Scientists have long suspected that ticks feasted on the blood of dinosaurs, and now they've uncovered the first direct evidence. Preserved in a 99 million-year-old chunk of amber lies a hard tick grasping the feather of a dinosaur, suggesting that the parasitic insects did indeed harbor a penchant for prehistoric plasma.
Amber, or fossilized tree resin, from the Cretaceous period is proving invaluable for paleontologists studying the life and times of prehistoric animals. Last year, for example, one of these little golden time capsules turned up a preserved tail of a feathered dinosaur, complete with feather, bone and other tissue intact.
And amber has done a marvelous job of preserving insects too, including bizarre, alien-like critters and indeed blood-engorged ticks. But fossilized ticks actually caught interacting with their hosts is very rare. Way back in 2001, for example, scientists found a 90-million-year-old tick fossilized in amber that they deduced had fed on dinosaurs, but only because of its age.
The new discovery, made by an international team of researchers, leaves scientists with little doubt about ancient ticks' blood-sucking ways. Sealed away inside the 99-million-year-old Burmese amber is a Cornupalpatum burmanicum tick clutching at a feather, making it the oldest known fossilized sample of a blood-feeding creature interacting with its host. And the timing of all this is key.
"The fossil record tells us that feathers like the one we have studied were already present on a wide range of theropod dinosaurs, a group which included ground-running forms without flying ability, as well as bird-like dinosaurs capable of powered flight," explains Dr Ricardo Pérez-de la Fuente, a research fellow at Oxford University Museum of Natural History and one of the authors of the study.
"So although we can't be sure what kind of dinosaur the tick was feeding on, the mid-Cretaceous age of the Burmese amber confirms that the feather certainly did not belong to a modern bird, as these appeared much later in theropod evolution according to current fossil and molecular evidence."
Fans of Jurassic Park will be familiar with the underlying premise of its dinosaur revival, where DNA is extracted from a fossilized mosquito and used to bring the creatures back from the dead. Unfortunately, the scientists won't be getting up to such antics with their newly discovered specimen, simply because in real life amber doesn't do a good enough job of preserving the short-lived DNA molecules.
The scientists found further, separate evidence of ticks feasting on dinosaur blood, albeit indirect. This new species, which they've dubbed Deinocroton draculi, or "Dracula's terrible tick" was also encapsulated in Burmese amber, with one engorged with blood and bloated to eight times the size of the others.
While they have their suspicions, the team was unable to definitively determine the host animal, because the blood inside the tick had not been sealed away entirely by the amber and therefore its composition had been altered. But together with their feather-clutching cousins, these Dracula ticks make perhaps the most compelling case yet for an ancient, dino-blood feeding frenzy.
The research was published in the journal Nature Communications.
Source: University of Oxford via EurekAlert