Back in the fall of 2021, a group of cavers returned to Lee County, where they had come across something unexpected on a mapping trip five years earlier. This time accompanied by paleontologist Alex Hastings, they worked tirelessly – and muddily – to bring to light “Petra,” “the near-complete skeleton of an ice-age era cat.”
Spending 30 hours in two days traversing 40-foot vertical drops, bottomless pits and muddy crevices to extract the ancient bones from a cave deep in the Washington and Jefferson National Forests was quite the arduous feat. Yet, this endeavor was only the beginning of a much longer process of preparing and discovering all there is to know about Petra – one that is still far from finished today, over a year later.
Petra’s home is now the Virginia Museum of Natural History in Martinsville in the lab of Lucy Treado, a paleontology technician, whose primary task since the skeleton was brought to her in October has been to separate the bones from the matrix, the mineral crust that forms around fossils.
“If we’re not careful when we go to remove those crystals, we take that top layer of bone with it because that bone is a lot softer than what we’re used to working with,” said Treado. “So it’s been pretty slow-going.”
Slow-going indeed. With a true crime podcast playing over the soft whirring of a micro jack, Treado estimates that she has devoted roughly 1,000 hours working to free Petra from its sedimentary prison so far. This does not include the time that paleontology volunteer Alicia Lantz has also spent clearing Petra’s front legs, three days a week for several months. Their tedious hours in the lab are paying off, however, as around half of the skeleton is cleared including the skull and almost all of the legs.
But there are still more challenges ahead.
“The hardest section is probably going to be the shoulder blade area,” said Treado. “The shoulder blades are pretty thin and it’s just a complete jumble. We did have Petra CAT-scanned with the local hospital and, with all of the data, that [the shoulder area] is the least clear. It’s hard to tell what is exactly underneath the matrix. I’m kind of saving that one for last because I’m kind of dreading it. It’s just a whole bunch of broken ribs and I think one of the shoulders is not where it’s supposed to be so it’s scary going in because you feel like you’re going in blind.”
Thankfully, paleontologists seem to have more patience than most.
“I’m just trying to get tiny, tiny pieces off at a time,” Treado explained. “If I try to remove too much at once it can cause some pretty severe damage to the skeleton.”
Though the discovery team was forced to make some “strategic breaks” under Hastings’ supervision in nine places in order to extract the skeleton from the narrow crannies of the cave, later examination revealed some preexisting broken limbs that may provide some more answers about the animal’s death.
The radius and ulna of the front right leg sustained shaft fractures, which are commonly found in modern cats that have either been hit by a car or experienced a long, hard fall – the latter seeming more reasonable in Petra’s case. The cave contains two key, steep drops – one of which is near the cave entrance – as well as several others and “has not dramatically changed from the time when Petra was alive,” according to Hastings. The research team’s theory is that after suffering an injury, the cat traveled further into the cave in an attempt to escape but was unable to find another way out.
“That [drop] could have very easily accounted for breaking a limb and making it a lot more difficult to get out of even though it would have been almost impossible anyway even for a really agile cat,” said Hastings.
The cavers came across the animal lying with its right side up so the left half of the skeleton was preserved in the mud. The minerals that now encase the exposed bones provided a layer protecting from the cave environment, keeping Petra’s skeleton in relatively good condition for tens of thousands of years. A majority of these were deposited onto the right side of the skull by water dripping off the ledge above the cat.
While the months spent studying the bones have answered a few of the researchers’ questions, there are still a slew that remain unconfirmed, particularly in terms of identification of Petra’s sex, age, diet and specific species, according to Hastings. There are some concerns that given the millenia that Petra has spent in the cave the chemical bonds holding the molecules of the bone together will have degraded too much to determine exact dates and other facts.
“Whatever you find starts meaning less and less as time goes by,” explained Hastings. “And in the case of Petra, that water going over the skeleton was taking away the original stuff and putting new stuff in. That makes it more difficult to determine how old chemically.”
For example, Treado recently sent out a rib fragment for carbon dating, but was unable to get a date. However, the team is hopeful that they will find more success in testing one of the cat’s teeth. This will have to take place after Treado’s work is completed so they can study the intact skeleton and create models as the carbon dating process is destructive to the sample.
All of the hours spent peering through a microscope and chipping away on the bones will pay off, as the Virginia Museum of Natural History has many plans in store for the skeleton, such as an early education center where they hope to replicate the cave layout including a replica of how Petra was found laying in the mud. The actual bones will be on display in the museum as well, while 3D-printed versions will travel around as an educational tool.
“I’m super excited about the outreach with this,” said Hastings. “I really want to bring 3D printed Petra everywhere and tell people about this cool cat that had this great story in Virginia.”