ACKNOWLEDGMENTS
We thank James L. Knight, former curator at the SC, for loan of the Crenatosiren specimen. Philippe Loubry (CNRS) is thanked for scanning the negatives of the photographs of the general views of MNHN.F.PPI 110. We thank Jorge Velez-Juarbe (Florida Museum of Natural History) and Brian Beatty (New York Institute of Technology) for their suggestions during the review process.