San Salvatore Dolomite | |
---|---|
Stratigraphic range: Late Anisian (Illyrian) | |
Type | Geological formation |
Sub-units | Rasa Dolomite |
Underlies | Besano Formation, Pizzella Marls |
Overlies | Bellano Formation, Fenera Annunziata Sandstone, Pissone Dolomite |
Lithology | |
Primary | Dolomite |
Location | |
Region | Lombardy, Piedmont, Ticino |
Country | Italy Switzerland |
Extent | Southwestern Limestone Alps |
Type section | |
Named for | Monte San Salvatore |
The San Salvatore Dolomite, sometimes known as the Salvatore Dolomite or San Salvatore Formation, is a Middle Triassic (late Anisian) geological formation in Switzerland and Italy. The primarily lithology is micritic dolomite with a high proportion of algal mounds (stromatolites). [1] It corresponds to a thick warm-water carbonate platform on the northern edge of an island in what is now the Po Plain. This formation and its local equivalents are common in the hills around Lake Maggiore, Varese, and Lugano, preserving fossils of marine invertebrates such as ammonoids, gastropods, and bivalves. At its southernmost extent on Monte San Giorgio, only the lower part of the San Salvatore Dolomite is preserved. The middle and upper parts are replaced by the Besano Formation, San Giorgio Dolomite, and Meride Limestone, which were deposited in a deeper and more anoxic basin between carbonate platforms. [2] [3] [4] [5]
The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 242 Ma and ~237 Ma. The Ladinian was preceded by the Anisian and succeeded by the Carnian.
Ticinosuchus is an extinct genus of suchian archosaur from the Middle Triassic of Switzerland and Italy.
Monte San Giorgio is a Swiss mountain and UNESCO World Heritage Site near the border between Switzerland and Italy. It is part of the Lugano Prealps, overlooking Lake Lugano in the Swiss Canton of Ticino.
Macrocnemus is an extinct genus of archosauromorph reptile known from the Middle Triassic of Europe and China. Macrocnemus is a member of the Tanystropheidae family and includes three species. Macrocnemus bassanii, the first species to be named and described, is known from the Besano Formation and adjacent paleontological sites in the Italian and Swiss Alps. Macrocnemus fuyuanensis, on the other hand, is known from the Zhuganpo Formation in southern China. A third species, Macrocnemus obristi, is known from the Prosanto Formation of Switzerland and is characterized by gracile limbs. The name Macrocnemus is Greek for "long tibia".
Ticinepomis is an extinct genus of coelacanth lobe-finned fish which lived during the Middle Triassic period in what is now Switzerland. It contains two species, T. peyeri and T. ducanensis.
Besanosaurus is a genus of Middle Triassic ichthyosaur from Monte San Giorgio of Italy and Switzerland, containing the single species B. leptorhynchus. Besanosaurus was named by Cristiano Dal Sasso and Giovanni Pinna in 1996, based on the nearly complete flattened skeleton BES SC 999, the holotype specimen. This skeleton is preserved across multiple thin rock slabs spanning 3.5 by 4 metres when assembled and took thousands of hours to prepare. Additional specimens from Monte San Giorgio that have previously been considered separate genera, including a partial skull named Mikadocephalus and a well-preserved, largely complete skeleton, have been reinterpreted as additional specimens of Besanosaurus.
Eosaurichthys is an extinct genus of saurichthyid ray-finned fish that lived during the late Permian epoch in what is now China.
Serpianosaurus is an extinct genus of pachypleurosaurs known from the Middle Triassic deposits of Switzerland and Germany. It was a small reptile, with the type specimen of S. mirigiolensis measuring 75 cm (2.46 ft) long.
Luganoia is an extinct genus of prehistoric bony fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch. Fossils were recovered from the Besano Formation of Monte San Giorgio and Besano area and from the Zhuganpo Member of Guizhou, South China. It was also reported from the Ladinian of Spain.
Besania is an extinct genus of prehistoric bony fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern/southeastern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio area and the Prosanto Formation of canton Graubünden, Switzerland.
Ctenognathichthys is an extinct genus of prehistoric bony fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern/southeastern Switzerland and northern Italy.
Heptanema is an extinct genus of prehistoric coelacanth from the Middle Triassic (Ladinian) of northern Italy and southern Switzerland.
Meridensia is an extinct genus of prehistoric ray-finned fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio and Besano area at the Swiss-Italian boundary.
Wimanius is a genus of ichthyosaur from the Middle Triassic of Switzerland, containing a single species, Wimanius odontopalatus. It was described by Michael Maisch and Andreas Matzke in 1998 based on an incomplete skull from Monte San Giorgio, a mountain on the Swiss-Italian border. Wimanius possesses teeth on its palate, though whether they were located on the palatine or pterygoid is disputed. Other features of Wimanius include a large orbit and jugals with two rami of similar lengths. Different phylogenetic placements of Wimanius have been recovered by different studies, including it being a mixosaurid relative or a merriamosaur, and a monotypic family, Wimaniidae has been named for it. However, its validity has also been questioned, and synonymy with various other genera has been proposed.
Sinosaurichthys is an extinct genus of saurichthyid ray-finned fish, which existed in southwestern China during the Middle Triassic. Fossils have been found in the Upper Member of the Guanling Formation of two localities: Yangjuan of Panxian County, Guizhou Province, and Dawazi of Luoping, Yunnan Province, China.
Megachirella is an extinct genus of lepidosaur, possibly a stem-squamate that lived about 240 million years ago during the Middle Triassic and contains only one known species, Megachirella wachtleri. It is known from a partial skeleton discovered in the Dolomites of Northern Italy and was described in 2003.
Eusaurosphargis is an extinct genus of a diapsid reptile, known from the Middle Triassic Besano Formation of northern Italy and Prosanto Formation of south-eastern Switzerland. It contains a single species, Eusaurosphargis dalsassoi. It was a small reptile, measuring 20 cm (7.9 in) long.
Helveticosauridae is an extinct family of basal marine reptiles known from the Middle Triassic of southern Switzerland and northern Italy.
The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a short but fossiliferous succession of dolomite and black shale, is famous for its preservation of Middle Triassic (Anisian–Ladinian) marine life including fish and aquatic reptiles. It is exposed in the vicinity of Monte San Giorgio and is among the formations responsible for the area being designated as a UNESCO World Heritage Site. In Switzerland, it is also known as the Grenzbitumenzone. The Anisian-Ladinian boundary lies in the upper part of the Besano Formation.
Acronemus is an extinct genus of euselachian shark from the Middle Triassic of Switzerland. It is an enigmatic genus of shark with uncertain relations to other sharks. Though originally placed within Ctenacanthiformes, it is now considered Euselachii incertae sedis, due to its mixture of features similar to hybodontiforms and neoselachians. Originally, teeth from this genus were attributed to "Acrodus bicarinatus" while fin spines were named "Nemacanthus tuberculatus". Associated material showed they were the same animal, with the older specific epithet (tuberculatus) taking precedence. The shark was given the new genus Acrocnemus, containing a single species. Acronemus is found in the Anisian-age Grenzbitumenzone of Monte San Giorgio. It was a small shark measuring 30–35 cm (0.98–1.15 ft) long. A 2018 study considered it to be closely related to the early Carboniferous genus Tristychius as part of the family Tristychiidae as a basal euselachian, with hybodonts more more closely related to neoselachians than to Tristychiidae.