Supplemental datasets for the publication: Pyenson et al. (2015), Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of 'river dolphins' in the Americas. PeerJ 3:e1227; DOI 10.7717/peerj.1227 The datasets included in this Zenodo archive include primarily raw CT scan data (DICOM files) and derived 3D models (OBJ and STL files) for the three major osteological elements of the type specimen (USNM 546125) of Isthminia panamensis: the skull; the mandible (i.e., right and left jaws); and the right scapula. Only DICOM data are available for the scapula at the current time. Eventually, all of the CT data and 3D models will be deposited into a Smithsonian digital repository. All of the 3D models are also available at the Smithsonian X 3D website (http://3d.si.edu), where users can visualize, measure, manipulate them, and, subsequent to login, can download 3D files for printing. The files in this archive include materials published with the original article in PeerJ (Pyenson et al., 2015). The type specimen itself (USNM 546125) is housed in the Department of Paleobiology at the Smithsonian Institution's National Museum of Natural History in Washington, D.C.