Llandoverian thelodont scales from the Burnt Bluff Group of Wisconsin and Michigan

Phosphatic microfossils including copious microvertebrates and conodont ele ments indicative of the upper Icriodella discreta-Icriodella deflecta Zone (Aeronian) are found in a single bed of the Hendricks Formation, Burnt Bluf f Group, Sturgeon Bay, Wisconsin. Scales of thelodonts, including Loganelli a sp. cf. Loganellia siberica Karajute-Talimaa, 1978, and rare Valyalepis c rista Turner tin Turner and Nowlan, 1995) predominate among the microverteb rate remains. Most scales are referred to Zuegelepis potanus Turner new gen us and species. associated with the thelodont scales are rare phosphatic fr agments of questionable dermal "bone" and scales, possibly of heterostracan origin. Thelodont scales are also found in the Hendricks Formation at Faye tte State Park, Michigan and in the subsurface Byron Formation (Burnt Bluff Group) in Schoolcraft County, Michigan.