New baculites from the Bearpaw shale and equivalent rocks of the Western Interior
W. A. Cobban
New species of baculites described from Montana include Baculites cuneatus and B. jenseni from the Bearpaw shale [Cretaceous] and B. rugosus from the Pierre Shale [Cretaceous]. Baculites compressus Say var. ornatus Robinson is renamed B. compressus Say Say subsp. robinsoni. These baculites have suture patterns similar to that of B. compressus Say in that the terminal branches of the first lateral lobe are constricted at their base. The sequence of baculites having this type of a suture are, from oldest to youngest, B. pseudovatus Elias, B. crickmayi Williams, B. rugosus n.sp., B. corrugatus Elias, B. compressus Say and B. compressus subsp. robinsoni, B. cuneatus n.sp., B. reesidei Elias, B. jenseni n.sp., and B. eliasi Cobban.
This record provided courtesy of AGI/GeoRef.
