Breaking the “Mummy’s Curse”

The challenge of turning mummified rodent remains into useful scientific specimens

Kenneth Bader is the preparator for the Vertebrate Paleontology Collections at the Jackson School Museum of Earth History.

The job entails collecting and cleaning the hundreds of thousands of specimens held in a three-story warehouse out at The University of Texas at Austin’s J.J Pickle Research Campus. Most of these specimens are fossils. But a growing part of the collection is much fresher, made up of bones from animals that have died relatively recently.

Bader occasionally brings in specimens himself, stopping by the side of the road to scoop up a snake  or javelina  that has met an untimely end. But for the most part, the bodies find him.

That’s the case for a collection of desert rodents made up of 19 pack rats, kangaroo rats, and mice. The rodents were caught during a 1959 trip to south Texas and Mexico led by Ralph Axtell, a professor at Southern Illinois University.  But the collection became “orphaned” without anyone to look after it when Axtell died in 2016. After passing through the Texas Natural History Collections, the rodents settled with Bader in the Jackson School’s collections.

Most of the bones that enter into the contemporary collections start off as meaty, intact specimens donated from local zoos and wildlife rehabilitation centers. Their flesh is stripped by the museum’s supply of dermestid beetles, and the resulting skeletons are then placed on the collection shelves.

These rodents are a different story. The bones are mummified –  the result of the skinned specimens being stored in a dry environment for decades – with flakes of long-dead tissue giving them a sandy appearance. And while a few are relatively intact, most of the bones are jumbled together in a mass of miniscule skulls, bones and leathery tails. The yellow identification cards that float among the mix are untethered from the specimens they were once affixed to.

Bader calls the entire concoction the “The Mummy’s Curse” – the curse being the tedious work that’s ahead of him. He is currently in the process of sorting through the bones, determining which type of rodent they belong to, and re-assembling the tiny skeletons.

Once complete, the skeletons will be added to the rest of the 15,000 (and growing) specimens held in the contemporary collections. From aiding in fossil identification, to helping map out where different species lived over time, modern bones can be a priceless tool when doing paleontological or biological work.

But before that can happen, Bader has to break the curse.

Bader has pulled two kangaroo rat skeletons from the collections to help with the identification process. The rodent’s distinct skull, with its bulbous heart-shaped back tapering into a narrow snout, is easy to pick out. But ribs, limbs, and vertebrae will take more work, and there’s no guarantee that some bones haven’t gone missing (potentially carried away by wild dermestid beetles) or disintegrated into dust over the years.

Adding to the challenge is the uncertainty that comes from human error. According to the field notes, the rodents were collected during a student field trip. And although the students diligently identified their caught specimens, it appears that, in some cases, they didn’t know their rats from their mice.

Nevertheless, Bader is confident he can make sense of most of the bones. And although the scrambled specimens may be a mess, he doesn’t really consider them a curse. Bader is a big fan of puzzles. He considers the rodent bones his latest one.

“It’s like a puzzle, it’s fun,” he said.  “And although it can be a little frustrating, I have learned over the years that data gets lost, information gets lost. You complete what you can, and move on to the next one.”