Saltrio Formation
| Saltrio Formation Stratigraphic range: Sinemurian ~196–190 Ma | |
|---|---|
| Type | Geological formation |
| Lithology | |
| Primary | Limestone |
| Location | |
| Coordinates | 45°54′N 8°54′E / 45.9°N 8.9°ECoordinates: 45°54′N 8°54′E / 45.9°N 8.9°E |
| Approximate paleocoordinates | 33°06′N 14°48′E / 33.1°N 14.8°E |
| Region | Lombardy |
| Country |
 |
| Type section | |
| Named for | Saltrio |
The Saltrio Formation is a geological formation in Italy. It dates back to the middle Sinemurian, and would have represented a beach-like environment, judging by the presence of marine fauna such as the nautiloid Cenoceras.[1]
Description
The ammonites from the Saltrio Formation allow the formation to be dated to the late Sinemurian. Animals probably lived in emerged parts of carbonated platform or an area to the northwest, whose presence had never been established. The latter possibility was suggested by Lualdi (1999), in which he analyzed the local geology based on the presence of terrestrial plants and terrigenous content (sands from igneous or metamorphic rocks exposed to sub-aerial erosion) in the limestones. Terrestrial plants are essentially represented by leaves and small branches of Araucarianas and Bennettitales, the typical flora of the early Mesozoic. However, plants and sand (which are not abundantly referred) can be carried by wind and ocean currents. Also, according to the most current paleogeographic maps, truly continental land located closer these Jurassic times lower were the Mountains of Sardinia, Corsica, distanced many tens of kilometers WNW.[2]
Large dinosaurs, carnivorous and herbivorous, were present at various icnojazidas of the lower Jurassic (Hettangian - Sinemurian) in the province of Trento, around 160 kilometres (99 mi) east of Saltrio, which changed the traditional view of the palaeoenvironments and paleogeography of the region, considered a tropical sea with small islands of the atoll type. Fossil footprints and tracks are preserved in tidal carbonates deposited in a relatively narrow carbonated platform in Trento, flanked to the east and west by relatively deep marine basins. Large theropods could not live in an atoll, since large areas had to be emersed to provide food and fresh water, and their herbivorous prey needed land with vegetation. The presence of vulcanodontids, cetiosaurs, primitive sauropods, heterodontosaurids, and scelidosaurs have been reported from the Calcari Grigi Group.
"It is more likely that the Peri-Adriatic Platforms worked with temporary continental bridges that connected with Laurasia Gondwana in central Tethis, allowing migration between the two hemispheres and colonization of local coastal habitats." "During the marine transgressions, some of these lands were isolated, implicating genetic Mutations in their terrestrial faunas, with typical biological consequences, as endemism and possible dwarfism".[3]
Vertebrate fauna
| Dinosaurs of the Saltrio Formation | ||||
|---|---|---|---|---|
| Taxa | Presence | Notes | Images | |
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Unranked:
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See also
References
- 1 2 3 4 Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 532–534. ISBN 0-520-24209-2.
- ↑ Dalla Vecchia, F.M. 2001. A new theropod dinosaur from the Lower Jurassic of Italy, Saltriosaurus. Dino Press. 3, 81-87.
- ↑ Cristiano Dal Sasso: Dinosaurs of Italy. In: Comptes Rendus Palevol. Bd. 2, Nr. 1, 2003.
Further reading
- F. M. Dalla Vecchia. 2001. Terrestrial ecosystems on the Mesozoic peri-Adriatic carbonate platforms: the vertebrate evidence. VII International Symposium on Mesozoic Terrestrial Ecosystems. Asociación Paleontología Argentina, Publicación Especial 7:77-83