Point 902, Monte San Giorgio, Bed 164: Fassanian, Switzerland
collected 1953

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Eosauropterygia - Pachypleurosauridae
Serpianosaurus mirigiolensis Rieppel 1989
3 individuals
PIMUZ T 97, 3678, 3680
Actinopteri
López-Arbarello et al. 2016 4 specimens
Ticinolepis crassidens López-Arbarello et al. 2016
López-Arbarello et al. 2016 9 specimens
PIMUZ T 237, 248, 257, 285, 315, 331, 341, 358, 638
Ticinolepis longaeva López-Arbarello et al. 2016
López-Arbarello et al. 2016 1 specimen
PIMUZ T 226
see common names

Geography
Country:Switzerland State/province:Ticino County:Mendrisio
Coordinates: 45.9° North, 8.9° East (view map)
Paleocoordinates:8.8° North, 20.1° East
Basis of coordinate:estimated from map
Geographic resolution:small collection
Time
Period:Triassic Epoch:Middle Triassic
Stage:Ladinian 10 m.y. bin:Triassic 2
Key time interval:Fassanian Ammonoid zone: Curionii
Age range of interval:242.00000 - 239.70000 m.y. ago
Stratigraphy
Formation:Besano
Local section:Punkt 902 Local bed:164
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: The Besano Formation is also known as "Grenzbitumenzone" or "Scisti bituminosi". It comprises strata from the uppermost Anisian to the lowermost Ladinian.
Lithology and environment
Primary lithology:planar lamination,black,brown,gray dolomite
Secondary lithology:planar lamination,quartzose,black "shale"
Includes fossils?Y
Lithology description: "The Grenzbitumenzone [GBZ] of the Tessiner Kalkalpen is an alternation of dolomite beds of various thickness (3 up to 50 cm), numerous, thinner layers of finely laminated, black bituminous shales (Schwarzschiefer), and few, up to several centimeters thick, volcaniclastic interbeds (volcanic ashes). At the excavation site P.902 near Mirigioli at Monte San Giorgio, the total tickness of the GBZ, comprising the beds 3 to 186 at this location, was measured to be 15.8 m. The beds of the more or less laminated dolomites make up about 80% of the total thickness of the GBZ. Depending on the degree of weathering and on the content of organic matter (up to 12 weight %), the dolomite beds are dark grey, dark brown to light beige. In freshly-mined condition, in the galleries of the former mines, they are almost black (high organic matter content) or dark to medium grey. The the original carbonate mud is completely dolomitized. There is no evidence of other carbonate phases. The laminae of the mostly parallel and continuous fine lamination vary in thickness from 0.1 to 5 mm. In most cases the lamination is caused by a rhythmic change of the content of dolomite, clay minerals, and organic matter. However, in dolomite-rich laminae also graded bedding may be observed occasionally. [...] The black shales contain no or at most few carbonate. The content of organic matter ranges from 10 up to 40 weight %. The fine lamination of freshly-mined shale is well visible only in thin sections. Partly weathered, the black shale delaminates into thin (mostly less than 1 mm) laminae [...]. The lamination is caused by a change of organic matter, clay minerals, and quartz. The quartz is mainly biogenic. Radiolarians are very common and partly form small laminae of silica in the black shales." (translated from H.-P. Rieber, 2000, in D. Meischner (ed.) Europäische Fossillagerstätten, German edition)
Environment:lagoonal/restricted shallow subtidal Tectonic setting:passive margin
Geology comments: "The GBZ was deposited within a largely closed marine basin with restricted water circulation (Zorn 1971, Rieber et Sorbini 1983, Bernasconi, 1994). The basin was enclosed by carbonate platforms. The fine-grained sediments and missing evidence of reworking, the mostly complete preserved vertebrate skeletons which are not oriented indicate that there was at most a weak current at the bottom of the basin and that the sediments were deposited below wave base. The water depth of the basin is estimated to have been 30 to 100 m with a gradual deepening through time. The undisturbed lamination of the GBZ rocks and a lack of autochthonous benthos point out that the basin in which the GBZ generated had a stable stratification of the water column and that the bottom water was almost always anoxic and rich in H2S. The common remains of highly marine animals, primarily pelagic fish, ichthyosaurs, ammonoids, and daonellids prove that the surface waters had normnal salinity and was at least periodically connected to the waters of the Triassic Paleotethys." (translated from Rieber, 2000)
Sequence Stratigraphy: looks and sounds like the maximum flooding interval of a transgressive systems tract
Taphonomy
Modes of preservation:body,adpression
Size of fossils:macrofossils
Preservation of anatomical detail:excellent
Articulated whole bodies:many
Temporal resolution:time-averaged
Spatial resolution:autochthonous
Collection methods and comments
Collection excludes:all microfossils
Collection methods:bulk,survey of museum collection
Reason for describing collection:taxonomic analysis
Collection dates:1953
Metadata
Database number:86835
Authorizer:J. Mueller, M. Clapham Enterer:T. Liebrecht, M. Clapham
Modifier:M. Clapham Research group:vertebrate
Created:2009-02-19 16:45:12 Last modified:2022-06-17 20:14:51
Access level:the public Released:2009-02-19 16:45:12
Creative Commons license:CC BY
Reference information

Primary reference:
29226. O. Rieppel. 1989. A new pachypleurosaur (Reptilia: Sauropterygia) from the Middle Triassic of Monte San Giorgio, Switzerland. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 323(1212):1-73 [J. Mueller/T. Liebrecht/M. Uhen]

Secondary references:

59894 A. López-Arbarello, T. Bürgin, H. Furrer and R. Stockar. 2016. New holostean fishes (Actinopterygii: Neopterygii) from the Middle Triassic of the Monte San Giorgio (Canton Ticino, Switzerland). PeerJ 4(e2234):1-61 [M. Clapham/M. Clapham]