Fossilized blood-feeding bugs have been discovered in early Cretaceous sediments in China. That means at least one lineage of bloodsuckers was around 30 million years earlier than we thought. They may have even fed from dinosaurs. According to the study published in Current Biology this week, the fossils represent two new species, and they’re the earliest evidence of blood-feeding “true bugs.”
True bugs (order Hemiptera) have a mouthpart designed for sucking fluids, called the proboscis. But unlike proboscis-wielding butterflies or honeybees, true bugs can’t roll up their mouthparts. Modern true bugs include nasty bed bugs. As annoying and ubiquitous as they seem, blood-feeders (also called hematophages) are relatively uncommon among modern insects. They’re mostly found in just four orders: lice, fleas, true flies (including mosquitoes), and true bugs. The latter three have been documented prior to the Cenozoic.
It’s been hard to tell hematophages apart from their non-blood-feeding relatives in the patchy insect fossil record. Until now, only one hematophagous true bug, Quasicimex eilapinastes, has been described, from mid-Cretaceous amber in Myanmar, about 100 million years ago.
Working in the early Cretaceous Yixian Formation of Northeastern China, a team led by Yunzhi Yao and Dong Ren of Capital Normal University in Beijing studied nearly 400 insects. In seven true bug specimens, they looked specifically for geochemical signals of iron, which indicates blood meals. By combining those findings with results with morphological and taphonomic (fossilization) data, the team placed three of the bloodsuckers into two new genera within a new family, Torirostratidae.
The other fossilized true bugs belonged to phytophagous (plant eating) families or predaceous families, which include assassin bugs who would liquefy the insides of their prey, before drinking them. Their iron concentrations were much lower.
They named one of the new true bugs Flexicorpus acutirostratus. That’s Latin “flexi” for “soft” and “corpus” for “body.” The species name is taken from Latin “acuti” for “sharp” and “rostratus” for “beaked.” It's less than 10 millimeters long, and here are some cool pictures:
They’re naming the other one, which is over 12 millimeters long, Torirostratus pilosus. That’s Latin “torosus” for “bulges” and “rostratus” for “beaked” (again). The species name is comes from Latin “pilosus,” which refers to its dense setae (stiff bristles).
One of the bugs appears to have died immediately following a blood meal, which may have been taken from a mammal, bird, or dinosaur, though the researchers can’t be sure. (Insert Jurassic Park joke here, bonus points for True Blood.)
Images: Y. Yao et al., Current Biology 2014