A new, giant ricinuleid (Arachnida, Ricinulei), from the Pennsylvanian of Illinois, and the identification of a new, ontogenetically stable, diagnostic character

Abstract

A new fossil ricinuleid, Curculioides bohemondi n. sp., from the Pennsylvanian Energy Shale of Illinois is described from a single specimen. It is the largest ricinuleid species yet described, living or extinct. The Energy Shale represents a new geographic locale for fossil ricinuleids, a sparsely distributed group. The species is distinguished from other members within the genus by the possession of very large (0.09 mm) carapace tubercles at a very low (30 mm-2) density. Statistical analyses are performed on extant and fossil ricinuleids to determine how their tubercles change throughout ontogeny, culminating in the recovery of a new ontogenetically stable diagnostic character: the tubercle coefficient (a measure of the size of the tubercles relative to body size). UUID: http://zoobank.org/aa9f2de5-c49d-4f70-bba5-db12fdee406f.

Systematics of the “Giant” Ricinulei (Ricinoididae: Ricinoides) of West Africa, with Descriptions of Five New Species and Comparative Morphology of the Male Copulatory Apparatus

“…305-319 Ma) of Europe and North America. The extinct ricinuleid fauna of this period was studied in detail by Selden (1992), and an additional new species was recently described (Whalen and Selden, 2020). Fossil ricinuleids from mid-Cretaceous (c. 99 Ma) Burmese amber deposits were described by Wunderlich (2012Wunderlich ( , 2015Wunderlich ( , 2017.…”