The National Museum of Natural History (NMNH) is one of the largest natural history museums in the world, but what might surprise some visitors, is that behind-the-scenes we also have an unsurpassed array of type specimens!
A type specimen is generally understood to be the original specimen from which a description of a new species is made. However, a type specimen is not always a holotype, which is the kind of type specimen that a species is named after. For a summary of the many types of type specimens, whether holotype, syntype, or allotype, see this excellent chart from the Australian Museum. For more information, see the Wikipedia article on biological type.
Oporornis tolmiei tolmiei, Catalog No. A1861, Collected by J.K. Townsend on 4 May 1836. Type status: Cotype. Common Name: MacGillivray's Warbler. Photo Credit: Copyright Smithsonian Institution. http://collections.si.edu/search/results.htm?q=record_ID:nmnhvz_4286923
At NMNH we have type specimens of all kinds, from birds, to insects, mammals, plants, fish, rocks and more. Each biological or botanical specimen would have been collected by a scientist in the field, and brought back to the museum for further study. At this point in the process it would just be a specimen. To become a type specimen, a bird specimen, for example, would have to be studied and found to be a new species that had never been described before. Then by studying and publishing the description of that new bird species, the specimen they studied would become the type against which all future birds of that species would be compared. This process would also include choosing a scientific name for that species. Sometimes scientists pick the names of their teachers or colleagues, while others may pick a humorous name, like the Tamoya ohboya. Other scientists prefer to pick more traditional descriptive names, like Brian Schmidt who named the bird, Stiphrornis pyrrholaemus, which is Greek for "stout bird that bears a flame-colored throat." At NMNH, the Division of Birds alone holds 4000 primary type specimens, while the entire museum has at least 874,878 type specimens.
Here in the Division of Archaeology, we do not have “type specimens” in the biological sense, but we often collect objects of a known type to help other archaeologists and researchers better identify what they find. One such research collection is the Dickson lithic type collection, which consists of rock samples usually found in NW Arkansas, NE Oklahoma, SW Missouri, SW Kansas, and South Central Kansas. Archaeologists will use this collection to help them identify rock types used in the production of Native American stone tools, such as arrowheads. Each rock sample was taken from a known geological layer, and has information about exactly where in the state it was found. This information will help archaeologists find out where a particular stone tool’s source material might have come from, in relation to the place where it was found. Where a stone was sourced from can tell us about trade, and what kind of networks might have existed within or between tribes to get high quality raw materials from farther away. For example if an arrowhead was made out of a rock type only found in Kansas, but the arrowhead was actually found in Arkansas, we might infer that trade was happening between those areas.
The lithic raw materials in the regions mentioned above can be highly variable; a single geological formation may include potentially usable stone that varies in color and texture. Because of this variability, archaeologists working without the benefit of a type collection can easily make an incorrect identification of the lithic source. Don Dickson, who was the collector of this particular lithic type set, has an abiding interest in geology and lithic use in North America and was employed for many years as an archaeologist at the Arkansas Archaeological Survey. Mr. Dickson’s sampling strategy is extremely well documented, and his identifications are superior in their scientific rigor. Specimens were examined under sophisticated microscopes to determine correct dating and stratigraphic level using corroborating evidence from microfossils present in the specimens. The collection contains 130 sets (or lots) of primarily chert, quartzite, quartz, novaculite, rhyolite, felsite, and obsidian, which were the lithic types most commonly used to make stone tools. This lithic type collection goes beyond what a regional geology collection could offer to archaeologists, because it was collected by a geologist specifically for the purpose of identifying stone tools and raw materials found in archaeological assemblages. Without collections like these, it would be extremely difficult for non-geology specialists to reliably identify the source of a stone artifact or core, and how far afield it may have traveled to be found in its archaeological context. For more information on how geology and rocks are classified as lithostratigraphic units, or type localities, read this article on geologic type.
Beyond their usefulness, these samples are also often particularly beautiful to look at, ranging from light pink novaculite speckled with black, to wavy grey Cotter chert, to a specimen of roubidoux that was elegantly encrusted in crystals. Even the heavy, black Precambrian rhyolite has a certain gravitas about it. Enjoy!
-Meghan Mulkerin, Collections Specialist Contractor
Further Resouces, July 2, 2013: Don Dickson's complete collection (of which we have a smaller duplicated type set) was donated to the University of Tulsa. His colleague Jack Holland, who maintained a very strong lithic type collection for the Eastern U.S., donated his collection to the Buffalo Museum.