The Lakota Formation is a sequence of rocks of early Cretaceous (Berriasian to Barremian) age from Western North America. Located in South Dakota, the name of the formation is derived from the Lakota Native American tribe.
There are two units of the Lakota Formation, the Chilson Member (upper Berriasian to Valanginian) and the underlying Fuson Member (upper Valanginian to early Barremian). A Berriasian-Valanginian age for the Chilson Member has been extrapolated by means of ostracods and charophytes.
The Fuson Member takes its name from rock exposures in Fuson Canyon, a valley on the eastern side of the Black Hills.
Vertebrate paleofauna
Dinosaurs
Dinosaurs reported from the Lakota Formation Genus Species Location Stratigraphic position Material Notes ImagesDakotadonD. lakotaensisChilson Member"Skull, mandible, [and] vertebrae.""Table 19.1," in Weishampel, et al. (2004). Page 416.An ankylopollexian iguanodontHoplitosaurusH. marshiChilson Member"Partial postcranial skeleton [and] osteoderms.""Table 17.1," in Weishampel, et al. (2004). Page 366.An ankylosaur belonging to PolacanthidaeOsmakasaurusO. depressusChilson MemberPortions of both ilia, anterior part of the blade of one pubis, an incomplete sacrum, centrum of the last sacro-dorsal, 12 caudal vertebrae, 1 thoracic rib and many fragmentsAn ankylopollexian iguanodontMacronariaIndeterminateChilson MemberLeft humerus and right metacarpal IA macronarian related to CamarasaurusOrnithopodaIndeterminateLeft femurIndeterminate ornithopod, previously described as Hypsilophodon wielandi
Mammals
Mammals reported from the Lakota Formation Genus Species Location Stratigraphic position Material Notes ImagesBolodonB. hydeiChilson MemberRight M2A plagiaulacid multituberculateInfernolestesI. rougieriChilson MemberRight lower M1A spalacotheriid trechnotherian.LakotalestesL. luoiChilson MemberRight upper molar (M5?)A dryolestidPassumysP. angelliChilson MemberRight M1A plagiaulacid multituberculate
Turtles Turtles reported from the Lakota Formation Genus Species Location Stratigraphic position Material Notes ImagesLakotemysL. australodakotensisChilson MemberTwo shells and a partial skullA baenid paracryptodire
Other vertebrate remains found within the Lakota Formation include a fish scale from the gar Lepisosteus and a crocodile tooth
References