Flores, Sulawesi, Cyprus, Majorca and Crete, including strange island forms like giant rats and pygmy elephants.