Abstract

A slab of shale collected from the Parachute Creek Member of the Green River Formation contains what are interpreted as the remains of the contents of a spider web. The web itself is not visible, but the type and relative position of the 90 insects and 2 spiders in such close association leave little doubt that this death assemblage is evidence of a spider web. This specimen shows that most of the insects caught by the spiders are of approximately the same size as or smaller than the larger of the two spiders. Many of the insect remains are fragments, which are interpreted as the results of the spiders feeding. The slab contains specimens of the following orders of class Insecta: Diptera, Neuroptera (this order is not previously known earlier than the Miocene in North America), Coleoptera (one previously undescribed species), and Hymenoptera. The spiders are previously undescribed.