ANATOMICALLY PRESERVED CATERPILLAR COPROLITES FROM THE MIDDLE MIOCENE YAKIMA CANYON FLORA OF CENTRAL WASHINGTON STATE, USA

Anatomically preserved caterpillar coprolites with distinctive six-sided, segmented morphology are described in association with the middle Miocene permineralized "bog" flora of Yakima Canyon, Washington state, USA. These specimens are similar to ones illustrated by Lan'cucka-Srodoniowa from the Miocene of Poland that were described originally as fruits of the family Araliaceae (ivies, ginseng). These six-sided structures, and others from additional sites in the Tertiary of Europe, lack the organization and structure of fruits. Upon sectioning the Yakima Canyon specimens we found they too lack anatomical plant structure and instead are made up of fragmented plant remains. The larger of the two specimens is approximately 5.0 mm long and 1.5-2.0 mm wide. In cross section they show six prominent longitudinal lobes, each with a secondary indentation, that are separated by furrows. Within the furrows are void spaces preserved as vugs with secondary botryoidal infillings. The specimens are also segmented transversely. This combination of 6-fold longitudinal lobes and furrows and transverse segmentation is consistent with the pattern formed by larval stages of many lepidopterids. This material demonstrates that both herbivore-plant and parasitic relationships similar to those today were already well established by the Neogene in northwestern North America.