This amber nugget from Myanmar holds the first known baby snake fossil

The first known fossil remains of a baby snake have turned up in a hunk of amber found in Myanmar. The critter, a new species named Xiaophis myanmarensis, met its untimely demise about 99 million years ago, during the Cretaceous Period, an international team of researchers reports July 18 in Science Advances.

How do we know it’s a baby?

First, it’s tiny. The skeleton, which is missing its skull, is about 5 centimeters long. In total, the snake was probably less than 8 centimeters. Plus, its incomplete bone formation matches what’s seen today in neonatal snakes.

Really? Nobody has found a fossilized baby snake before?

The fossil record for snakes has been notoriously sparse until about the last 20 years, says coauthor Michael Caldwell, a paleontologist at the University of Alberta in Edmonton, Canada. Snakes don’t preserve well in general. And this baby is especially delicate, with 97 wafer-thin vertebrae packed into just 47 millimeters of skeleton.

“Even if something that small was preserved in the fossil record, in normal fossil preservation styles, you’d never find it,” Caldwell says. Sedimentary rock would crush fragile remains and separate vertebrae, which individually would be nearly impossible to identify. It’s only because this snake had the misfortune to get caught up in sticky amber sap that its skeleton has been so exceptionally preserved in 3-D. 

What can it teach us?

This fossil, plus skin from a larger snake of a different species, offers the first evidence that some Cretaceous-era snakes lived in forests. That’s not necessarily a surprise, Caldwell says. By then, snakes were distributed broadly around the world. But other snake fossils don’t always have enough clues to ID the animal’s habitat. Because amber oozes from a tree, anything preserved inside it must have lived nearby.