279 — A Burmese amber tick wrapped in spider silk

Fossilized spider silk is rare. Fossilized ticks are rare. Modern spiders eating modern ticks is rare.

So this fossilized tick wrapped in spider silk and then encased in amber is quite a find.

These paleontologists found this tick wrapped thickly in spider silk, though the source of the silk was nowhere to be found. This suggests that the spider possibly did not wrap the tick with the intention of eating it, but instead wanted to immobilize the tick which had probably wandered onto the web and was causing a hullabaloo. (This sort of immobilization behavior is common in silk-producing modern spiders as well.)

Because tick predation by web-producing spiders is so rare in the fossil record, at first it was not clear whether this fibrous material was indeed spider silk, or perhaps instead fungal hyphae that grew on a decaying carcass. But the strands show patterns common to spider immobilization “weaves,” and furthermore the tick is not in a likely position for a natural decomposition.

This is a very exciting specimen both because it represents ticks in the fossil record, and because it demonstrates a relationship between Cretaceous spiders and Cretaceous ticks.