Waukesha Biota

The discovery of the Waukesha Biota was first published in 1985 by paleontologists D. G. Mikulic, D. E. G. Briggs, and Joanne Kluessendorf. The exceptional preservation of the fossils of the Waukesha Biota thus provides a window to a significant portion of Silurian life that otherwise may have been undetected and therefore unknown to science. == Stratigraphy and depositional environment ==

Most of the Waukesha Biota is preserved within a layer of thinly-laminated, fine-grained, shallow marine sediments of the Brandon Bridge Formation consisting of mudstone and dolomite deposited in a sedimentary trap at the end of an erosional scarp over the eroded dolomites of the Schoolcraft and Burnt Bluff Formations. A separate thin bed containing the biota is also present about above the interval. Fossils of unambiguous, fully terrestrial organisms are lacking from the Waukesha Biota. Most of the Waukesha Biota fossils were found at a quarry in Waukesha County, Wisconsin, owned and operated by the Waukesha Lime and Stone Company. Other fossils were collected from a quarry in Franklin, Milwaukee County, owned and operated by Franklin Aggregate Inc. That quarry lies south of the quarry in Waukesha. The Franklin fossils were from blasted material apparently originating from a horizon and setting equivalent to that of the Waukesha site. Its biota is similar to that from the Waukesha site, except that it lacks trilobites. == Taphonomy ==

Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The taphonomy of the Waukesha Biota is unusual in preserving few of the kinds of animals that typically dominate the Silurian fossil record, including in other strata of the same two quarries. Fossils of corals, echinoderms, brachiopods, bryozoans, gastropods, bivalves, and cephalopods are rare or absent from the Waukesha Biota, although trilobites are diverse and common. == Biota ==

Alga One genus of dasycladalean alga is known from the lagerstätte. Hemichordata Many of the hemichordates are members of the group Graptolithina. Porifera Poriferans, also known as sea sponges, are rare in this locality, with only one specimen known. Cnidaria The cnidarians of the site are mainly represented by conulariids, but coral are also known. "Worms" Multiple soft bodied fossils of "worms" and other vermiform animals are known from the site. Arthropoda Arthropods dominate the fauna of the Waukesha biota in both number of specimens and diversity. A wide variety including crustaceans, trilobites, chelicerates, and less familiar groups like the thylacocephalans and cheloniellids are known. Also found are enigmatic arthropods whose taxonomy has puzzled paleontologists since the sites discovery. Chordata Multiple chordate fossils (possibly belonging to conodonts) are known from this site. == See also ==