by Timothy A. Pearce and Rachel Thomas Beckel
What do we mean when we say we have type specimens in the Carnegie Museum of Natural History (CMNH) collections?
Type specimens are (usually) the specimen(s) a person describing a new species looks at as they write the description (it’s this tall, this wide, this color, sculptured with bumps like this, etc.) and type specimens are the official name bearers for the whole species.
There are many kinds of type specimens, but the most important kind is the holotype. Paratypes (other specimens the original describer believes are the same new taxon) are also important, but holotypes are the most important. Two other kinds of type specimen are lectotypes (selected from the paratypes if the holotype is lost) and neotypes (selected from any specimen if all type material is lost). Every time we add another holotype it bolsters the significance of CMNH’s already significant collections. It raises our visibility on the “radar” of researchers and puts us on the map for that taxon.
Carnegie Museum collaborator Dr. Aydin Örstan recently named a new subspecies of snail Albinaria coa tek (Örstan & Yildirim 2023). He deposited the holotype and 12 paratypes of the new subspecies in the Mollusks collection at CMNH.
If a researcher wants to know if they have found another specimen of Dr. Örstan’s new subspecies, they could read his description. However, to be absolutely sure, a researcher might need to compare their finding to the type specimen.
Think of types as the gold standard. Because of their importance to nomenclature and taxonomy (the science of naming species), most museums (including CMNH) keep their type specimens securely locked in a special cabinet.
With regard to this land snail holotype, for Carnegie Museum to have the holotype of Albinaria coa tek means that people studying that subspecies or closely related taxa might need to travel to the museum to examine the type specimen or ask for additional information about it. For their research paper to be complete, they would need to refer to that holotype specimen. In addition to the holotype, Dr. Örstan gave CMNH paratypes of Albinaria coa tek, which can be important for understanding the range of variation in the subspecies.
Albinaria are land snails that occur in SE Europe and the Middle East and are typically found on limestone. In some cases, they appear to have been able to form new colonies when ancient humans moved limestone around for buildings (the snails likely hitchhiked on the limestone blocks). That means we can trace trade routes over which ancient humans were moving limestone.
The family Clausiliidae (which contains the genus Albinaria) are of interest because they bear a clausilium, a kind of door for closing the shell (hence the common name “door snails”), which is unique to the family and is very different from the operculum, which is a different kind of door in many sea snails and some land snails. Furthermore, most snails in the family Clausiliidae coil counterclockwise, which is the opposite direction of more than 99% of all other snails. Additionally, Clausiliidae have a peculiar global distribution, being found in western Europe, Eastern Asia, and northern South America. People who study biogeography (how species came to be living where they are now) scratch their heads wondering how Clausiliidae came to be living in those three separate places without any individuals being found in between – for example, if they migrated from Europe to northern South America, why don’t any Clausiliidae occur in North America?
In addition to this new holotype (and paratypes) in the Section of Mollusks, holotype specimens of new species of vertebrates and paratypes of a new species of insect were named in 2023 and deposited in the relevant sections of the CMNH collection:
Pietro Calzoni, from the Universitá di Padova, Italy, and colleagues designated a CMNH Vertebrate Paleontology fossil as the holotype of a new bony fish species, Rhamphosus tubulirostris (Calzoni et al. 2023).
Three new species of the insectivore mammal genus Plagioctenoides (P. cryptos, P. dawsonae, and P.goliath), and one new species of Cuetholestes (C. acerbus), were recently named from CMNH Vertebrate Paleontology fossils (Jones and Beard 2023).
A CMNH Vertebrate Paleontology gekko fossil was designated as the holotype of Limnoscansor digitatellus (Meyer et al. 2023). CMNH visitors can view this specimen on display in the Solnhofen case in the Dinosaurs in Their Time exhibition.
A male and six female moths from the CMNH Invertebrate Zoology collection were named the new moth species Meganaclia johannae (Ignatev et al. 2023). The moths were collected between 1918 and 1925 in Cameroon and were housed in the Invertebrate Zoology collection awaiting discovery as new species.
While CMNH welcomes hundreds of thousands of visitors per year to the public galleries, scores of researchers work behind the scenes to expand our understanding of the different kinds of organisms, as evidenced by their type specimens, that are present in our incredible world. As the moth example demonstrates, Carnegie Museum of Natural History (and other museums around the world) hold specimens that have yet to be recognized as new species!
Timothy A. Pearce is Curator of Mollusks and Rachel Thomas Beckel is Administrative Coordinator for Science & Research at Carnegie Museum of Natural History.
References
Calzoni, P., J. Amalfitano, L. Giusberti, M. Carnevale, and G. Carnevale. 2023. Eocene Rhamphosisdae (Teleostei: Syngnathiformes) from the Bolca Lagerstätte, Italy. Rivista Italiana di Paleontologia e Strigrafia, 129(3): 573-607.
Ignatev, N., G.M. László, A. Paśnik, Z.F. Fric, H. Sulak, and G.C. Müller. 2023. Five new species of the genus Meganaclia Aurivillius, 1892 (Lepidoptera: Erebidae: Arctiinae: Syntomini). Zootaxa, 5296: 457–474.
Jones, M., and K.C. Beard. 2023. Nyctitheriidae (Mammalia, ?Eulipotyphla) from the Late Paleocene of Big Multi Quarry, southern Wyoming, and a revision of the subfamily Placentidentinae. Annals of Carnegie Museum, 88(2): 115-159.
Meyer, D., C.D. Brownstein, K.M. Jenkins, and J. Gauthier. 2023. A Morrison stem gekkotan reveals gecko evolution and Jurassic biogeography. Proceedings of the Royal Society B., 290: 20232284.
Örstan, A., and M.Z. Yildirim. 2023. A new insular land snail, Albinaria coa tek Örstan, from Marmaris, Türkiye (Clausiliidae: Alopiinae). Archiv für Molluskenkunde, 152(2): 175-182.
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Carnegie Museum of Natural History Blog Citation Information
Blog author: Pearce, Timothy A.; Beckel, Rachel ThomasPublication date: May 2, 2024