Rare Eocene Marsh Fly Fossil from Wyoming

More than 51 million years ago, this Marsh Fly (Plecia pealei) flew above the quiet freshwater lakes of the Eocene Epoch. When it eventually settled into the still waters below, it was gently covered by fine sediment, beginning an extraordinary journey that would preserve it through deep time and into the present day.

Specimen Details

Species: Plecia pealei (Marsh Fly)
Age: Eocene (~51 million years old)
Formation: Green River Formation
Location: Kemmerer, Wyoming, USA
Specimen Size: Approximately 52mm × 42mm × 8mm
Fly Size: Approximately 12mm × 12mm
Weight: 30 g
Authenticity: 100% Authentic natural fossil
Display: Excellent collector, educational, or gift specimen

This authentic fossil was collected from the legendary Green River Formation, one of the world's finest fossil localities. During the Eocene, this region was covered by a series of calm lakes where layer upon layer of ultra-fine sediment accumulated on the lake floor. These sediments rapidly buried plants, fish, insects, and other organisms, protecting them from decay before gradually hardening into limestone over millions of years.

Today, the Green River Formation provides one of the most complete records of an ancient freshwater ecosystem anywhere in the world. Its remarkable preservation has made it internationally famous among scientists and fossil collectors alike. While fossil fish are the formation's best-known treasures, insect fossils such as Plecia pealei are less frequently discovered and offer a fascinating glimpse into the diverse insect life that thrived in these subtropical landscapes.

This Marsh Fly is more than a fossilit is a genuine survivor from a world long gone. Whether displayed in a collection, used as an educational specimen, or given as a memorable gift, it is a timeless reminder of Earth's incredible natural history.