Besano (Scisti bituminosi): Anisian - Ladinian, Italy
collected by B. Peyer, among others

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Helveticosauridae
Eusaurosphargis dalsassoi n. gen., n. sp. Nosotti and Rieppel 2003
Nosotti and Rieppel 2003 1 specimen
BES SC 390
Reptilia - Tanystropheidae
Macrocnemus bassanii n. gen., n. sp. (Nopcsa 1930)
3 individuals
"Exemplar Besano I" (type), "Exemplar Besano II", "Exemplar Besano III"; all are stored in the MSNM
Reptilia - Placodontia - Cyamodontidae
Cyamodus hildegardis Peyer 1931
Scheyer 2010 1 specimen
MSNM V458, juvenile with partial postcranial skeleton
Reptilia - Eosauropterygia - Pachypleurosauridae
Pachypleurosaurus edwardsi n. sp. (Sander 1989)
Carroll and Gaskill 1985
Reptilia - Eosauropterygia - Nothosauridae
Nothosaurus cf. juvenilis Edinger 1921
Renesto 2010 1 specimen
BES SC 1736, nearly complete skeleton (lacking most of skull)
Cephalopoda - Ceratitida - Ceratitidae
Ceratites brembanus Mojsisovics 1882
von Mojsisovics 1882 1 specimen
Ceratites trinodosus (von Mojsisovics 1878)
von Mojsisovics 1882 1 specimen
Cephalopoda - Ceratitida - Danubitidae
Balatonites euryomphalus (Benecke 1866)
von Mojsisovics 1882 1 specimen
Balatonites arietiformis Mojsisovics 1882
von Mojsisovics 1882 1 specimen
see common names

Geography
Country:Italy State/province:Piedmont County:Varese
Coordinates: 45.9° North, 8.9° East (view map)
Paleocoordinates:7.5° North, 21.0° East
Basis of coordinate:estimated from map
Geographic resolution:small collection
Time
Period: Triassic Epoch: Middle Triassic
Stage: Anisian - Ladinian 10 m.y. bin: Triassic 2
Key time interval: Anisian - Ladinian
Age range of interval: 247.2 - 237 m.y. ago
Stratigraphy
Formation:Besano
Stratigraphic resolution:formation
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). [...] 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
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,mechanical,survey of museum collection
Reason for describing collection:taxonomic analysis
Collectors:B. Peyer, among others
Metadata
Also known as:Cava di Besano; beds equivalent to those at Monte San Giorgio
Database number:86708
Authorizer:J. Mueller, A. Dunhill, G. Lloyd Enterer:T. Liebrecht, B. Allen, G. Lloyd
Modifier:T. Liebrecht Research group:vertebrate
Created:2009-02-13 11:45:55 Last modified:2009-02-20 07:07:50
Access level:the public Released:2009-02-13 11:45:55
Creative Commons license:CC BY
Reference information

Primary reference:
29195. E. Kuhn-Schnyder. 1962. Ein weiterer Schädel von Macrocnemus bassanii Nopcsa aus der anisischen Stufe der Trias des Monte San Giorgio (Kt. Tessin, Schweiz). Palaeontologische Zeitschrift 36:110-133 [J. Mueller/T. Liebrecht]

Secondary references:

66899 R. L. Carroll and P. Gaskill. 1985. The nothosaur Pachypleurosaurus and the origin of plesiosaurs. Philosophical Transactions of the Royal Society B 309:343-393 [A. Dunhill/B. Allen]
66732 C. G. Diedrich. 2011. The shallow marine placodont Cyamodus of the central European Germanic Basin: its evolution, paleobiogeography and paleoecology. Historical Biology 23(4):391-409 [A. Dunhill/B. Allen/B. Allen]
55415 S. Nosotti and O. Rieppel. 2003. Eusaurosphargis dalsassoi n. gen. n. sp., a new, unusual diapsid reptile from the Middle Triassic of Besano (Lombardy, N Italy). Memoire della Societa Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano 31(3):1-33 [G. Lloyd/G. Lloyd]
66893 S. Renesto. 2010. A new specimen of Nothosaurus from the latest Anisian (Middle Triassic) Besano formation (Grenzbitumenzone) of Italy. Rivista Italiana di Paleontologia e Stratigrafia 116(2):145-160 [A. Dunhill/B. Allen]
66733 T. M. Scheyer. 2010. New interpretation of the postcranial skeleton and overall body shape of the placodont Cyamodus hildegardis Peyer, 1931 (Reptilia, Sauropterygia). Palaeontologica Electronica 13(2):15A [A. Dunhill/B. Allen]
66734 T. M. Scheyer, J. M. Neenan, S. Renesto, F. Saller, H. Hagdorn, H. Furrer, O. Rieppel and A. Tintori. 2012. Revised paleoecology of placodonts – with a comment on ‘The shallow marine placodont Cyamodus of the central European Germanic Basin: its evolution, paleobiogeography and paleoecology’ by Diedrich (2011). Historical Biology 24(3):257-267 [A. Dunhill/B. Allen]
73139 E. von Mojsisovics. 1882. Die Cephalopoden der Mediterranen Triasprovinz. Abhandlungen der Kaiserlich-Königlichen Geologischen Reichsanstalt 10:1-322 [A. Dunhill/B. Allen]