MARK A LOEWEN portrait
  • Associate Professor (Lecturer), Geology & Geophysics

Education

  • MSc, Paleontology, Loma Linda University. Project: Lateral salinity gradients in Eocene Fossil Lake, southwestern Wyoming
  • PhD, Geology, University of Utah. Project: Variation in the Late Jurassic theropod dinosaur Allosaurus: ontogenetic, functional and taxonomic implications

Research Summary

Mark Loewen is a vertebrate paleontologist at the University of Utah. He specializes in research on Jurassic and Cretaceous dinosaurs with an emphasis on the taxonomy, evolution and biogeography of meat eating, armored and horned dinosaurs. These include Allosaurus, Tyrannosaurus, Ankylosaurus and Triceratops. Along with colleagues he has named 13 dinosaurs including Lythronax, Kosmoceratops, Utahceratops and Seitaad.

Biography

                                                                       Research Papers

Loewen, M. A., and J. M. de Gibert Atienza. (In minor revision). A unique fish trail (Undichna) from the Eocene Green River Formation of Fossil Lake: paleoecological implications. PeerJ. 8:e7803 DOI 10.7717/peerj.7803

Loewen, M. A., M. J. Ryan, and D. C. Evans. (In minor revision). A new centrosaurine dinosaur (Ornithischia: Ceratopsidae) from the lower Judith River Formation (Campanian) of northcentral Montana. PLoS One.

Hendrickx, C., P. R. Bell, M. Pittman, A. R. C. Milner, E. Cuesta, J. O’Connor, M. A. Loewen, P. J. Currie, O. Mateus, T. G. Kaye and R. Delcourt. (In minor revision).  Morphology and distribution of scales, dermal ossifications, and other non-feather epidermal structures in non-avialan theropod dinosaurs. Biological Reviews.

Smith, E. A., and M. A. Loewen, and J. I. Kirkland. 2020. New social insect nests from the Upper Jurassic Morrison Formation of Utah. Geology of the Intermountain West. P234-261.

Chure, D. J., and M. A. Loewen, 2020. Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America. PeerJ.

Nesbitt, S. J., R. K. Denton, M. A. Loewen, S. L. Brusatte, N. D. Smith, A. H. Turner, J. I. Kirkland, A. T. McDonald and D. G. Wolfe. 2019. A mid-Cretaceous tyrannosauroid and the origin of North American end-Cretaceous dinosaur assemblages. Nature Ecology and Evolution 3:892–899.

Carrano, M. T., M. A. Loewen, and S. W. Evers. 2018. Comment on the proposed conservation of usage of Allosaurus Marsh, 1877 by designation of a neotype for its type species Allosaurus fragilis Marsh, 1877, (Case 3506; see BZN 67: 53–56, 178). Bulletin of Zoological Nomenclature.

Knapp, A., R. Knell, A. Farke, M. A. Loewen, D. Hone. 2018. Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution. Proceedings of the Royal Society B. 285:20180312. DOI: 10.1098/rspb.2018.0312

Chiba, K., M. J. Ryan, F. Fanti, M. A. Loewen, and D.C. Evans. 2017. New material and systematic re-evaluation of Medusaceratops lokii (Dinosauria: Ceratopsidae) from the Judith River Formation (Campanian, Montana). Journal of Paleontology. doi: 10.1017/jpa.2017.62

Ryan, M. J., R. Holmes, J. Mallon, M. A. Loewen, D. C. Evans. 2017. "A basal ceratopsid (Centrosaurinae: Nasutoceratopsini) from the Oldman Formation (Campanian) of Alberta, Canada". Canadian Journal of Earth Sciences. 54. doi:10.1139/cjes-2016-0110.

Tsolmon, A. C. L. Johnson, M. A. Loewen., K. A. Ritterbush, K. N. Constenius, C. M. Dinter. 2017. Microbial-caddisfly bioherm association from the Lower Cretaceous Shinekhudag Formation, Mongolia: Earliest record of plant armoring in fossil caddisfly cases. PLoS One. https://doi.org/10.1371/journal.pone.0188194

Lund, E. K., S. D. Sampson and M. A. Loewen. 2016. Nasutoceratops titusi (Ornithischia, Ceratopsidae), a basal centrosaurine ceratopsid from the Kaiparowits Formation, Southern Utah. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1071265.

Claessens L. P. A. M. and M. A. Loewen. 2015, A redescription of Ornithomimus velox Marsh 1890 (Dinosauria, Theropoda) Journal of Vertebrate Paleontology. DOI:10.1080/02724634.2015.1034593.

Ryan, M. J., D. C. Evans, P. J. Currie, and M. A. Loewen. 2014. A new chasmosaurine from northern Laramidia expands frill disparity in ceratopsid dinosaurs. Naturwissenschalften doi:10.1007/s00114-014-1183-1

DeBlieux, D. D., J. I. Kirkland, T. A. Gates, J. G. Eaton, M. A. Getty, S. D. Sampson, M. A. Loewen, and M. C. Hayden. 2013. Paleontological Overview and Taphonomy of the Middle Campanian Wahweap Formation in Grand Staircase-Escalante National Monument. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 563-587.

Evans, D. C., T. Williamson, M. J. Ryan, M. A. Loewen, and J. I. Kirkland. 2013. A review of pachycephalosaurian dinosaurs from Grand Staircase-Escalante National Monument, southern Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 482-487.

Kirkland, J. I., L. Alcalá, M. A. Loewen, E. Espílez, L. Mampel, J. P. Wiersma. 2013. The basal nodosaurid ankylosaur Europelta carbonensis n. gen., n. sp. from the Lower Cretaceous (lower Albian) Escucha Formation of northeastern Spain PLoS ONE 8(11): e79420. doi:10.1371/journal.pone.0080405

Loewen, M. A., R. B. Irmis, J. J. W. Sertich, P. J. Currie and S. D. Sampson. 2013. Tyrant dinosaur evolution tracks the rise and fall of Late Cretaceous oceans. PLoS ONE 8(11): e79420. doi:10.1371/journal.pone.0079420

Loewen, M. A. A. A. Farke, S. D. Sampson, M. A. Getty, E. K. Lund and P. M. O’Connor. 2013. Ceratopsid dinosaurs from the Grand Staircase of southern Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 488-503.

Loewen, M. A., M. E. Burns, M. A. Getty, J. I. Kirkland and M. K. Vickaryous. 2013. Review of Late Cretaceous ankylosaurian dinosaurs from the Grand Staircase region, southern Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 445-462.

Sampson, S. D., E. K. Lund, M. A. Loewen, A. A. Farke and K. E. Clayton. 2013. A remarkable short-snouted horned dinosaur from the Late Cretaceous (Campanian) of southern Utah. Proceedings of the Royal Society Biology 280:20131186. doi.org/10.1098/rspb.2013.1186

Sampson, S. D., M. A. Loewen, E. M. Roberts and M. A. Getty. 2013. A New Macrovertebrate Assemblage from the Late Cretaceous (Campanian) of Southern Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 599-622.

Thomson, T. J., R. B. Irmis and M. A. Loewen. 2013. First occurrence of a tyrannosaurid dinosaur from the Mesaverde Group (Neslen Formation) of Utah: Implications for upper Campanian Laramidian biogeography, Cretaceous Research 43:70-79.

Wiersma, J. P. and M. A. Loewen. 2013. Taphonomy of a subadult Teratophoneus curriei (Tyrannosauridae) from the Upper Campanian Kaiparowits Formation of Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 288-598.

Zanno, L. E, M. A. Loewen, A. A. Farke, G. Kim and L. P. A. M. Claessens and C. T. McGarrity. 2013. Late Cretaceous theropod dinosaurs of southern Utah. In A. L. Titus and M. A. Loewen, eds., At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 504-525.

Carrano, M. T., M. A. Loewen and J. J. W. Sertich. 2011. New materials of Masiakasaurus knopfleri Sampson, Carrano, and Forster, 2001 and implications for the morphology of the Noasauridae (Theropoda: Ceratosauria). Smithsonian Contributions to Paleobiology 95:1-53.

Farke, A. A., M. J. Ryan, P. M. Barrett, D. H. Tanke, D. R. Braman, M. A. Loewen, and M. R. Graham. 2011. A new centrosaurine from the Late Cretaceous of Alberta, Canada, and the evolution of parietal ornamentation in horned dinosaurs. Acta Palaeontologica Polonica. 56 (4):691-702. doi:10.4202/app.2010.0121.

Kirkland, J. I. and M. A. Loewen. 2011. Utah’s Prehistoric Tanks: the Ankylosaurs. Utah Geological Survey Notes. 43(3):4-5.

Gates, T. A., Sampson, S. D., L. E. Zanno, E. M. Roberts, J. G. Eaton, R. L Dydum, J. H. Hutchinson, J. A. Smith, M. A. Loewen, and M. A. Getty. 2010.  Biogeography of terrestrial and freshwater vertebrates from the late Cretaceous (Campanian) Western Interior of North America. Palaeogeography, Palaeoclimatology, Palaeoecology 291:371-387.

Getty, M. A., M. A. Loewen, E. M. Roberts, A. L. Titus and S. D. Sampson. 2010.  Taphonomy of horned dinosaurs (Ornithischia: Ceratopsidae) from the Late Campanian Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah, In: M. J. Ryan, B. J. Chinnery-Allgeier, and D. A. Eberth, eds., New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington: Indiana University Press. 478 – 494.

Loewen, M. A. and D. J. Chure. 2010. Comment on the proposed conservation of usage of Allosaurus Marsh, 1877 by designation of a neotype for its type species Allosaurus fragilis Marsh, 1877, (Case 3506; see BZN 67: 53–56, 178). Bulletin of Zoological Nomenclature 67(3).

Loewen, M. A., S. D. Sampson, E. K. Lund, A. A. Farke, C. de Leon, M. C. Aguillón Martínez, R. A. Rodríguez de la Rosa, M. A. Getty, and D. A. Eberth. 2010. Horned dinosaurs (Ornithischia: Ceratopsidae) from the Upper Cretaceous (Campanian) Cerro del Pueblo Formation, Coahuila, Mexico. In: M. J. Ryan, B. J. Chinnery-Allgeier, and D. A. Eberth, eds., New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington: Indiana University Press. 99 – 116.

Sampson, S. D. and M. A. Loewen. 2010.  Unraveling a radiation: a review of the diversity, stratigraphic distribution, biogeography, and evolution of horned dinosaurs (Ornithischia: Ceratopsidae), In: M. J. Ryan, B. J. Chinnery-Allgeier, and D. A. Eberth, eds., New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, Bloomington: Indiana University Press. 405 – 427.

Sampson, S. D., M. A. Loewen, A. A. Farke, E. M. Roberts, C. A. Forster, J. A. Smith, and A. L. Titus. 2010. New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. PLoS ONE 5(9):e12292.

Sertich, J. J. W., and M. A. Loewen. 2010. A New Basal Sauropodomorph Dinosaur from the Lower Jurassic Navajo Sandstone of Southern Utah. PLoS ONE, 5(3):e9789.

Sampson, S. D., T. A. Gates, E. M. Roberts, M. A. Getty, L. E. Zanno, A. L. Titus, M. A. Loewen, J. A. Smith, E. K. Lund and J. J. W. Sertich. 2010.  Grand Staircase-Escalante National Monument: A new and critical window into the world of dinosaurs. In: Learning from the Land, Grand Staircase-Escalante National Monument Science Symposium Proceedings, Grand Staircase-Escalante Partners. 141-158.

Zanno, L. E., J. P. Wiersma, M. A. Loewen, S. D. Sampson, and M. A. Getty. 2010.  A preliminary report on the theropod dinosaur fauna of the late Campanian Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah.  In: Learning from the Land, Grand Staircase-Escalante National Monument Science Symposium Proceedings, Grand Staircase-Escalante Partners. 173-186.

Farke, A. A., S. D. Sampson, C. A. Forster and M. A. Loewen. 2009. Turanoceratops tardabilis—sister taxon, but not a ceratopsid. Naturwissenchaften 96:869-870.

Leggitt, V. L. and M. A. Loewen. 2007. Immature aquatic dipteran impressions preserved in tufa: Eocene Fossil Lake, Wyoming, The Mountain Geologist, 44(2):1-7.

Leggitt, V. L., R. A. Cushman, M. A. Loewen and H. P. Buchheim. 2007. Caddisfly (Insecta: Trichoptera) cases used as unique autochthonous paleoenvironmental indicators: Eocene Lake Gosiute. The Mountain Geologist, 44(2):109-117.

Sampson, S. D. and M. A. Loewen. 2007.  New information on the diversity, stratigraphic distribution, biogeography, and evolution of ceratopsid dinosaurs.  Royal Tyrell Museum Ceratopsian Symposium Short Papers 125-133.

Getty, M. A., M. A. Loewen, A. L. Titus and S. D. Sampson. 2007.  Ceratopsid taphonomy from the Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah.  Royal Tyrell Museum Ceratopsian Symposium Short Papers 56-60.

Lund, E. K., M. A. Loewen, S. D. Sampson, M. A. Getty, M. C. Aguillón Martinez, R. A. Rodriguez de la Rosa and D. A. Eberth. 2007.  Ceratopsian remains from the Late Cretaceous Cerro del Pueblo Formation, Coahuila, Mexico.  Royal Tyrell Museum Ceratopsian Symposium Short Papers 108-113.

Sampson, S. D. and M. A. Loewen. 2005. Tyrannosaurus rex from the Upper Cretaceous (Maastrichtian) North Horn Formation of Utah: biogeographic and paleoecologic implications, Journal of Vertebrate Paleontology, 25(2):469-472.

Leggitt, V. L. and M. A. Loewen. 2002. Eocene Green River Formation “Oocardium tufa” reinterpreted as complex arrays of calcified caddisfly (Insecta: Trichoptera) larval cases, Sedimentary Geology, 148(1-2):139-146.

Buchheim, H. P., V. L. Leggitt, R. E. Biaggi, and M. A. Loewen. 1999. Paleoenvironments of avian trackway sites within the Olla Member, Palm Spring Formation, Anza-Borrego Desert State Park. Proceedings of the 1999 Desert Research Symposium, San Bernardino County Museum Association, 46(2):47-52.

Loewen, M. A., V. L. Leggitt and H. P. Buchheim. 1999. Caddisfly (Trichoptera) larval cases from Fossil Lake, Eocene Green River Formation, Fossil Butte National Monument, Wyoming, National Park Service Technical Report NPS/NRGRD/GRDTR-99/03:72-77.

Loewen, M. A., and H. P. Buchheim. 1998. Paleontology and paleoecology of the culminating phase of Eocene Fossil Lake, Fossil Butte National Monument, Wyoming, National Park Service Paleontological Research Volume 3:73-80

Edited Volume

Titus, A. L and M. A. Loewen, 2013. At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Bloomington: Indiana University Press. 621 pp.