This Sicko Caterpillar Wears the Bones of Its Victims

Welcome back to the Abstract! 

Beware: This week’s offerings are not for the faint of heart. There will be blood. There will be gore. There will be death. There will be…honeydew? 

First stop is a gladiator cemetery, which has got to be one of the most haunted varieties of burial ground. There is very bad mojo at a gladiator cemetery! This one is no exception. Next, meet a very hungry caterpillar with a very grotesque fashion sense and behold a hell ant from the age of dinosaurs. 

If you make it through a cavalcade of horrors, you will be rewarded with some chimp sangria. Go forth and good luck! 

Are You Not Entertained? (Personally, I Am Not)

Thompson, T.J.U. et al. “Unique osteological evidence for human-animal gladiatorial combat in Roman Britain.” PLOS ONE.

Some 1,700 years ago, a young man of about 30 was publicly decapitated and fed to a lion during a gladiatorial event. That’s the speculative conclusion of a new study about the skeleton of this man, known as Individual 6DT19, which presents “the first physical evidence for human-animal gladiatorial combat from the Roman period seen anywhere in Europe.”

Gladiators have been a cultural obsession for thousands of years because, let’s be real, people are sickos. Spectators across the Roman Empire packed arenas to watch gladiators kill each other, or kill dangerous animals, or be killed by dangerous animals. You get the idea: Blood spilling on the arena floor and blood pumping in the stands. Sicko stuff.

Driffield Terrace, a Roman site near the English city of York, is packed with the bones of dead men that bear obvious signs of blunt force trauma, hinting that it might be a gladiator cemetery. Many of the bodies at Driffield Terrace are also decapitated, with the heads placed at the feet for burial. Individual 6DT19, who lived between 200 and 300 CE, is unusual in that his head, while still chopped off, was placed in the correct anatomical position. But what really sets him apart is his punctured pelvis, which looks like it was used as a chew toy. 

A 5th-century mosaic in the Great Palace of Constantinople depicting human-animal.

Now, researchers have re-examined the holes on this man’s pelvic bone with a 3D-scanner and concluded that they were probably made by a big cat with a taste for human flesh.

“It is proposed, based on the evidence from the archaeological, medical and forensic evidence, that the bite marks on 6DT19 derive from a large felid, such as a lion,” said researchers led by Tim Thompson of Maynooth University. “The location solely on the pelvis suggests that they were not part of an attack per se, but rather the result of scavenging at around the time of death. The decapitation of this individual was likely either to put him out of his misery at the point of death, or for the sake of conforming to customary practice.” 

The bite marks on 6DT19’s pelvis. Thompson et al., 2025, PLOS One, CC-BY 4.0 

In other words, this guy might have got off lucky; he was beheaded before he was thrown to the lions. Others were not so fortunate, as animals in these gladiatorial shows were used “as the agents of spectacular mutilation and execution of criminals, captives from warfare and other perceived deviants, including Christians, who were also sometimes forced to participate in such events, known as ‘damnatio ad bestias’,” the team said. “These would sometimes include the re-enactment of mythical narratives as executions.”

Blech, just evil stuff, though you can’t accuse it of lacking creativity. And though it’s unclear why 6DT19 was condemned to a public death, the new study does expose a fleeting glimpse of these iconic and brutal spectacles, which continue to live on in our modern imaginations. 

Personally though, when it comes to gladiators, I’ll take the spandex-clad TV stars of the 1990s over the gory Roman death matches any day of the week.  

The Bone Collector’s Lookbook 

Rubinoff, Daniel et al. “Hawaiian caterpillar patrols spiderwebs camouflaged in insect prey’s body parts.” Science. 

Amazingly, the tale of a man who was fed to a lion is not even the gnarliest study that was on offer this week. Enter the “bone collector,” a newly described species of carnivorous caterpillar that invades spiderwebs, eats the ensnared insects, and then wears their body parts like prized armor. 

“We have identified body parts belonging to more than six different families of insect attached to the silk caterpillar cases, suggesting that they are adaptable scavengers and predators,” said researchers led by Daniel Rubinoff of the University of Hawaii. “When decorating their silken portable cases, the caterpillars are particular. Body parts are carefully measured for size before the caterpillar weaves them into its collection. Each prospective new addition is rotated and probed with its mandibles several times, and parts that are too large are chewed down to a size that will fit its case.” 

In other words, the caterpillars are bedazzling themselves with the bodies of their victims. Imagine all of this unfolding from the point of view of an entrapped insect. You’ve already had the worst day of your life—you are cached spider chow—then you see a caterpillar methodically eating your cell mates and sewing their remains into a dapper outfit? 

But wait, it actually gets better:

“If denied access to arthropod body parts in captivity, the caterpillars do not accept other bits of detritus, suggesting that they recognize and exclusively use corpses in nature and that this decoration is important to their survival,” the team said. “Given the context, it is possible that the array of partially consumed body parts and shed spider skins covering the case forms effective camouflage from a spider landlord; the caterpillars have never been found predated by spiders or wrapped in spider silk.”

Gladiators, eat your heart out (assuming a lion hasn’t already done that).The caterpillars refuse to adorn themselves in anything other than dead bodies, which they use to avoid detection by “spider landlords.” Great animal, no notes.

Sadly, though, this species has only been observed in the forests of one mountain on the Hawaiian island of Oahu, and may be facing extinction. “Without conservation attention, it is likely that the last living representative of this lineage of carnivorous, body part–collecting caterpillars that has adapted to a precarious existence among spider webs will disappear.”

It makes you wonder how many weird, trippy species have already vanished without documentation. “Save the Bone Collectors” does not have the same ring as “Save the Whales” but nonetheless these macabre fashion mavens deserve a helping hand—especially a disembodied one that they can wear.

The Deadest Ant

Lepeco, Anderson et al. “A hell ant from the Lower Cretaceous of Brazil.” Current Biology.

Hold onto your butts, because we’re not done with grisly insects yet. Our next entomological curiosity is a fossilized “hell ant” that lived an astonishing 113 million years ago, making it “the oldest definitive ant known to science and also the most complete evidence for the early evolution of ants in the fossil record,” according to a new study.

The exquisitely preserved ant was discovered in Brazil’s Crato Formation and represents a new species called Vulcanidris cratensis. It is at least 10 million years older than the next unambiguous ant fossils, pushing the timeline of ant evolution deeper into the Cretaceous period and shedding light on the first radiations of ants during the age of dinosaurs.  

Dead ant. Image: Anderson Lepeco

“​​As part of this initial radiation, hell ants of the subfamily Haidomyrmecinae are arguably the most fascinating group discovered to date,” said researchers led by Anderson Lepeco of the Universidade de São Paulo. “They are readily recognized by their bizarre scythe-like mandibles, often pointed upward and coupled with facial projections, representing unparalleled morphologies in the context of modern ants. Many hypotheses have been raised to explain their anatomical uniqueness, including prey impaling, clasping, or even honeydew collection.”

Wow, there’s a real vibe shift between impaled prey and collected dew. These ants have range. Indeed, the discovery of this new species demonstrates that hell ants had “achieved a wide geographical distribution during the Cretaceous, spreading through Laurasia (i.e., Canada and France) and South America,” according to the team. Though they went extinct along with the dinosaurs, may they live on forever in our nightmares.

Boozy Breadfruit, Family Style 

Bowland, Anna et al. “Wild chimpanzees share fermented fruits.” Current Biology.

Lion bites, bone outfits, and exhumed hell ants. It’s time for a drink. The special this week is a fermented African breadfruit that has been left in the Sun too long. At least, that’s what’s being served at chimpanzee cocktail bars, according to a study this week that presents “the first evidence for ethanolic food sharing and feeding by wild nonhuman great apes” (also known as a booze-up).

“The use of fermented foods and drinks by humans is so widespread as to be considered ubiquitous, with their use largely linked to dietary benefits and social bonding,” said researchers led by Anna Bowland of the University of Exeter. “However, little is known about the inclusion of ethanolic foods in the diet of nonhuman great apes.” 

You know what that means: Time to party with some chimps. The team observed troops of wild chimpanzees sharing fermented breadfruit in Cantanhez National Park, Guinea-Bissau. The alcohol content of the fruits is about 0.61 percent, similar to kombucha, so it’s not like the animals are getting obliterated. Still, the consumption of alcoholic beverages in friendly group settings suggests that humans aren’t the only apes that bond and unwind over libations.

Chimps sharing fermented breadfruit. Image: Bowland et al.

“Chimpanzees were seen to regularly select and feed on T. africana fruits when available (70 events),” the team said. “Sharing was observed on 10 separate occasions…between 17 individuals across all age- and sex-classes. Nine of ten sharing events were ‘passive’ (i.e., a possessor tolerates feeding from the fruit but does not facilitate its transfer), with one event classed as ‘active–passive’, whereby the possessor tolerated the taking of a food portion held in their mouth.”

I admire the gumption of the chimp that grabbed spiked breadfruit out of its companion's mouth, and I appreciate the tolerance of the chimp that allowed it. The team concluded that “the use of alcohol by humans is not ‘recent’ but rather rooted in our deep evolutionary history,” according to the study. Whether you imbibe or abstain, here’s a toast to the happy hours of prehistory.

Thanks for reading! See you next week.