Search the Community

Paleozoic insects can be extremely difficult for an amateur collector to identify. Partial specimens, poor preservation and outdated publications make it nearly impossible to identify most specimens to the species level. To further compound the problem, many species names are synonymous and no longer valid. In my future posts on Mazon insects, I will not attempt to identify specimens beyond the family level unless I have a firm identification. Geraridae are known from many Paleozoic sites around the world. The first Gerarus specimens were described in 1885 by Scudder from specimens collected from the Mazon Creek Deposit. While all Mazon insects are rare, they are one of the more commonly found types. Some of the defining characteristics are the four wings are similar in in length. The wings fold back over the thorax and abdomen.The prothorax is elongated and often times has large spiny projections. One interesting note is that it has been observed that the wing veination on Geraridae can be highly variable. It can even be different from wing to wing on the same animal! This has led to dozens of species being named. Many are synonymous and no longer valid. The largest recorded specimen size is 7.5 centimeters. I have one in my collection that is slightly larger measuring 8 centimeters. There has been much debate over the lifestyle of Geraridae. Current thinking is that they were not strong fliers and may be distantly related to crickets and grasshoppers. While Geraridae are known from Paleozoic sites worldwide, they are usually flattened and preserved as a thin film making study difficult. Mazon specimens can be found inflated exposing key structures not usually seen from other sites. Professor Jarmika Kukalova-Peck extensively studied Mazon Creek insects. She used Gerarus specimens from Mazon Creek to formulate her hypothesis of the origin of insect wings. The hypothesis is still debated and much more work needs to be done. This first specimen was collected from Pit 4 (Shadow Lakes). It has wonderful preservation and is the largest known specimen that I am aware of. Jarmila Kukalova-Peck studied this specimen and thought it might be a new genus. She also figured the specimen to determine various structures and wing veination.