Ticks Trapped in Amber Were Likely Sucking Dinosaur Blood

Sunday, December 17, 2017

An image of a 99-million-year-old tick, enlarged at inset, grasping a dinosaur feather, preserved in amber found in Myanmar. Credit Nature Communications; Peñalver et al.

Paleontologists have found entombed in amber a 99-million-year-old tick grasping the feather of a dinosaur, providing the first direct evidence that the tiny pests drank dinosaur blood.

Immortalized in the golden gemstone, the bloodsucker’s last supper is remarkable because it is rare to find parasites with their hosts in the fossil record. The finding, which was published Tuesday, gives researchers tantalizing insight into the prehistoric diet of one of today’s most prevalent pests.

“This study provides the most compelling evidence to date for ticks feeding on feathered animals in the Cretaceous,” said Ryan C. McKellar, a paleontologist at the Royal Saskatchewan Museum in Canada who was not involved in the study. “It demonstrates just how much detail can be obtained from a few pieces of amber in the hands of the right researchers.”

Adult ticks, extant and preserved in ancient amber, compared to the tick nymph found attached to the dinosaur feather, above left. Scientists concluded that the tick nymph fed on a nanoraptor, a fledgling dinosaur no bigger than a hummingbird. CreditE. Peñalver

David Grimaldi, an entomologist at the American Museum of Natural History and an author of the paper published in the journal Nature Communications, was inspecting a private collection of amber from northern Myanmar when he and his colleagues spotted the eight-legged stowaway.

“Holy moly this is cool,” he recounted thinking at the time. “This is the first time we’ve been able to find ticks directly associated with the dinosaur feathers.”

Upon further inspection, he and his colleagues concluded that the tick was a nymph, similar in size to a deer tick nymph, and that its host was most likely some sort of fledgling dinosaur no bigger than a hummingbird, which Dr. Grimaldi referred to as a “nanoraptor.” The parasites were most likely unwanted roommates living in the dinosaurs’ nests and sucking their blood.

“These nanoraptors were living in trees and fell into these great big blobs of oozing resin and were snagged,” he said. Trapped too were the ticks. “We’re looking at a microcosm here of life in the trees 100-million years ago in northern Myanmar.”

They determined that the host was more likely a nonavian dinosaur and not a modern bird based on molecular dating, which suggested the specimen was at least 25 million years older than modern birds.

The team also reported finding a few more ticks in amber, including two that were covered in microscopic hairs belonging to a beetle. The team traced the origins of the beetle hair to a particular type of insect known as a skin beetle, which today lives in nests and scavenges on molted feathers as well as shedded skin and hair. In prehistoric times they most likely bothered dinosaurs in their nests.

The beetle hair suggested that the ticks lived in the same nests as the skin beetles. It provided indirect evidence that the prehistoric ticks infested dinosaurs, according to Ricardo Pérez-de la Fuente a paleobiologist at the Oxford University Museum of Natural History and an author on the paper.

They also found one tick that was engorged with blood, making it about eight times larger than its normal size. Dr. Pérez-de la Fuente said it was impossible to determine the host animal for that tick, and alas, he added there was no chance they could perform any Jurassic Park shenanigans by extracting its stolen blood.

Source: www.nytimes.com