Abbreviated record for specimen 15637 Basic Information Determination: Alethopteris sullivanti Lesquereux Previously: none Type Status: Figured In: Langford, 1958, p. 241, fig. 441Wagner, 1968, p. 152 Locality: Will County, Illinois Geologic Unit: Francis Creek Shale Additional Information Images: medium (150 dpi, 119.9KB)large (600 dpi, image not available) Catalog Data: show full record