Mata Amarilla Formation
| Mata Amarilla Formation | ||
|---|---|---|
Ma | ||
Approximate paleocoordinates 56°30′S 48°48′W / 56.5°S 48.8°W | | |
| Region | Santa Cruz Province | |
| Country | Argentina | |
| Extent | Austral Basin | |
  Mata Amarilla Formation (Argentina) | ||
The Mata Amarilla Formation is a
The Mata Amarilla Formation has provided many fossil vertebrates, among which dinosaurs, fish and turtles, as well as fossil insects, flora and molluscs.
Age
The middle section of the Mata Amarilla Formation has widely been regarded as Maastrichtian in age, but recent dating of a lava tuff layer shows that it dates back to 96.2 ± 0.7 Ma, during the Cenomanian.[1]
Description
The Austral (or Magallanes) Basin, is located on the southwestern end of the South American Plate and it is bordered to the south by the Scotia Plate covering an area of approximately 230.000 square kilometres (88.803 sq mi). In the studied area, the Austral Basin underwent three main tectonic stages: (i) a rift stage; (ii) a thermal subsidence stage; and (iii) a foreland stage.
The rifting stage is related to the break-up of Gondwana, grabens and half-grabens were formed and filled with volcaniclastic and volcanic rocks intercalated with epiclastic sediments of the El Quemado and Tobífera Formations.[2]
Subsequently, the
The foreland stage, in response to the regional change from extensive to compressive regime, resulted in the deposition of the continental Mata Amarilla Formation. This unit is mainly composed of grey and blackish
The middle section comprises
Paleosol features and paleosol-derived climatic proxies suggest a subtropical temperate-warm, at 12 ± 2.1 °C (53.6 ± 3.8 °F) and humid, with 1,404 ± 108 millimetres (55.3 ± 4.3 in)/yr, climate with marked rainfall seasonality during the deposition of this unit (Varela et al. 2012b; 2018), in accordance with previous paleobotanical interpretations.[3]
Fossil content
Dinosaurs
| Dinosaurs | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Clasmodosaurus | C. spatula | Middle Section | ||||
| Loncosaurus | L. argentinus | Middle Section | ||||
Other vertebrates
- Ceratodus iheringi
- Lepidotes sp.
- Chelidae indet.
- Elasmosauridae indet.
- ?Docodonta indet.[4]
- Ausktribosphenidae indet.[4]
- Amarillodon meridionalis[4]
- Treslagosodon shehuensis[4]
Molluscs
- Glyphea oculata
- Anagaudryceras cf. politissimum
- Baculites cf. kirki
- Polyptychoceras (Polyptychoceras) sp.
- cf. Potamides sp.
Insects
Flora
References
- ^ Varela et al., 2012
- ^ Santamarina et al., 2018, p.608
- ^ Santamarina et al., 2018, p.609
- ^ S2CID 245549530.
- ^ Cerro Waring at Fossilworks.org
- ^ Santamarina et al., 2018, p.610
Bibliography
- Santamarina, Patricio E.; Viviana D. Barreda; Ari Iglesias, and Augusto N. Varela. 2018. Salvinialean megaspores in the Late Cretaceous of southern Patagonia, Argentina. Acta Palaeontologica Polonica 63. 607-616. Accessed 2019-10-13.
Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. - Rauhut, O.W.M. 2012. A reappraisal of a putative record of abelisauroid theropod dinosaur from the Middle Jurassic of England. Proceedings of the Geologists' Association 123(5). 779–786. Accessed 2019-10-13.
- Varela, A.N.; D. G. Poiré; T. Martin; A. Gerdes; F. J. Goin; J. N. Gelfo, and S. Hoffmann. 2012. U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: Its relationship with the evolution of the Austral Basin. doi:10.5027/andgeoV39n3-a01 available under a Creative Commons Attribution 4.0 International License
- Ezcurra, M.D.; F.L. Agnolin, and F.E. Novas. 2010. An abelisauroid dinosaur with a non-atrophied manus from the Late Cretaceous Pari Aike Formation of southern Patagonia.
Further reading
- J. F. Petrulevicius, A. N. Varela, A. Iglesias, A. B. Zamuner, and D. G. Poiré. 2014. First Cenomanian record of insects in the southern Hemisphere, with Perforissidae (Fulgoroidea) and Cupedidae (Coleoptera) from southern Patagonia, Argentina. Cretaceous Research 51:174-185
- J. P. O'Gorman and A. N. Varela. 2010. The oldest lower Upper Cretaceous plesiosaurs (Reptilia, Sauropterygia) from Southern Patagonia, Argentina. Ameghiniana 47(4):447-459
- A. Iglesias, A. B. Zamuner, D. G. Poiré and F. Larriestra. 2007. Diversity, taphonomy, and palaeoecology of an angiosperm flora from the Cretaceous (Cenomanian-Coniacian) in southern Patagonia, Argentina. Palaeontology 50(2):445-466
- F. J. Goin, D. G. Poire, M. S. De Fuente, A. L. Cione, F. E. Novas, E. S. Bellosi, A. Ambrosio, O. Ferrer, N. D. Canessa, A. Carloni, J. Ferigolo, A. M. Ribeiro, M. S. Sales Viana, M. A. Reguero, M. G. Vucetich, S. Marenssi, M. F. Lima Filho and S. Agostinho. 2002. Paleontologia y geologia de los sedimentos del cretacico superior aflorantes al sur del rio shehuen (Mata Amarilla, Provincia de Santa Cruz, Argentina). Actas del XV Congreso Geologico Argentino, El Calafate, 2002 1-6
- M. B. Aguirre Urreta. 1989. The Cretaceous decapod Crustacea of Argentina and the Antarctic Peninsula. Palaeontology 32(3):499-552
- J. Frenguelli. 1953. La Flora Fósil de la región del Alto Río Chalia en Santa Cruz (Patagonia). Paleontología. Notas del museo XVI(98):239-257
- F. Ameghino. 1899. Nota preliminar sobre el Loncasaurus argentinus un representante de la familia de los Megalosauridae en la República Argentina [Preliminary note on Loncasaurus argentinus, a representative of the family Megalosauridae in the Argentine Republic]. Anales de la Sociedad Científica Argentina 47:61-62