In 1991, Robert S. Desowitz asked, “Did the primitive malaria begin as a parasite of some prehistoric reptile that later was picked up by a mosquito, or was it first a parasite of the mosquito that later became established in the reptile?” This question has been debated for years and is addressed in the present work in light of the fossil record of malarial organisms (Haemosporidia). The general consensus is that malaria evolved as a parasite of vertebrates ( Manwell 1961 , Desportes and Schrével 2013 , Mattingly 1983 ); however, Huff (1945) felt that the malaria progenitor originated with the vector, and in their discussion of malaria evolution, Di Fiore et al. (2009) recognized that in the digenetic malarial life cycle, the vector is the definitive host and the vertebrate the intermediate host. This question has also been addressed with molecular data, but...