Procyonids are well known biologically but knowledge of their fossil record is comparatively sparse. This study seeks to describe a sample of late Blancan procyonid fossils composed mostly of postcranial and dental material. Fossils are analyzed using linear and 2D geometric morphometrics and compared with a large sample of modern specimens from a wide geographic area to understand the range of intraspecific variation. The large Procyon species is described as a new taxon based on morphology of the postcrania and lower dentition, while another Procyon species is also described as new due to an apomorphy in the upper dentition. A new species of coati (genus Nasua) is identified and described based on lower dentition and postcranial morphology. The Blancan species P. rexroadensis is synonymized with P. lotor because the distinguishing dental feature for which the species is named is within the range of variation for P. lotor.

Two peccary species, Mylohyus elmorei and Prosthennops serus are described from the medium-bodied fauna of the Gray Fossil Site (GFS) of northeastern Tennessee. This site, recognized as an oak-hickory forest, is latest Hemphillian or earliest Blancan based on mammalian biochronology, with an estimated age of 4.9-4.5 Ma. The GFS represents the only site outside the Palmetto Fauna of Florida with M. elmorei, greatly expanding the species range north over 920 km, well into the Appalachian region. This is also the first Appalachian occurrence of the relatively widespread P. serus. Our understanding of intraspecific variation for both M. elmorei and P. serus is expanded due to morphological and proportional differences found in cranial and dental material from the GFS, Tyner Farm locality, Palmetto Fauna, and within the literature. The GFS M. elmorei material represents the most complete mandible and second cranium for the species, and preserve intraspecific variation in the length of the diastema, dental proportions, and the complexity of the cuspules of the hypoconulid complex. Similarly, mandibular material from the GFS for P. serus exhibited larger dentitions and a greater degree of robustness than currently recognized for the species.

The fossiliferous sediments of the Hueso and Tapiado formations exposed in the Vallecito Creek-Fish Creek section (VCFC) of the Anza-Borrego Desert (ABD) span the boundary between Blancan and Irvingtonian North American Land Mammal 'Ages.' Historically, the determination of the Blancan-Irvingtonian (B-I) boundary in the VCFC proved problematic. A new study to determine the B-I boundary in the VCFC revealed data inaccuracies in both published works and curatorial records of the mammal and other vertebrate fossils from the ABD. Most individual inaccuracies were minor, but an accumulation of over 50 years of multiple inaccuracies had significant effects on local and regional biostratigraphic and biochronologic correlations. A detailed investigation of the inaccurate data resulted in recognition of 17 types of error, with at least five sources. The two most prominent sources of error are those derived from publication and curation protocols. Examination of over 150 publications and in-house faunal lists produced over 830 taxonomic names and format variants, for 110 mammalian taxa identified from the ABD and VCFC. Approximately 50% of the taxonomic identifications were previously published without voucher catalogue numbers or fossil descriptions. A critical review of the taxonomic assignments resulted in an updated faunal list of ABD terrestrial Mammalia, including 110 taxonomic names, 66 unqualified genera, and 46 unqualified species. A supplemental list of 'retired' taxa includes 178 previously published or listed taxonomic names and format variants. The 4.5 km sequence of originally superposed sediments within VCFC is now tilted at 23 degrees and exposed in plan view. This exposure was captured in both aerial photos and satellite imagery. GIS layers of the Geomagnetic Polarity Time Scale and individual collecting localities are readily superposed onto the stratigraphic images. When united with the faunal database, GIS maps of biostratigraphic data facilitate detection and correction of data errors. Resulting corrected maps show highest and lowest stratigraphic occurrences of taxa, as well as geographic clustering of taxonomic groups, outlining possible paleohabitats. As a result of data improvement and GIS display, the local B-I boundary currently is best estimated by the presence of Ovibovini at >1.42 Ma. / text