Mammals first appeared 225 million years ago and, for a long time, they coexisted with the dinosaurs. There are currently 5,500 species across all the continents. The Muséum has one of the oldest mammal collections in the world.

The mammal collection comprises over 130,000 specimens, including over 1,500 types. It consists of stuffed specimens, skeletons and skulls mounted on stands, and animals preserved in fluid. It is organised into several subcollections, such as comparative anatomy and zoology (comprising mammals and birds). These subcollections are now located near to the research teams, in the large specimen storeroom, in the Zoothèque, the Grande Galerie de l’Évolution, the Galerie d’Anatomie comparée, or in the off-site storage facility. Collections of anatomical parts in fluid, tissue samples in alcohol, bones from regurgitated pellets and cryopreserved cells are also available for molecular analyses and anatomical studies. The mammal collection is currently being computerised.

The oldest object, which can be seen in the Galerie d’Anatomie comparée, is a bone that, in the time of Louis XIII, was thought to belong to a giant. In 1762, Daubenton demonstrated that it actually came from a giraffe, using comparative anatomy without ever having seen this animal. The oldest specimens date back to the mid-18th century. There are around twenty mammal specimens left from Buffon’s time, including Jocko, his tame chimpanzee. The collections brought back by the great French expeditions in the first half of the 19th century, like those of the "Naturaliste" and the "Géographe" (Captain N. Baudin), "L’Uranie" (L. de Freycinet,), "La Coquille" (I. Duperrey), or "L’Astrolabe" (J. Dumont d’Urville) are among the most important contributions. The same goes for the specimens collected by M. Lamotte, F. Petter and G. Dubost in the 20th century. This collection is still growing, with hundreds and thousands of specimens being added every year, in particular due to the activities of the Muséum’s scientists.

These collections have primarily scientific, educational and museographic purposes. The mounted mammals and skeletons are displayed to the public at exhibitions. On a scientific level, the collections are used in particular in systematics, biogeography, ecology, archaeology, palaeontology, functional morphology and comparative anatomy. The tissue samples and specimens are a source of DNA for phylogenetic and genetic studies. These collections are made available to researchers all over the world, by visit or loan, and are mentioned in many scientific publications. In recent years, the main conservation activities of the national collection have involved computerisation, incorporation of new specimens, visitor reception, loan management, expertise as part of the fight against the trade in protected species, and coordination with international databases.