Janenschia Temporal range: 155–145 Ma Late Jurassic |
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Janenschia humerus, radius and ulna at the Museum für Naturkunde, Berlin | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Dinosauria |
Order: | Saurischia |
Suborder: | †Sauropodomorpha |
Clade: | †Neosauropoda |
Clade: | †Macronaria |
Clade: | †Camarasauromorpha |
Genus: |
†Janenschia Wild, 1991 |
Species: | †J. robusta |
Binomial name | |
Janenschia robusta Wild, 1991 |
Janenschia (named after Werner Janensch) was a large sauropod from Late Jurassic Tendaguru Formation of Tanzania, Africa (155 million years ago).
This sauropod has had a superfluous taxonomic and phylogenetic history. When first discovered, Eberhard Fraas named it as a species of Gigantosaurus, G. robustus, based on the holotype partial skeleton SMNS 12144. However, when Gigantosaurus was renamed Tornieria in 1911, G. robustus was placed in Tornieria, as T. robusta. Although Tornieria was eventually synonymized with Barosaurus (although nowadays considered distinct), SMNS 12144 was still referred to Tornieria by several authors, although one author referred T. robusta to Barosaurus, as B. robustus.
In 1991, German palaeontologist Rupert Wild of the Stuttgart Museum of Natural Sciences clarified the taxonomic status of G. robustus, by concluding that it was generically distinct from Tornieria. He renamed it Janenschia in honor of Werner Janensch, who had studied the vertebrate fauna from Tendaguru. Janenschia was placed in the family Titanosauridae, making it the oldest member of Titanosauria.
As a side note, a number of remains formerly assigned to Janenschia have been recognized as either distinct or belonging outside Neosauropoda. Two anterior dorsal vertebrae, and a possibly posterior cervical vertebra, previously referred to the genus were named Tendaguria in 2000. On the other hand, the caudal vertebral series MB.R.2091.1–30 does not overlap with SMNS 12144 and instead represents the first specimen of Mamenchisauridae from outside Asia. Recent cladistic analysis place Janenschia as a non-titanosauriform macronarian.
As a sauropod, it would have been a quadrupedal herbivore.