This image shows what appears to be a Pterinea brisa? pelecypod fossil. It was found in the Silurian age Waldron Shale layer of Clark County, Indiana, USA. It has not been prepped yet but has very distinctive lines outlining its growth pattern during the creatures short life.
Identification is based off of images from illustrations from Plate 28 (Figures 7-9) Indiana Department of Geology and Natural History Eleventh Annual Report John Collett State Geologist 1881. First image is Plate 28 Figure 7 and the second is Plate 28 Figure 9. Species name by Hall and referred to in his publications of 1867, 1870, and 1879.
