Why is this dung beetle rolling a dead lizard around?

Most of us recognise dung beetles for their propensity for pushing poop from A to B, but a recently viral video shows one of the iconic critters opting for bigger cargo. (You'll want to go HD on this one.)

The clip has been shared over 400,000 times since the Invertebrate Studies Institute posted it to its Facebook page, but the original was actually shot by Pakistan resident Shuja Jan back in 2012. Jan spotted the lizard-rolling beetle in Nushki, a small town in the country's Balochistan province.

We've reached out to several dung beetle specialists (yes, that's a thing!) to find out more about the beetle's odd "ball", but while we await more information, let's break down what we do know.

Dung beetles fall mostly into two groups: the subfamilies Scarabaeinae and Aphodiinae. There are over 5,000 known species (and counting!) in Scarabaeinae alone, and we're only just starting to figure out how many of them reside in the area where this footage was filmed. However, a 2014 review and survey found that one "particularly massive" species, the black beetle Catharsius platypus sharp, had set up shop in Balochistan.

That doesn't necessarily make this the ID for our reptile-rolling friend, but it's possible that the beetle in Jan's video is at least a relative.

While some online commenters jokingly suggested the lizard had simply enjoyed one too many sips from the local cacti, the reptile is undoubtedly dead. That said, the exact circumstances surrounding the beetle's "haul" are a bit unclear.

Dung beetles prefer to dine on a diet of herbivore excrement, but at a pinch, they'll pick up whatever form of faeces they can find. Some species, like Coprophanaeus lancifer, do bury carcasses from time to time. It seems somewhat unlikely* that the beetle planned to eat the large lizard, but its body may have provided a suitable depository for dung beetle eggs. (Nothing says "welcome to the world" quite like raising the kids in a bed of rotting flesh.)

We'll be updating this article as we get expert feedback, but if you've seen this behaviour before, we want to hear from you!

Want to learn more about dung beetles? Here's more than you ever wanted to know.

* UPDATE (JUNE 11, 2017):

Lund University associate professor Dr Emily Baird, who has done extensive work with dung beetles, told us that this individual would have fed on its supersize spoils, much to our surprise.

"What an amazing video!" she said. "The beetle will most likely dig a large hole and bury the lizard underground where it will stay and eat it until it is gone (this would take maybe a week or so)."

If egg-laying had been the plan, we would have seen a pair of beetles working together to move the carcass, she explained.

"As there was no other beetle, it is very unlikely that eggs would be laid so it is more likely just a good source of food! I have seen a beetle burying a snake once in order to eat it but the snake was too big for the beetle to move so the beetle just dug a hole under the body."