The Naturhistorische Museum Landessammlung für Naturkunde Rheinland-Pfalz (nhm) in Mainz preserves and presents the state's natural science collections. It combines biological and geoscientific research with public outreach and also displays exhibits from its partner country Rwanda.
Part of the exhibition space is located in the former Clarissan church of St. Klara, whose building history dates back to the 13th century. The monastery acquired extensive lands and privileges in the Middle Ages, changed its ownership arrangements several times and was secularized in the late 18th century; plans to convert it into a hospital remained unfinished. In the centuries that followed, the buildings served, among other uses, as emergency accommodation, a military facility, storage, and—during the occupation—at times as a bakery or supply office.
The museum collection originated in 1834 with the founding of the Rheinische Naturforschende Gesellschaft. The church of the former monastery was altered in the 19th century and from 1910 served as the museum building. Significant fossil finds in the 1920s from Nierstein (Permian, track-bearing slabs, approx. 290 million years) and from Wallertheim (Ice Age hunter's camp) contributed to the institution's reputation. Much of the collection was lost when the church was destroyed by bombing in February 1945. The collections were rebuilt after the war and the museum reopened in 1962. Following renovation work that began in 2007 and a subsequent conversion, the museum reopened at the end of September 2019.
The exhibition displays, among other items, Permian trackways from Nierstein as well as more than 25,000 finds from the Mosbach sands near Mainz-Amöneburg, including Ice Age animals such as hippopotamus, steppe mammoth, elk, wolf, Mosbacher lion, Panthera gombaszoegensis and saber-toothed cat (from about 500,000 years ago). A historical milestone was the 1988 founding of the Landessammlung für Naturkunde Rheinland-Pfalz for the systematic documentation of biological and geoscientific reference collections. Showrooms include rare quagga specimens, horse finds from the Eocene to the present, an extensive mineral collection related to the mineral resources of Rhineland-Palatinate, and a focus on the native birdlife.
Since November 2024, some exhibits from the Gutenberg-Museum have been temporarily displayed in the museum's left wing under the title “Gutenberg-Museum MOVED.” In the Typmineral-Katalog Deutschland the museum is listed as the repository for the type minerals Belendorffit (HT, M 2004/57-LS) and Strengit (HT, M 1989/709); the IMA's type mineral catalog additionally records Hentschelit (CT) as a deposited type mineral.