CHAMPAIGN, Ill. A 115-million-year-old fossilized wasp from northeast Brazil presents a baffling puzzle to researchers. The wasp's ovipositor, the organ through which it lays its eggs, looks a lot like those of present-day wasps that lay their eggs in figs. The problem, researchers say, is that figs arose about 65 million years after this wasp was alive.
A report of the findings appears in the journal Cretaceous Research.
The wasp belongs to the Hymenoptera superfamily known as Chalcidoidea, which parasitize other insects, spiders and some plants. The group includes about 22,000 known species and is estimated to contain up to 500,000 species.
"This is a tiny parasitic wasp, it's the smallest fossil wasp found in this particular deposit and it's the oldest representative of its family," said Sam Heads, a paleoentomologist at the Illinois Natural History Survey at the University of Illinois. "More importantly, it's possible that this wasp was fig-associated, which is interesting because it's Early Cretaceous, about 115 to 120 million years old. That's a good 65 million years or so prior to the first occurrence of figs in the fossil record."
Heads worked in collaboration with University of Portsmouth scientists Nathan Barling and David Martill.
The new findings demonstrate the value of studying insect fossils, Heads said.
"The fossil record of insects is very extensive both geographically and temporally. It goes back 415 to 420 million years and preserves the ancestral forms of a lot of the insects that are alive today," he said. "So it's a great resource for understanding insect evolutionary history and the distribution of insects across the planet in the past."
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign