Larger image (17 kb)
Baculites was an uncoiled ammonite. Fragments of its shells, like this one, are very common in the Pierre Shale. Occasionally, a nearly complete shell is found. The various species are distinguished by their suture patterns, cross-sectional shapes, degree of taper, size, and surface ornament. The book by N. F. Larson et al., which is cited on the main Pierre Shale page, has a key for distinguishing between 24 species of Baculites found in the Pierre Shale. The suture pattern and relatively smooth body (i.e., the absence of lateral ribs) are distinguishing features of Baculites scotti. (Length 8 cm.)
For a closer look at the suture pattern, click here (42 kb).
A more complete specimen of a Baculites from the "Worldwide Museum of Natural History," still lacking part of the narrow end, can be seen here.
Back to Itano family home page
Back to Fossil home page