Fossils come in a wide variety of forms, from preserved bones to leftover (and sometimes enormous) footprints. Sometimes, though, they come in the form of a bug within a lizard within a snake, all perfectly preserved within a volcanic lake.
About 48 million years ago, an ancestral iguana was having a rather wonderful day in prehistoric Germany. It had just managed to ingest a rather colorful insect, after all, and who doesn’t like a good lunch? However, little did this scuttling Geiseltaliellus maarius know that it just consumed its last meal.
It was at this moment that a juvenile Palaeopython fischeri snake decided to strike. More related to modern boa than the python, this tree-dwelling snake slithered out from the shadows and pounced, managing to successfully gobble up both the lizard and its lunch.
Sadly, it must have got lost on the way back to its arboreal residence, because it fell into the Messel Pit, a formerly active volcanic lake spewing out highly acidic sulfur dioxide, suffocating carbon dioxide. If anything became overwhelmed by these gasses, it would have likely stumbled into the broiling, bubbling, liquid haze, and sunk down into oxygen-poor waters.
As described in the journal Palaeobiodiversity and Palaeoenvironments, this was how the story of the life of the snake, the lizard, and the bug ended. Thankfully for paleontologists, these anoxic and bacteria-depleted waters guaranteed that – along with a wealth of other clumsy lifeforms – the ancient triplets were immaculately preserved for tens of millions of years.
“It’s probably the kind of fossil that I will go the rest of my professional life without ever encountering again, such is the rarity of these things,” study co-author Krister Smith, a paleontologist at Germany’s Senckenberg Institute, told National Geographic. “It was pure astonishment.”
Although this meal-within-a-meal feature wasn’t immediately obvious at first glance, powerful CT (X-ray) scans were used to peer inside. The iguana-like lizard was successfully identified, but the bug’s species designation remains a mystery for now. Either way, it’s an utterly breathtaking fossil – one that reveals an ancient food chain of predators and their prey.
An interpretive sketch of the lizard (orange) and the bug (blue) fossils within the preserved snake (white). The bug was found within the abdominal cavity of the lizard. Smith & Scanferla/Palaeobiodiversity and Palaeoenvironments