The type species is Bonatitan reigi, first described by Martinelli and Forasiepi in 2004. The specific epithet honours Osvaldo Reig. The holotype, MACN-PV RN 821, originally included a braincase and caudal vertebrae as well as limb elements. However, Salgado et al. (2014) emended the holotype to include the braincase only, and treated other elements catalogued under MACN-PV RN 821 as belonging to separate individual based on size and relative proportions.[3] The genus and species names honor the famous Argentine paleontologists José Fernando Bonaparte and Osvaldo Reig.
Phylogeny
Bonatitan in a cladogram after Navarro et al., 2022:[4]
^Martinelli, A. and Forasiepi, A.M. (2004). "Late Cretaceous vertebrates from Bajo de Santa Rosa (Allen Formation), Rio Negro province, Argentina, with the description of a new sauropod dinosaur (Titanosauridae)". Revista del Museo Argentino de Ciencias Naturales 6(2): 257–305.
^Salgado L., Gallina P.A. and Paulina Carabajal A. 2014. "Redescription of Bonatitan reigi (Sauropoda: Titanosauria), from the Campanian–Maastrichtian of the Río Negro Province (Argentina)". Historical Biology: An International Journal of Paleobiology 27(5): 525-548