{"pk":41714,"title":"Epiplastral and geographic variation in \nEchmatemys\n, a geoemydid turtle from the Eocene of North America: A multi-tiered analysis of epiplastral shape complexity","subtitle":null,"abstract":"Numerous geoemydid turtle fossils from the extinct genus \nEchmatemys\n have been recovered from the middle Eocene Uinta Formation, Uinta Basin, Utah over the past several decades. Here, we tested whether co-occurring Uintan species \nEchmatemys callopyge\n and \nE. uintensis\n can be reliably differentiated based on epiplastral morphology, and whether their geospatial distributions overlapped significantly. The geographic spatial and stratigraphic distributions of Uinta Basin \nE. callopyge\n and \nE. uintensis\n specimens were compared using ArcGIS and analysis of variance (ANOVA). The analysis revealed overlapping geographic distributions of these two species, and no significant differences in stratigraphic dispersal. This finding of extensive geospatial overlap between the two Uintan \nEchmatemys\n species highlights the need for accurate taxonomic identification, such as the gular scale morphology validated here. In addition, we sought to address a methodological question regarding the relative efficacy of data complexity in this context. Using epiplastra from three additional Eocene species of \nEchmatemys\n, we employed hierarchical analyses of increasing data complexity, from standard linear dimensions to 2D geometric morphometrics to 3D laser scans, to determine the degree to which data complexity contributes to taxonomic assessments within this genus. Uintan species \nE. callopyge\n and \nE. uintensis\n were found to differ significantly in epiplastral shape as captured by all three categories of data. These findings verify that these two co-occurring species can be differentiated consistently using the shape of the gular scale, and that the use of geometric morphometrics can improve identification of fragmentary specimens. Among the non-Uintan species, dorsal and ventral 2D landmark data reliably differentiated among species, but the linear dimensions were less useful.","language":"en","license":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0","short_name":"CC BY-NC-SA 4.0","text":"<p><!-- x-tinymce/html --></p>\n<p>Readers are free to:</p>\n<ul>\n<li><strong>Share</strong> — copy and redistribute the material in any medium or format</li>\n<li><strong>Adapt</strong> — remix, transform, and build upon the material<br><br>The licensor cannot revoke these freedoms as long as you follow the license terms.</li>\n</ul>\n<p>Under the following terms:</p>\n<ul>\n<li><strong>Attribution</strong> — You must give appropriate credit , provide a link to the license, and indicate if changes were made . You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.</li>\n<li><strong>NonCommercial</strong> — You may not use the material for commercial purposes .</li>\n<li><strong>ShareAlike</strong> — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.<br><br>No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.</li>\n</ul>\n<p>Notices:</p>\n<p>You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation.</p>\n<p>No warranties are given. The license may not give you all of the permissions necessary for your intended use. For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.</p>","url":"https://creativecommons.org/licenses/by-nc-sa/4.0"},"keywords":[{"word":"ArcGIS, geometric morphometrics, Uintan NALMA, turtle evolution, Geoemydidae"}],"section":"Article","is_remote":true,"remote_url":"https://escholarship.org/uc/item/9cn4w7n6","frozenauthors":[{"first_name":"Heather","middle_name":"F.","last_name":"Smith","name_suffix":"","institution":"Department of Anatomy, Midwestern University, 19555 N. 59th Avenue, Glendale, Arizona 85308, USA; School of Human Evolution and Social Change, Arizona State University, P.O. Box 2402, Tempe, Arizona 85287, USA.","department":"None"},{"first_name":"Daniel","middle_name":"","last_name":"Jager","name_suffix":"","institution":"Department of Anatomy, Midwestern University, 19555 N. 59th Avenue, Glendale, Arizona 85308, USA","department":"None"},{"first_name":"J.","middle_name":"Howard","last_name":"Hutchison","name_suffix":"","institution":"University of California Museum of Paleontology, University of California Berkeley, 1101 Valley Life Sciences Building, Berkeley, California 94720, USA","department":"None"},{"first_name":"Brent","middle_name":"","last_name":"Adrian","name_suffix":"","institution":"Department of Anatomy, Midwestern University, 19555 N. 59th Avenue, Glendale, Arizona 85308, USA","department":"None"},{"first_name":"K.E.","middle_name":"Beth","last_name":"Townsend","name_suffix":"","institution":"Department of Anatomy, Midwestern University, 19555 N. 59th Avenue, Glendale, Arizona 85308, USA","department":"None"}],"date_submitted":"2020-02-05T12:40:29-08:00","date_accepted":"2020-02-05T12:40:29-08:00","date_published":"2020-02-05T00:00:00-08:00","render_galley":null,"galleys":[{"label":"","type":"pdf","path":"https://journalpub.escholarship.org/ucmp_paleobios/article/41714/galley/31205/download/"}]}