B. baileyi is known from the holotype left metatarsal, UNSM 50665, which was collected in the Maastrichtian-age Hell Creek FormationofSouth Dakota, United States (dated to between 66.8 and 66 Ma ago[1])
B. mongoliensis is known from the holotype left metatarsal, PIN 4491-8, which was collected in the Maastrichtian-age Nemegt FormationofMongolia.
B. varneri was originally named as a second species of Baptornis by James Martin and Amanda Cordes-Person in 2007. It is based on the holotype left tarsometatarsal SDSM 68430 which was collected in the Campanian-age Sharon Springs Formation, lower Pierre Shale of southwestern South Dakota (dated to between 81.5 and 80.5 million years ago.[2]). "Baptornis" varneri might represent a fourth species of Brodavis or belong to a separate genus.
Brodavis is considered to be the first freshwater and latest record of the order Hesperornithiformes. Although hesperornithiforms probably lost their flight abilities by the end of the Early Cretaceous, minimal pachyostosisinBrodavis suggests the possibility of some volant abilities.[3]
^Longrich, N.R., Tokaryk, T. and Field, D.J. (2011).『Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary.』Proceedings of the National Academy of Sciences, 108(37): 15253-15257. doi:10.1073/pnas.1110395108
^Carpenter, K. (2003). "Vertebrate Biostratigraphy of the Smoky Hill Chalk (Niobrara Formation) and the Sharon Springs Member (Pierre Shale)." High-Resolution Approaches in Stratigraphic Paleontology, 21: 421-437. doi:10.1007/978-1-4020-9053-0
^Larry D. Martin, Evgeny N. Kurochkin and Tim T. Tokaryk (2012). "A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia". Palaeoworld. 21: 59–63. doi:10.1016/j.palwor.2012.02.005.
