Action in amber

How did tiny crawling soil dwellers get around during the early Miocene? If this snapshot in amber from the Dominican Republic is anything to go by, they hitchhiked. 

The fossil reveals a number of tiny arthropods called springtails (Collembola) still attached to the wings and legs of a large winged termite, while others are preserved as if gradually floating away from their host. 

In a paper published in the journal BMC Evolutionary Biology, researchers from the New Jersey Institute of Technology (NJIT), US, and Museum national d’Histoire naturelle, France, say the discovery highlights the existence of a new type of hitchhiking behaviour among wingless soil-dwelling arthropods.

It also could help explain how symphypleonan springtails (one of three main groups) successfully achieved dispersal worldwide.

“The existence of this hitchhiking behaviour is especially exciting given the fact that modern springtails are rarely described as having any interspecific association with surrounding animals,” says NJIT’s Ninon Robin, the paper’s first author.

Springtails are among the most common arthropods found in moist habitats around the world. Most use a special appendage under their abdomen to “spring” away to avoid predation. 

However, this organ is not sufficient for traversing long distances, the researchers say, especially since most springtails are unable to survive long in dry areas.