The first major undertaking of Carleton’s CARCAS lab was a multi-phase project conducted over winter break, dedicated to the establishment of a physical and digital repository of all of CARCAS’s specimens. The first phase of this project was the preparation and cleaning of the lab’s faunal specimens – that is, animal bones – in partnership with the Cowling Arboretum.
Mathew Zappa (he/him), a senior biology major and CARCAS lab member, spent his 2021 Winter Break visiting the Arboretum office four days a week to oversee the initial bone cleanings. More specifically, he maintained, fed, and monitored the dermestid beetle colony that cleans off newly acquired bones.
What are dermestid beetles? In short, flesh eating beetles, housed in the Arboretum office. Archaeologists and museums have been using these beetles for decades to clean off the little bits that remain on bones even after being butchered and cleaned by hand. These parts, which Mathew describes as the remaining “scraps and cartilage,” are completely cleared away by the colony, leaving the bone behind, perfectly intact. Yet these beetles are completely harmless to people, consuming only dead organic matter.
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A close up of the adults and larva. -
The beetles work on a specimen. -
The beetles work on a sheep skeleton. -
The beetles work on a full deer leg. -
The beetles eating a vulture skull.
Over the course of the winter, CARCAS’s dermestid beetle population has grown from 30 adult beetles to over 1,000. Mathew remarks that, in the beginning, it could take up to a week for them to work their way through a mouse skeleton. A month later, they could work through 3 full size adult deer bones in a day. And, over their few month tenure, these beetles have prepared many different specimens. Beginning with a full sheep skeleton at the beginning of the fall, they have now cleaned specimens ranging in size from mice and small birds to pigs and deer.
Once the beetles have had their fill, Mathew takes the bones back to the Archaeology Lab for a final degreasing before they are ready for whatever lies in store for them next. The bones will have many various uses. Some are sent back to the Arboretum office to contribute to student and professor research in the Arboretum, or are added to the Arboretum’s faunal collections. For CARCAS, these bones will form the foundation for a comparative osteological collection, used to help identify bones discovered in archaeological excavations. These bones will give us greater insight into how humans lived in the past and interacted with their natural environments.
The bones that will join CARCAS’s collection are sent downstairs, to Carleton’s Class of 1969 Makerspace, where Avery Blumenthal, the Digital Humanities Associates, and Aaron Heidgerken-Greene carry out the second phase of this project: Digitization.
Written by Sam Wege (’22), CARCAS lab member.