Interests:
Quaternary vertebrate paleontology with emphasis on the paleoecology of Pleistocene and Holocene micromammals, zooarchaeology of archaeological sites on the northern Great Plains. 

Publications:

Semken Jr., H. A., H. G. McDonald, R. W. Graham, T. Adrain, J. A. Artz, R. G. Baker, A. B. Bryk, D. J. Brenzel, E. A. Bettis, A. A. Clack, B. L. Grimm, A. Haj, S. E. Horgen, M. C. Mahoney, H. A. Ray, and J. L. Theler. 2022. Paleobiology of Jefferson’s Ground Sloth (Megalonyx jeffersonii) derived from three contemporaneous, ontogenetically distinct, individuals recovered from Southwestern Iowa, U.S.A. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2022.2124115

Milideo, Lauren E., Russell W. Graham, Carl R. Falk, Holmes A. Semken Jr. and Max L. Christie. 2018.  Overprinting of taphonomic and paleoecological signals across the forest-prairie environmental gradient, mid-continent of North America. Paleobiology 44: 546-559. DOI: https://doi.org/10.1017/pab.2018.18.

Semken, Holmes A. Jr., and Carl R. Falk. 2014. Ecology and Environmental Degradation of Two Little Ice Age Earthlodge Villages in North Dakota: The Micromammal Evidence.  IN Archaeology, Zooarchaeology, and Malacology: A Festschrift for James L. Theler. (Matthew G. Hill, Ed.). The Wisconsin Archeologist: 95(2):249-264.

Fulton, Tara L. Ryan W. Norris, Russell W. Graham, Holmes A. Semken Jr. 2013.  Ancient DNA supports southern survival of Richardson's collared lemming (Dicrostonyx richardsoni) during the last glacial maximum. Molecular Ecology 22:  2540–2548. DOI: 10.1111/mec.12267

Semken, Holmes A., Jr., Russell W. Graham and Thomas W. Stafford, Jr. 2010.  AMS ¹⁴C analysis of Late Pleistocene non-analog faunal components from 21 cave deposits in southeastern North America. Quaternary International 217: 240-255. DOI: 10.1016/j.quaint.2009.11.031