Nothosaurus
| Nothosaurus | ||||||||||||
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Nothosaurus skeleton reconstruction in the Berlin Museum of Natural History |
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| Temporal occurrence | ||||||||||||
| Lower Triassic to Upper Triassic | ||||||||||||
| 251.2 to 228 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Nothosaurus | ||||||||||||
| Munster , 1834 | ||||||||||||
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Nothosaurus ( Greek for "false lizard" from νόθος nothos "false", as well as σαῦρος sauros "lizard") is an extinct medium-sized sauropterygian genus of the Triassic ( Olenekian to Carnian ) of Europe ( Netherlands , Germany , Poland , Italy , France , Switzerland , Spain , Bulgaria ) and Asia ( Israel , Saudi Arabia and China ).
features
According to Rieppel & Wild (1996), a diagnostic feature of the Nothosaurus genus is, among other things, the row of teeth in the upper jaw that extends far beyond the level of the front end of the upper temporal window (see below). The front part of the upper jaw (premaxillary) has relatively long teeth. At the transition to the main part of the upper jaw (maxillary) the snout, seen from above (dorsal), often shows a slight constriction, and the anterior maxillary teeth are relatively small. Due to the constriction, the front part of a Nothosaurus skull in the dorsal view is somewhat similar to that of a crocodile ( i.e. S.) , but in crocodiles the outer nostrils are unpaired and lie far in front on the snout, while in Nothosaurus they are paired and relatively close the eye openings. Another diagnostic feature is that in the anterior half of the maxillary there are two large “ fangs ”, one after the other, which are followed by a “ palisade ” of closely spaced, conical, but clearly smaller teeth.
The (postorbital) part of the skull located towards the tail of the eye openings is very long and makes up about half the length of the skull. The postorbital roof has two large upper temporal windows. Diagnostic for Nothosaurus is that the longitudinal axis of the temporal window is two to four times longer than that of the eye opening. There are no lower temporal windows - a characteristic of the Sauropterygians. The portion of the parietals on the upper (dorsal) roof of the skull is limited to the region near the central suture, and the pineal foramen, the opening for the pineal eye , is relatively large.
The cross-section of the upper arm bone (humerus) is more elongated than round. There are never more than three bones in the carpal and tarsus - another diagnostic feature.
The body length varies greatly within the genus and does not reach more than 7 meters in the largest species, with a skull length up to 60 centimeters. All Nothosaurus species differ from the contemporary and closely related Pachypleurosaurs in that they have a shorter tail but a longer neck in relation to the body.
Paleobiology
The Nothosaurus' way of life may have been similar to that of today's seals . It was probably more adapted to marine life than the pachypleurosaurs and - as a reptile - gave birth to its offspring living and in the water, an adaptation that has also been demonstrated in the ichthyosaurs . With regard to locomotion in water, it is assumed that propulsion was primarily generated paraxially, i.e. through the extremities, rather than by snaking movements in the longitudinal axis of the body. The flat skull offered little resistance to lateral movement under water.
Paleoecology
Nothosaurus was one of the top predators of its time and fed on fish, cephalopods , but also other reptiles. The arrangement of the teeth and the muscles of the jaw lead to the conclusion that they caught their prey like some crocodiles by holding the prey and then jerking their heads laterally. In the case of smaller prey, these are more likely to have been held in the tooth grid than to have been pierced with them.
Systematics and taxonomy
Internal systematics and taxonomic revisions since 2014
Since the work of Liu et al. (2014) the traditional system of Nothosaurus is changing. As a result of the cladistic analysis that was carried out in the context of that work, the genera Nothosaurus and Lariosaurus appear as non- monophyletic . Thus, among other things, some Nothosaurus species show a sister group relationship with individual Lariosaurus species. Already from the work by Rieppel et al. (2003) implicitly shows that there is a certain overlap of characteristics between traditional representatives of the genus Nothosaurus and Lariosaurus , even if in their analysis the genus Lariosaurus still turns out to be monophyletic. Ji et al. (2014), when discussing their finding of a specimen of “ Nothosaurus ” youngi, however, explicitly speak of a “ confusing mixture of features typical of Nothosaurus and Lariosaurus”. Consequently, " N. " youngi is one of the species that Liu et al. (2014) within the " Lariosaurus - clade " are.
Relationships of the Nothosauria according to Liu et al. (2014)
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The result of a subsequent analysis confirmed the contradiction to the conventional taxonomy of the Nothosaurids, whereupon the genus Lariosaurus was redefined and the species winkelhorsti , youngi and juvenilis were removed from the genus Nothosaurus and incorporated into the genus Lariosaurus . Lariosaurus is thus monophyletic again, but the genus Nothosaurus forms a paraphyletic series on the lineage of Lariosaurus . Since such paraphyletic groupings are not considered full-fledged taxa in modern systematics , because they do not go back to a recent common ancestor , further taxonomic modifications within the Nothosauridae would be necessary. These could either include the inclusion of the genus Lariosaurus (as a synonym or downgraded to the rank of a subgenus) in the then even more diverse genus Nothosaurus , or the creation of new genera or the "revival" of historical genera (see younger synonyms ) for all Nothosaurus species who do not have a recent common ancestor with the type species N. mirabilis . However, it has been pointed out that the non-monophyly of Nothosaurus in these relationship hypotheses could be due to an inadequate database, in which important comparative taxa such as Cymatosaurus and Pistosaurus are not represented.
Relationships of the Nothosauria according to Hinz et al. (2019)
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"Invalid" names
The following lists were taken from Rieppel & Wild (1996).
Noun Dubia
- Elmosaurus lelmensis Huene , 1957
- Hemilopas mentzeli Meyer , 1847
- Kolposaurus Dichthadius Skuphos , 1893
- Nothosaurus cuvieri Quenstedt , 1885
- Nothosaurus (Oligolycus) hecki Fritsch , 1894
- Nothosaurus mougeoti Meyer , 1842
- Nothosaurus picardi Chop , 1857
- Nothosaurus schimperi Meyer , 1847–1855
- Nothosaurus venustus Meyer , 1834
- Hemilopas Meyer , 1847
Nomina Nuda
Noun oblitum
- Conchiosaurus clavatus Meyer , 1834
Younger synonyms
- Synonyms of N. marchicus
- Synonyms of N. giganteus
- Synonyms of N. mirabilis
Geographical and stratigraphic distribution
The genus Nothosaurus is relatively widespread. In Germany it is documented with numerous copies. Important sites in Germany are Rüdersdorf near Berlin and Crailsheim . Other important sites are in Winterswijk in the Netherlands , in the Italian Eastern Alps and in Gogolin in Poland . Specimens of this genus have also been found in Machtesch Ramon ( Israel ) and the province of Tarragona in Spain . These two finds are considered evidence of the existence of the Burgundian Gate in the late Anisian and Ladinian , which connected the Central European Basin with the Tethys .
The geologically oldest occurrence of Nothosaurus - with material that cannot be determined at the species level - is in the Röt (youngest Olenekian ) of Rüdersdorf near Berlin in Brandenburg . The estheria layers (oldest carnium ) of Obersulm in Baden-Württemberg and the Bodenmühlwand near Bayreuth in Bavaria contain the most recent geological occurrence of Nothosaurus with N. edingerae .
literature
- Robert L. Carroll : Paleontology and Evolution of the Vertebrates. Thieme, Stuttgart a. a. 1993, ISBN 3-13-774401-6 .
Web links
Individual evidence
- ^ Georg zu Münster: Preliminary news about some new reptiles in the Muschelkalke of Baiern. In: New yearbook for mineralogy, geognosy, geology and petrefacts. Jhrg. 1834, No. 5, 1834, pp. 521-527, digitized .
- ↑ a b Olivier Rieppel, Hans Hagdorn : Fossil reptiles from the Spanish Muschelkalk (mont-ral and alcover, province Tarragona). In: Historical Biology. An International Journal of Paleobiology. Volume 13, No. 1, 1998, pp. 77-97, doi: 10.1080 / 08912969809386575 .
- ↑ a b c Olivier Rieppel, Jean-Michel Mazin, Eitan Tchernov: Speciation along rifting continental margins: a new Nothosaur from the Negev (Israël). In: Comptes Rendus de l'Académie des Sciences. Series IIA: Earth and Planetary Science. Volume 325, No. 12, 1997, pp. 991-997, doi: 10.1016 / S1251-8050 (97) 82380-4 .
- ↑ a b c † Nothosaurus Münster 1834. Paleobiology Database (accessed April 8, 2016).
- ↑ a b c d e f Olivier Rieppel , Rupert Wild : A revision of the genus Nothosaurus (Reptilia: Sauropterygia) from the Germanic Triassic, with comments on the status of Conchiosaurus clavatus (= Fieldiana. Geology. NS No. 34, ISSN 0096 -2651 = Field Museum of Natural History. Publication. 1479). Field Museum of Natural History, Chicago IL 1996, digitized .
- ↑ a b c Stefania Nosotti, Giorgio Teruzzi: I rettili di Besano-Monte San Giorgio (= Natura. Rivista di Scienze Naturali. Volume 98, No. 2, ISSN 0369-6243 ). Società Italiana di Scienze, Milan 2008.
- ↑ a b Jun Liu, Shi-xue Hu, Olivier Rieppel, Da-yong Jiang, Michael J. Benton, Neil P. Kelley, Jonathan C. Aitchison, Chang-yong Zhou, Wen Wen, Jin-yuan Huang, Tao Xie, Tao Lv: A gigantic nothosaur (Reptilia: Sauropterygia) from the Middle Triassic of SW China and its implication for the Triassic biotic recovery. In: Scientific Reports. Volume 4, 2014, Article No. 7142, doi: 10.1038 / srep07142 .
- ↑ Olivier Rieppel, Li Jinling, Liu Jun: Lariosaurus xingyiensis (Reptilia: Sauropterygia) from the Triassic of China. In: Canadian Journal of Earth Sciences. Volume 40, No. 4, 2003, pp. 621-634, doi: 10.1139 / e02-067 .
- ↑ Cheng Ji, Da-Yong Jiang, Olivier Rieppel, Ryosuke Motani, Andrea Tintori, Zuo-Yu Sun: A new specimen of Nothosaurus youngi from the Middle Triassic of Guizhou, China. In: Journal of Vertebrate Paleontology. Volume 34, No. 2, 2014, pp. 465-470, doi: 10.1080 / 02724634.2013.808204 .
- ↑ Wen-Bin Lin, Da-Yong Jiang, Olivier Rieppel, Ryosuke Motani, Cheng Ji, Andrea Tintori, Zuo-Yu Sun, Min Zhou: A new specimen of Lariosaurus xingyiensis (Reptilia, Sauropterygia) from the Ladinian (Middle Triassic) Zhuganpo Member, Falang Formation, Guizhou, China. In: Journal of Vertebrate Paleontology. Volume 37, No. 2, 2017, Item No. e1278703, doi: 10.1080 / 02724634.2017.1278703 .
- ↑ a b Juliane K. Hinz, Andreas T. Matzke, Hans-Ulrich Pfretzschner: A new nothosaur (Sauropterygia) from the Ladinian of Vellberg-Eschenau, southern Germany. In: Journal of Vertebrate Paleontology. 2019, item no. e1585364 (in press), doi: 10.1080 / 02724634.2019.1585364 .
- ^ Nicole Klein, Paul CH Albers: A new species of the sauropsid reptile Nothosaurus from the Lower Muschelkalk of the western Germanic Basin, Winterswijk, The Netherlands. In: Acta Palaeontologica Polonica. Volume 54, No. 4, 2009, pp. 589-598, doi: 10.4202 / app.2008.0083 .
- ↑ Alina Chrząstek, Robert Niedźwiedzki: Kręgowce retu i dolnego Wapienia muszlowego na Śląsku. In: Acta Universitatis Wratislaviensis. No. 2004 = Uniwersytet Wrocławski. Prace geologiczno-mineralogiczne. 64, 1998, ISSN 0525-4132 , pp. 69-81.
- ↑ Olivier Rieppel, Rupert Wild: Nothosaurus edingerae Schultze, 1970: Diagnosis of the Species and Comments on its Stratigraphical Occurrence (= Stuttgart contributions to natural history. Series B: Geologie und Paläontologie. 204, ISSN 0341-0153 ). State Museum for Natural History, Stuttgart 1994.