Millions of years ago, when huge dinosaurs stomped across Earth, little creepy crawlies were scurrying at their feet. Now, researchers have discovered a brilliantly preserved example – a tiny millipede frozen in time encased in vibrant amber.
The 8.2-millimeter beastie, which was discovered in Myanmar, is so unique that scientists have had to shake up the millipede family tree, giving the ancient arthropod its very own suborder. It lived 99 million years ago during the Cretaceous period, an era when mosasaurs swam the seas and tyrannosaurs stalked the land.
The specimen is the first fossil of a millipede belonging to the order Callipodida ever found and is smaller than its relatives from the same era. It also sheds light on when Callipodida first came to be, suggesting that this group of arthropods must have evolved at least 100 million years ago.
The leggy critter has been named Burmanopetalum inexpectatum and is described in the journal ZooKeys. Burmanopetalum refers to Burma (now Myanmar) where it was found, and inexpectatum is Latin for “unexpected”.
“It came as a great surprise to us that this animal cannot be placed in the current millipede classification,” said lead author Professor Pavel Stoev in a statement. “Even though their general appearance has remained unchanged in the last 100 million years, as our planet underwent dramatic changes several times in this period, some morphological traits in Callipodida lineage have evolved significantly.”
To study their specimen, the scientists used 3D X-ray microscopy, which allowed them to look at the millipede’s physical structure in impressive detail. The golden amber allowed it to retain features that would be lost in normal fossils.
Amazingly, the piece of amber in which the specimen was encased actually contained a total of 529 millipede fossils. B. inexpectatum, however, was the one that stood out, being the only member of its order within this mishmash of millipedes.
"The entire Mesozoic Era – a span of 185 million years – has until now only been sampled for a dozen species of millipedes, but new findings from Burmese amber are rapidly changing the picture,” said study co-author Dr Thomas Wesener. “In the past few years, nearly all of the 16 living orders of millipedes have been identified in this 99-million-year-old amber. The beautiful anatomical data presented by Stoev et al. show that Callipodida now joins the club."
“We were so lucky to find this specimen so well preserved in amber!” added Stoev.