Janenschia ‭(‬named after Werner Janensch‭)‬

Short Info

Janenschia ‭(‬named after Werner Janensch‭)‬

Phonetic : Ya-nen-she-a.

Named By : Rupert Wild‭ ‬-‭ ‬1991

Diet : Herbivore

Size : Estimated 20 meters long

Type of Dinosaur : Sauropod

Type Species : J.‭ ‬robusta‭ (‬type‭)‬

Found in : Tanzania‭ ‬-‭ ‬Tendaguru Formation

When it Lived : Late Jurassic, 154-151 million years ago

Janenschia, named after Werner Janensch, is a large herbivorous dinosaur that lived in Tanzania, Africa, 155 millions years ago.

Janenschia’s nomenclatural history is complicated. Eberhard Fraas, nine hundred meters to the southeast Tendaguru Hill’s northeast, found two skeletons of huge sauropods in “site P” in 1907. They were named “Skeleton A”, and “Skeleton A”. They were taken to Stuttgarter Naturaliensammlung, Germany. Fraas decided in 1908 to name the skeletons two different species of Gigantosaurus, a genus that he had created. Skeleton A was named Gigantosaurus africanus, and skeletonB became Gigantosaurus strongus. This species was created from the partial holotype skeleton (SMNS 12144), which included a right hindlimb. Due to the animal’s heavy build, the specific name was chosen. Fraas was aware that Gigantosaurus had been named in 1869 by Harry Govier Seeley. Fraas believed his actions were justified by Seeley’s limited description and Richard Lydekker’s reference to G. megalonyx as an Ornithopsis genus.

Richard Sternfeld changed the name of Gigantosaurus Fraas 1908 to Tornieria in 1911. Sternfeld pointed out that Fraas’s arguments were irrelevant. Tornieria Africana was chosen as the type species for the new genus. G. robustus was added to Tornieria as T. robusta. Sternfeld’s decision was not received well in Germany because he had done so without the consent of the frail Fraas. Werner Janensch, a Tendaguru researcher, published an article about the hand of the animal in 1922. He stated that he would continue to use the name Gigantosaurus strongus. G. megalonyx, he claimed, was a forgotten nomen-oblitum. He also stated that the rules of zoological nomenclature should not be ignored if they cause instability by replacing an established name with a completely different one. He also synonymized Tornieria and Barosaurus to refer to its type species, which became a Barosaurus africanus. Janensch would continue to use the name Gigantosaurus strongus throughout his career. Sidney Henry Haughton in 1928 attributed Tornieria robusta as a Barosaurus strongus.

In 1930, Baron Franz Nopcsa rejected Janensch’s arguments. Sternfeld admitted that he had been rude, but he pointed out that the ICZN in 1927 only recommended that the original author be involved in name changes. Therefore, it would be absurd to object an article written in 1911. In any event, the lack of courtesy did not affect the validity of the name. Nopcsa had discovered several references to G. megalonyx in later years, so it was not a nomen obsidianum. Gigantosaurus robustus was not a well-known name prior to 1922. Although it may seem distasteful, Nopcsa decided that Tornieria was a valid name. Other authors referred to SMNS 12144 as Tornieria.

Rupert Wild, a German Palaeontologist, clarified the taxonomic status of G. robustus in 1991. He concluded that it was generically different from Tornieria. Janenschia was renamed in his honor after Werner Janensch who had studied Tendaguru’s vertebrate fauna. Janenschia was added to the Titanosauridae family, making it the oldest member Titanosauria.

Numerous specimens that were previously assigned to Janenschia are now recognized as distinct genera. Tendaguria was established in 2000. It included two anterior dorsal vertebrae and one possible posterior cervical vertebra. The caudal series MB.R.2091.1-30, on the other hand, does not overlap with SMNS12144, and instead represents Wamweracaudia, the first taxon in Mamenchisauridae outside of Asia. Recent cladistic analysis has identified Janenschia to be a non-titanosauriform Sauropod.

Source: Wikipedia