Amber with ticks from the Cretaceous found in Myanmar
The new study is based on Burmese amber pieces from the Cretaceous which show an open window to visit the world of feathered dinosaurs. In the study, experts analyse a Burmese amber piece from the Cretaceous which had a fossil tick -a model of Cornupalpatum burmanicum, an extinguished species- stuck to the feather of a theropod dinosaur.
“This finding is important because it is hard to find fossils of blood-feeding parasites directly related to the remains of their host. Also, this model of hematophagic parasite is the oldest one known so far in the parasitism between arthropods and vertebrates” says Xavier Delclòs (UB-IRBio). The article is also signed by Enrique Peñalver (Geological and Mining Institute of Spain, IGME); Ricardo Pérez de la Fuente (University of Oxford, United Kingdom), David Grimaldi (American Museum of Natural History, United States), Antonio Arillo (Complutense University of Madrid) and David Peris (Jaume I University, UJI), among other experts.
According to Enrique Peñalver (IGME), main author of the study, “ticks are blood-sucking parasites, and can affect the health of humans, livestock, pets, and wild animals. However, there was not scientific evidence on their role over evolution so far”. The short life of yje complex DNA molecule, made the recovery of dinosaursʼ genetic material impossible, a sophisticated technique that inspired successful movies to take back the main characters of the Secondary Era on Earth.
When ticks feed from dinosaursʼ blood 100 million years ago
The findings of feathers on the fossil records are not common but there have been some remains identified in sites worldwide. “The fossil record points out that feathers such as the ones in this study were present in a wide range of theropod dinosaurs, a group covering from terrestrial creatures unable to fly to bird-like dinosaurs that could fly” says Ricardo Pérez de la Fuente, researcher from the Oxford University Museum of Natural History.
“Therefore -he continues- despite not completely knowing which feathered dinosaur this tick was feeding from, the dating of the Burmese amber from the Cretaceous verifies that the feather did not belong to modern birds, since these appeared later in the evolution of theropods, according to the current fossil and molecular evidence”.
Discovering the Dracula Bug
In another Burmese amber piece, researchers found a blood-swollen tick (eight times bigger than bloodless models) from a close family to that of C. burmanicum, corresponding to corresponding to a new species, Deinocroton draculi. Unlike Cronupalpatum burmanicum, this new fossil from the extinguished family of ticks Deinocrotonidae -also noted in this study- was not directly associated to its host.
“It was not possible to determine the composition of the blood intake by this thickened tick. Unfortunately, the parasite did not completely sink in the resin and its content was altered due the mineral deposition” says Xavier Delclòs, lecturer from the Department of Earth and Ocean Dynamics of the UB.
However, the appearance of remains of specialized setae from beetle larvae -in particular, dermestidae coleoptera- in the legs of ticks from the Deinocrotonidae family is an indirect trace suggesting that feathered dinosaurs, ticks and beetles would cohabit -probably within a common reduced space- where they got caught by resin. “The simultaneous capture of two external parasite species -ticks- is an extraordinary fact, and can be better explained if considering they are organisms sharing a common habitat like some current ticks do, which live in the host nest or nearby” concluded David Grimaldi, from the American Museum of Natural History.
The authors remember birds are the only descending lineage from theropod dinosaurs that survived the massive extinction from the late Cretaceous, while nowadays ticks are still parasitizing and transmitting diseases to different living beings.