Janenschia

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Janenschia
Temporal range: 155–145  Ma
Janenschia.jpg
Janenschia humerus, radius and ulna at the Museum für Naturkunde, Berlin
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Neosauropoda
Clade: Macronaria
Genus: Janenschia
Wild, 1991
Species:
J. robusta
Binomial name
Janenschia robusta
(Fraas, 1908)

Janenschia (named after Werner Janensch) is a large herbivorous sauropod dinosaur from the Late Jurassic Tendaguru Formation of Lindi Region, Tanzania around 155 million years ago.

Alternate view Janenschia robusta.jpg
Alternate view

Discovery and naming

Janenschia has had a convoluted nomenclatural history. In 1907, Eberhard Fraas at "site P", nine hundred metres to the southeast of Tendaguru Hill, discovered two skeletons of gigantic sauropods. They were designated as "Skeleton A" and "Skeleton B". The fossils were transported to the collection of the Stuttgarter Naturaliensammlung in Stuttgart, Germany. Fraas in 1908 decided to name both skeletons as different species of one genus, Gigantosaurus. Skeleton A became Gigantosaurus africanus and skeleton B became Gigantosaurus robustus. The latter species was based on the holotype partial skeleton SMNS 12144, consisting of a right hindlimb. The specific name was inspired by the heavy build of the animal. [1] While doing so, Fraas knew full well that the name Gigantosaurus was already preoccupied by another taxon: Gigantosaurus megalonyx, named by Harry Govier Seeley in 1869. Fraas thought his actions could be justified by the fact that the description by Seeley had been limited and that the material of G. megalonyx had since been referred to another genus, Ornithopsis , by Richard Lydekker. [2] [3] [4] [5] [6]

In 1911, Richard Sternfeld renamed Gigantosaurus Fraas 1908 into Tornieria , pointing out that Fraas's arguments had been irrelevant. Tornieria africana became the type species of the new genus. [7] G. robustus was placed in Tornieria, as T. robusta. Sternfeld's move was not well received in Germany, as he had acted without consent of the ailing Fraas. In 1922, Werner Janensch, who at the Tendaguru had collected additional material, in an article describing the hand of the animal announced that he would keep using the name Gigantosaurus robustus. He claimed that G. megalonyx was a forgotten nomen oblitum and that the rules of the zoological nomenclature should be disregarded if they caused instability by replacing a well-known name by a completely new one. At the same time he synonymized Tornieria with Barosaurus as regarded its type species which then became a Barosaurus africanus. [8] Janensch, for the remainder of his career, would consistently apply the name Gigantosaurus robustus. In 1928, Sidney Henry Haughton exceptionally assigned Tornieria robusta to Barosaurus also, as a Barosaurus robustus. [9]

In 1930, Baron Franz Nopcsa rejected Janensch's arguments. He admitted that Sternfeld had been discourteous but pointed out that the ICZN only in 1927 recommended that the original author should be involved in such name changes. It would thus be absurd to object to an article written in 1911 — and in any case the lack of courtesy had no bearing on the validity of the name. Nopcsa had found several later mentions of G. megalonyx, which thus had not been a nomen oblitum. Furthermore, Gigantosaurus robustus had prior to 1922 not exactly been a well-known name itself. Distasteful as it might be, Nopcsa concluded, it was inevitable to consider Tornieria to be a valid name. [10] SMNS 12144 was subsequently referred to Tornieria by other authors. [11] [12] [13] [14]

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. [15]

A number of specimens formerly assigned to Janenschia have been recognized as distinct genera. Two anterior dorsal vertebrae, and a possible posterior cervical vertebra, previously referred to the genus, were named Tendaguria in 2000. [16] On the other hand, the caudal vertebral series MB.R.2091.1–30 does not overlap with SMNS 12144 and instead represents the first taxon of Mamenchisauridae from outside Asia, Wamweracaudia . [17] [18] Recent cladistic analysis places Janenschia as a non-titanosauriform sauropod. [19] [18]

Related Research Articles

Gigantosaurus is a dubious genus of sauropod dinosaur from the Late Jurassic Kimmeridge Clay Formation of England. The type species, Gigantosaurus megalonyx, was named and described by Harry Govier Seeley in 1869. Its syntype series consists of several separately discovered sauropod bones found in Cambridgeshire, including two caudal (tail) vertebrae, the distal end of a tibia, a cast of the right radius, a cast of phalanx and an osteoderm. It was synonymised to Ornithopsis humerocristatus by Richard Lydekker in 1888 and to Pelorosaurus by Friedrich von Huene in 1909. Today it is considered a nomen dubium.

<i>Kentrosaurus</i> Extinct genus of dinosaurs from late Jurassic in Lindi Region, Tanzania

Kentrosaurus is a genus of stegosaurid dinosaur from the Late Jurassic in Lindi Region of Tanzania. The type species is K. aethiopicus, named and described by German palaeontologist Edwin Hennig in 1915. Often thought to be a "primitive" member of the Stegosauria, several recent cladistic analyses find it as more derived than many other stegosaurs, and a close relative of Stegosaurus from the North American Morrison Formation within the Stegosauridae.

<i>Barosaurus</i> Diplodocid sauropod dinosaur genus from Upper Jurassic Period

Barosaurus was a giant, long-tailed, long-necked, plant-eating sauropod dinosaur closely related to the more familiar Diplodocus. Remains have been found in the Morrison Formation from the Upper Jurassic Period of Utah and South Dakota. It is present in stratigraphic zones 2–5.

<i>Procompsognathus</i> Extinct genus of dinosaurs

Procompsognathus is an extinct genus of coelophysid theropod dinosaur that lived approximately 210 million years ago during the later part of the Triassic Period, in what is now Germany. Procompsognathus was a small-sized, lightly built, ground-dwelling, bipedal carnivore, that could grow up to 1 m (3.3 ft) long.

<i>Giraffatitan</i> Sauropod dinosaur genus from the late Jurassic Period in Lindi Region, Tanzania

Giraffatitan is a genus of sauropod dinosaur that lived during the late Jurassic Period in what is now Lindi Region, Tanzania. It was originally named as an African species of Brachiosaurus (B. brancai), but this has since been moved to its own genus. Giraffatitan was for many decades known as the largest dinosaur but recent discoveries of several larger dinosaurs prove otherwise; giant titanosaurians appear to have surpassed Giraffatitan in terms of sheer mass. Also, the sauropod dinosaur Sauroposeidon is estimated to be taller and possibly heavier than Giraffatitan.

<i>Elaphrosaurus</i> Ceratosaurian theropod dinosaur genus from the Late Jurassic Period

Elaphrosaurus is a genus of ceratosaurian theropod dinosaur that lived approximately 154 to 150 million years ago during the Late Jurassic Period in what is now Tanzania in Africa. Elaphrosaurus was a medium-sized but lightly built member of the group that could grow up to 6.2 m (20 ft) long. Morphologically, this dinosaur is significant in two ways. Firstly, it has a relatively long body but is very shallow-chested for a theropod of its size. Secondly, it has very short hindlimbs in comparison with its body. Phylogenetic analyses indicate that this genus is likely a ceratosaur. Earlier suggestions that it is a late surviving coelophysoid have been examined but generally dismissed. Elaphrosaurus is currently believed to be a very close relative of Limusaurus, an unusual beaked ceratosaurian which may have been either herbivorous or omnivorous.

<i>Malawisaurus</i> Extinct genus of dinosaurs

Malawisaurus is an extinct genus of titanosaurian sauropod dinosaur. It is known from the Dinosaur Beds of northern Malawi, which probably date to the Aptian stage of the Early Cretaceous. The type species is M. dixeyi and the specific name honours Frederick Augustus Dixey.

<span class="mw-page-title-main">Lindi District, Lindi</span> District of Lindi Region, Tanzania

Lindi District also known as Mtama District is one of six administrative districts of Lindi Region in Tanzania. The District covers an area of 5,975 km2 (2,307 sq mi). Kilwa district is bordered to the north by Kilwa District, to the east by the Indian Ocean and Lindi Municipal District, to the south by the Mtwara Region, and to the west by the Nachingwea District. The district seat (capital) is the town and ward of Mtama. The district is known for the Tendaguru Formation, the richest Late Jurassic strata of fossils in Africa. According to the 2012 census, the district has a total population of 191,143.

<i>Bothriospondylus</i> Extinct genus of dinosaurs

Bothriospondylus is a dubious genus of neosauropod sauropod dinosaur. It lived during the Late Jurassic in England, and the type and only species is B. suffossus.

<i>Tornieria</i> Extinct genus of dinosaur

Tornieria is a genus of diplodocid sauropod dinosaur from the Late Jurassic in Lindi Region of Tanzania. It has a convoluted taxonomic history.

<i>Efraasia</i> Extinct genus of dinosaurs

Efraasia is a genus of basal sauropodomorph dinosaur. It was a herbivore which lived during the middle Norian stage of the Late Triassic, around 210 million years ago, in what is now Germany. It was named in 1973 after Eberhard Fraas, who during the early twentieth century collected what were the original type specimens.

<i>Tendaguria</i> Extinct genus of dinosaurs

Tendaguria is a genus of herbivorous sauropod dinosaur from the Late Jurassic of Lindi Region, Tanzania.

<span class="mw-page-title-main">Camarasauridae</span> Extinct family of dinosaurs

Camarasauridae is a family of sauropod dinosaurs. Among sauropods, camarasaurids are small to medium-sized, with relatively short necks. They are visually identifiable by a short skull with large nares, and broad, spatulate teeth filling a thick jaw. Based on cervical vertebrae and cervical rib biomechanics, camarasaurids most likely moved their necks in a vertical, rather than horizontal, sweeping motion, in contrast to most diplodocids.

<span class="mw-page-title-main">Tendaguru Formation</span> Geological formation and paleontological site in Tanzania

The Tendaguru Formation, or Tendaguru Beds are a highly fossiliferous formation and Lagerstätte located in the Lindi Region of southeastern Tanzania. The formation represents the oldest sedimentary unit of the Mandawa Basin, overlying Neoproterozoic basement, separating by a long hiatus and unconformity. The formation reaches a total sedimentary thickness of more than 110 metres (360 ft). The formation ranges in age from the late Middle Jurassic to the Early Cretaceous, Oxfordian to Hauterivian stages, with the base of the formation possibly extending into the Callovian.

<i>Australodocus</i> Extinct genus of dinosaurs

Australodocus is a genus of sauropod dinosaur that lived during the Late Jurassic period, around 150 million years ago, in what is now Lindi Region, Tanzania. Though initially considered a diplodocid, recent analyses suggest it may instead be a titanosauriform.

<i>Brachiosaurus</i> Sauropod dinosaur genus from the late Jurassic Period

Brachiosaurus is a genus of sauropod dinosaur that lived in North America during the Late Jurassic, about 154 to 150 million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Colorado River valley in western Colorado, United States. Riggs named the dinosaur Brachiosaurus altithorax; the generic name is Greek for "arm lizard", in reference to its proportionately long arms, and the specific name means "deep chest". Brachiosaurus is estimated to have been between 18 and 22 meters long; body mass estimates of the subadult holotype specimen range from 28.3 to 46.9 metric tons. It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in a steeply inclined trunk, and a proportionally shorter tail.

<i>Duriatitan</i> Extinct genus of dinosaurs

Duriatitan is a genus of titanosauriform sauropod dinosaur that lived in the Late Jurassic in what is now England. The holotype specimen of Duriatitan, BMNH 44635, is a partial left upper arm bone which was found by R.I. Smith near Sandsfoot in the lower Kimmeridge Clay from Dorset. The type species, D. humerocristatus, was described in 1874 by John Hulke as a species of Cetiosaurus and was noted as being similar to that of Gigantosaurus. The specific name refers to the deltopectoral crest, crista, on the upper arm bone, humerus. The specimen was assigned to its own genus by Paul M. Barrett, Roger B.J. Benson and Paul Upchurch in 2010. The generic name is derived from the Latin name for Dorset, Duria, and Greek Titan. Thomas Holtz estimated its length at 25 meters (82 ft).

<i>Ostafrikasaurus</i> Genus of theropod dinosaur

Ostafrikasaurus is a genus of theropod dinosaur from the Late Jurassic period of what is now Lindi Region, Tanzania. It is known only from fossil teeth discovered sometime between 1909 and 1912, during an expedition to the Tendaguru Formation by the Natural History Museum of Berlin. Eight teeth were originally attributed to the dubious dinosaur genus Labrosaurus, and later to Ceratosaurus, both known from the North American Morrison Formation. Subsequent studies attributed two of these teeth to a spinosaurid dinosaur, and in 2012, Ostafrikasaurus crassiserratus was named by French palaeontologist Eric Buffetaut, with one tooth as the holotype, and the other referred to the same species. The generic name comes from the German word for German East Africa, the former name of the colony in which the fossils were found, while the specific name comes from the Latin words for "thick" and "serrated", in reference to the form of the animal's teeth.

Wamweracaudia is a large herbivorous sauropod dinosaur from the Late Jurassic Tendaguru Formation of Tanzania, Africa, 155-145 million years ago.

References

  1. Fraas, E. (1908) "Dinosaurierfunde in Ostafrika", Jahreshefte des Vereins für Vaterländische Naturkunde in Württemberg 64: 84–86
  2. E. Fraas. 1908. "Ostafrikanische Dinosaurier". Mitteilungen aus dem Königlichen Naturalien-Kabinett zu Stuttgart55(61): 105-144
  3. E. Fraas. 1908. "Dinosaurier in Deutsch-Ostafrika". Die Umschau12(48): 943-948
  4. E. Fraas. 1911. "Die ostafrikanischen Dinosaurier". Verhandlungen der Gesellschaft Deutscher Naturfoscher und Ärzte83(1): 27-41
  5. E. Fraas. 1912. "Die ostafrikanischen Dinosaurier". Sammlung Wissenschaftlicher Vorträge1: 3-21
  6. Lydekker, R. 1888. Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. British Museum (Natural History), London, 309 pp
  7. R. Sternfeld. 1911. "Zur Nomenklatur der Gattung Gigantosaurus Fraas [On the nomenclature of the genus Gigantosaurus Fraas]". Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin8: 398
  8. Janensch, W., 1922, "Das Handskelett von Gigantosaurus robustus und Brachiosaurus brancai aus den Tendaguru-Schichten Deutsch-Ostafrikas", Centralblatt für Mineralogie, Geologie und Paläontologie1922: 464–480
  9. Haughton, S. H. (1928). "On some reptilian remains from the Dinosaur Beds of Nyasaland". Transactions of the Royal Society of South Africa. 16: 67–75. doi:10.1080/00359192809519658.
  10. Nopcsa, F. 1930. "Zur Systematik und Biologie der Sauropoden". Palaeobiologica, 3: 40-52
  11. Stromer, E. (1932). "Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltierreste der Baharîje-Stufe (unterstes Cenoman). 11. Sauropoda" [Results of the expeditions of Professor E. Stromer in the Egyptian deserts. II. Vertebrate animal remains from the Baharîje bed (lowest Cenomanian). 11. Sauropoda]. Abhandlungen der Bayerischen Akademie der Wissenschaften Mathematisch-naturwissenschaftliche Abteilung, Neue Folge 10:1–21
  12. Steel, R. (1970). Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Gustav Fischer Verlag, Stuttgart pp. 1–87
  13. Jain, S. L.; Kutty, T. S.; Roy-Chowdhury, T. K. and Chatterjee, S. (1979). "Some characteristics of Barapasaurus tagorei, a sauropod dinosaur from the Lower Jurassic of Deccan, India". In B. Laskar & C. S. Raja Rao (eds.), Fourth International Gondwana Symposium: Papers. Hindustan Publishing Corporation, Delhi 1:204–216
  14. Buffetaut, E. (1989). Une vertèbre de Dinosaure Titanosauridé dans le Cénomanien du Mans et ses implications paléobiogéographiques [A titanosaurid dinosaur vertebra in the Cenomanian of Le Mans and its paleobiogeographic implications]. Comptes Rendus de l'Académie des Sciences de Paris, Série II 309:437–443
  15. Wild, R. (1991). Janenschia n. g. robusta (E. Fraas 1908) pro Tornieria robusta (E. Fraas 1908) (Reptilia, Saurischia, Sauropodomorpha) [Janenschia n. g. robusta (E. Fraas 1908) for Tornieria robusta (E. Fraas 1908) (Reptilia, Saurischia, Sauropodomorpha)]. Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie) 173:1–4
  16. Bonaparte, J.F.; Heinrich, W.-D.; Wild, R. (2000). "Review of Janenschia Wild, with the description of a new sauropod from the Tendaguru beds of Tanzania and a discussion on the systematic value of procoelous caudal vertebrae in the Sauropoda". Palaeontographica Abteilung A. 256 (1–3): 25–76.
  17. Mannion, Philip D.; Upchurch, Paul; Barnes, Rosie N.; Mateus, Octávio (2013). "Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms" (PDF). Zoological Journal of the Linnean Society. 168: 98–206. doi:10.1111/zoj.12029.
  18. 1 2 Philip D Mannion, Paul Upchurch, Daniela Schwarz, Oliver Wings; Taxonomic affinities of the putative titanosaurs from the Late Jurassic Tendaguru Formation of Tanzania: phylogenetic and biogeographic implications for eusauropod dinosaur evolution, Zoological Journal of the Linnean Society, , zly068, https://doi.org/10.1093/zoolinnean/zly068
  19. Upchurch P.; Mannion P.D.; Taylor M.P. (2015). "The Anatomy and Phylogenetic Relationships of "Pelorosaurus" becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England". PLOS ONE. 10 (6): e0125819. Bibcode:2015PLoSO..1025819U. doi: 10.1371/journal.pone.0125819 . PMC   4454574 . PMID   26039587.