The Late Jurassic Tendaguru Formation of Tanzania, southeastern Africa,
records a diverse and abundant sauropod fauna, including the
flagellicaudatan diplodocoids Dicraeosaurus and Tornieria, and the
brachiosaurid titanosauriform Giraffatitan. However, the taxonomic
affinities of other sympatric sauropod taxa and remains are poorly
understood. Here, we critically reassess and redescribe these problematic
taxa, and present the largest phylogenetic analysis for sauropods (117
taxa scored for 542 characters) to explore their placement within
Eusauropoda. A full re-description of the holotype of Janenschia, and all
referable remains, supports its validity and placement as a nonneosauropod
eusauropod. New information on the internal pneumatic
tissue structure of the anterior dorsal vertebrae of the enigmatic
Tendaguria tanzaniensis, coupled with a full re-description, results in its
novel placement as a turiasaur. A previously referred caudal sequence
cannot be assigned to Janenschia and displays several features that
indicate a close relationship with Middle–Late Jurassic East Asian
mamenchisaurids. It can be diagnosed by six autapomorphies, and we
erect the new taxon Wamweracaudia keranjei n. gen. n. sp. The Tendaguru
Formation shares representatives of nearly all sauropod lineages with
Middle Jurassic–earliest Cretaceous global faunas, but displays a greater
range of diversity than any of those faunas considered individually.