Ancient wingless wasp
One of a kind - ancient wingless wasp (now extinct). Image credit : Oregon State University
Plants and Animals

One of a Kind, Ancient Wingless Wasp Found

Hukawng Valley in Myanmar on the continent of Asia has one of the richest deposits of arthropods found in amber from the Cretaceous period, with 252 families found so far. The latest fossil found by a team from the College of Science at Oregon State University is a strange, parasitic wasp without wings.

The wasp, preserved in amber more than 100 million years old, belongs to no other family ever identified on Earth, although different parts of its anatomy looks similar to those of other insects. The wasp is amazingly well preserved and scientists speculate that it crawled along the ground at the base of trees trying to find other insects and a place to lay its eggs. It however eventually disappeared and is now extinct. This could have been due to pathogens or habitat loss, or maybe because it couldn’t fly.

After substantial debate, mentioning first one body part and then another, researchers eventually decided to create a new family for the specimen, called Aptenoperissidae. This new family is part of the larger Order of Hymenoptera, which includes modern wasps and bees. Within that family, this wasp was named Aptenoperissus burmanicus and it is now the only known specimen.

George Poinar, Jr., one of the world’s leading experts on plant and animal life forms found preserved in amber, did not know what he was looking at when first seeing the insect. Poinar, who is co-author on the study, explained that although it was obvious that it could give a painful sting and was robust and tough, it simply did not fit anywhere and a new family had to be created for it. It ultimately dying out created an evolutionary dead end for that family.

When various researchers and reviewers, each with their own frame of reference, looked at the fossil, many saw something different. If you focused on the antenna, it looked like an ant. Its strong hind legs looks like a grasshopper’s and the thick abdomen like a cockroach. The team finally decided it had to be some kind of Hymenoptera because the face looks mostly like a wasp.

The insect possibly burrowed into cavities to seek pupae of other insects into which to lay its eggs. It is female and has long legs that were used to help pull it out of the cavities. If this were the case, wings would have been a hindrance. Researchers also speculate that it may have attacked other beetles with its sharp and jagged stinger, while its strong hind legs gave it a strong leaping ability. It did have a cleaning device on the tip of its antenna that is typical of Hymenoptera.

The findings have been published in the journal Cretaceous Research.