Mayr, G., Alvarenga, H. and Mourer-Chauviré, C. (2011). "Out of Africa: Fossils shed light on the origin of the hoatzin, an iconic Neotropic bird." Naturwissenschaften, doi10.1007/s00114-011-0849-1
Gerald Mayr and Vanesa L. De Pietri (2014). «Earliest and first Northern Hemispheric hoatzin fossils substantiate Old World origin of a “Neotropic endemic”». Naturwissenschaften. in press. doi:10.1007/s00114-014-1144-8.