CONODONTS OF DISPARATE LOWER DEVONIAN ZONES, WILSON CREEK SHALE, TYERS-WALHALLA AREA, VICTORIA, AUSTRALIA

Thin limestone beds are a minor component of the Lower Devonian Wilson Creek Shale in the Tyers-Walhalla area of Victoria. Age-diagnostic co nodonts recovered are (1) Eognathodus sulcatus sulcatus, index to the sulcatus Zone (early Pragian), from the Thomson River south of Coopers Creek, and (2) Polygnathus dehiscens, index to the dehiscens Zone (ea rly Emsian), from Jacobs Creek. The Wilson Creek Shale thus ranges fro m the sulcatus Zone to the dehiscens Zone, and is partly equivalent to the Coopers Creek Limestone (sulcatus Zone). Low-oxygen deposition ex isted in central Victoria over a considerably longer period in the Ear ly Devonian than previously suspected.