Agathaeromys donovani is known from four fossil sites—Fontein, Porto Spanjo, Barcadera-Karpata, and "80 m above sea level"—that have yielded 259, 148, 54, and 5 molars, respectively. Agathaeromys praeuniversitatis is known from 35 molars from a single site (Seroe Grandi). Although the deposits have not been precisely dated, Zijlstra and colleagues suggested on the basis of correlations with similar deposits on nearby Curaçao and sea-level fluctuations that the material of A. praeuniversitatis is likely 540,000 to 230,000 years old and that of A. donovani is likely 900,000 to 540,000 years old.Zijlstra et al., 2010, p. 869 Similarly aged fossil sites are also known from the nearby islands of Curaçao and Aruba, but these contain various other rodents, including Megalomys curazensis and Dushimys larsi on Curaçao and species of Oligoryzomys, Sigmodon, and Zygodontomys on Aruba.Zijlstra et al., 2010, p. 872; Zijlstra, 2012, p. 67 Agathaeromys probably descends from an unknown oryzomyine that migrated to the island from mainland Venezuela sometime during the Pleistocene.Zijlstra et al., 2010, p. 872
