caa a22 4500 388017864 CHVBK 20180307124916.0 cr unu---uuuuu 161130e199805 xx s 000 0 eng 10.1017/S0022336000024227 doi S0022336000024227 pii (NATIONALLICENCE)cambridge-10.1017/S0022336000024227 New findings of the ammonite Rhaeboceras, including a new species, from the Pierre Shale of eastern Montana [Elektronische Daten] [Joyce C. Grier, James W. Grier] A third known specimen of the ammonite Rhaeboceras burkholderi Cobban, 1987, has been discovered in the upper part of the Pierre Shale of early Maastrichtian age (Late Cretaceous) Baculites eliasi zone of Dawson County, Montana. This finding extends both the geographical and stratigraphic ranges of the species. In addition, R. cedarense new species is described from the Baculites baculus/grandis zone of the same region, which extends the stratigraphic range of the genus as currently recognized. The new species is a small form of Rhaeboceras that appears to be closely related to and probably descended from R. burkholderi. Copyright © The Paleontological Society Grier Joyce C. Department of Geosciences and Department of Zoology, North Dakota State University, Fargo 58105-5517 <grier@prairie.nodak.edu> aut Grier James W. Department of Geosciences and Department of Zoology, North Dakota State University, Fargo 58105-5517 <grier@prairie.nodak.edu> aut Journal of Paleontology Cambridge University Press 72/3(1998-05), 473-476 0022-3360 72:3<473 1998 72 JPA https://doi.org/10.1017/S0022336000024227 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0022336000024227 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Grier Joyce C. Department of Geosciences and Department of Zoology, North Dakota State University, Fargo 58105-5517 <grier@prairie.nodak.edu> aut NATIONALLICENCE 700 1- Grier James W. Department of Geosciences and Department of Zoology, North Dakota State University, Fargo 58105-5517 <grier@prairie.nodak.edu> aut NATIONALLICENCE 773 0- Journal of Paleontology Cambridge University Press 72/3(1998-05), 473-476 0022-3360 72:3<473 1998 72 JPA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge