Dino-feasting tick found in ancient amber

Now dinosaurs have ruled the planet for hundreds of millions of years, but they weren’t immune to being preyed upon themselves by parasites, and now scientists have discovered an ancient tick clinging to a 99 million year-old dinosaur feather trapped inside a lump of fossilised tree resin. Georgia Mills spoke with discoverer Ricardo Perez-De-La Fuente from the Oxford Museum of Natural History…

Ricardo - We present the first direct evidence of a parasite/host relationship between ticks and feathered dinosaurs. We have a tick that is grasping a feathered dinosaur in Burmese amber which is 99 million years old. We also have described additional ticks that belong to a new group of ticks - an extinct group of ticks that went extinct, probably at the end of the Cretaceous, so those are the two main findings.

Georgia - I’m quite familiar with ticks that exist now: I have to take them off my dog when she’s run through shrubbery. Is this tick similar to what we’d see today; what is it?

Ricardo - Yes. Actually, that tick is an immature tick. It’s about 1mm in length and it belongs to hard ticks - so a modern group. Whenever we think about the classic ticks, hard ticks are the ones that come to our mind. They have this shield-like structure at their backs that mostly protect them from when the host is trying to scratch them off for instance. So the tick that is in the feather in the amber piece that we discovered and we described in this new paper, it’s very similar to modern forms. Actually, the tick can be classified as an already described species. This is the first time that a tick is found in direct association with remains of its host.

Georgia - Right. This is pretty strong evidence then that dinosaurs had to deal with these pests as well?

Ricardo - Yeah, absolutely. That’s actually the dream of paleontologists. 99% of the time we are always working with possibilities, and we use the morphology of the fossils to try to infer ecologies and behaviours of past organisms. But cases in which we can actually get access direct evidence by direct association, those cases are very very rare.

Georgia - What must have happened for you to get this brilliant snapshot of 99 million years ago?

Ricardo - Amber is fossilised resin, it’s sap from the trees that, with the passing of time, has hardened. But we can imagine the feather with a tick grasping to it got detached from its feathered host and got in contact with some resin flow. We don’t know if that happened on the trees, or above the ground, or at the forest floor at floor level. Because sometimes we can have resin becoming secreted high in the level of the branches of the trees so sometimes that resin falls on the ground, but that’s overall the scenario that we can picture.

Georgia - How did you get hold of this amber?

Ricardo - We had private collectors donating part of their collections to museums and through them we got to study them. I mention this because, actually, nowadays Burmese amber can be purchased online. It’s a good income source for the local sellers in Myanmar, so there are private collectors that have specialised in amber, purchasing this material, and some of them, luckily, are interested in their collections to be studied by scientists. So this had a happy ending, it’s one of those strange cases in which private collectors broke the barrier between themselves and scientists and, because of that, we got a very fruitful work.

Georgia - I’ve got to ask just because Jurassic Park is my favourite film: they find a mosquito in the amber and they bring dinosaurs back to life. Is anything you’ve got here enabled you to get any closer to the dream?

Ricard - Very well put! I would say that not in this case, unfortunately. Jurassic Park was based on a serious scientific study that had claimed to have extracted DNA from amber inclusions, but subsequent experiments were not able to replicate it. It must have been a contamination from modern DNA. Using modern techniques there is actually no way we can extract decently preserved DNA from amber inclusions. It seems that DNA is a very fragile molecule and degrades easily. So the message here is: not at this particular moment of time, but we need to keep dreaming about Jurassic Park - someday, perhaps.