The SMP has large collections of Pennsylvanian plant fossils (many from the St. Clair, PA area), Devonian brachiopods and trilobites from throughout PA, and Late Cretaceous vertebrates from New Mexico.
Recent donations to the SMP include impressive collections of Devonian trilobites from northcentral Pennsylvania; Cretaceous eggs, many from dinosaurs; fossil feathers, mainly from the Eocene period; fossil fishes from the Triassic; and Mesozoic insects. Donations are an important part of any museums collection, and these recent donations have added tremendous scientific value to the SMP's fossil collections.
The SMP possesses several type specimens, some of which are from Pennsylvania and several are from the Cretaceous of New Mexico, including several dinosaurs.
The SMP is the official repository of fossil and geologic specimens for the state of Pennsylvania. This means that fossil specimens collected in Pennsylvania, particularly by the Pennsylvania Geological Survey, go to the SMP unless they are private or collected through a permit. Additionally, historic geologic collections also are held by the SMP, including those collected through the official geologic surveys, dating back to the early to mid 1800's.
The Section of Paleontology and Geology at the State Museum of Pennsylvania (SMP) possesses fossil vertebrates, fossil invertebrates, and fossil plants, along with mineral and geologic specimens. As of 2020, the collections include approximately 6,500 fossil vertebrates, 15,500 fossil invertebrates, 9,000 fossil plants, and approximately 7,500 mineral and geologic specimens. The majority of which come from Pennsylvania.
In addition to the type specimens, the SMP has several other impressive and important specimens. These include the most complete mastodon and mammoth specimens known from Pennsylvania. The Marshall's Creek Mastodon, collected in Monroe County, PA in the 1960's, is on display at the SMP. The Moon Mammoth was collected by George Moon from a kettle lake in Erie County, PA, although it is unfortunately not yet on display.