Description

Early Silurian (Llandoverian)

Brandon Bridge Formation

Waukesha, WI, USA

Extremely rare and unusual 2 inch animal on 5 inch slab.

Arthropod, Brandon Bridge Fauna.

The Brandon Bridge Fauna is one of the few Lagerstatten known between the Middle Cambrian Burgess Shale and the Early Devonian Hunsruckschiefer (Bundenbach, Germany).  There appears to be just one locality and it features a variety of trilobites, other arthropods, including perhaps the earliest-known horseshow crab relative, and a number of soft-bodied forms.  The fauna was reported over thirty years ago but a lot remains to be published on it.

See:

Donald G. Mikulic, Derek E. G. Briggs, Joanne Kluessendorf.  1985.

A Silurian Soft-Bodied Biota.  Science, New Series, Vol. 228, No. 4700 (May 10, 1985), pp. 715-717.  American Association for the Advancement of Science.