Open Session - SWISS GEOSCIENCE MEETINGs

More documents

Recommendations

Info

Mémoires et Travaux de l’Ecole pratique des Hautes Études, Institut de Montpellier 21, 475-499. Mojon, P.O., Engesser, B., Berger, J.P., Bucher, H. & Weidmann, M. 1985: Sur l'âge de la Molasse d'eau douce inférieure de Boudry, Neuchâtel. Eclogae geologicae. Helvetiae 78, 631-667. Picot, L., Becker, D. & Berger, J.-P. 1999: Nouvelles données paléoécologiques et biostratigraphiques sur la formation des Calcaires delémontiens (« Delsberger Kalke », Oligocène terminal, Jura Suisse). Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 214, 433-462. Theiler, E. 1998: Geologie im Gebiet der Tiergartenantiklinale (JU) mit besonderer Berücksichtigung der Molasseeinheiten. Unpublished Master Thesis, University of Fribourg, 93 pp. 3.11 New excavations in the Cassina levels (Monte San Giorgio, Middle Triassic) preliminary reports Renesto Silvio*, Lombardo Cristina**, Stockar Rudolf*** *Dipartimento di Biologia Strutturale e Funzionale, Università degli Studi dell’Insubria, via Dunant 3 I-21100, Varese, Italy (silvio.renesto@ uninsubria.it) **Dipartimento di Scienze della Terra, Università degli Studi di Milano, via Mangiagalli 34, I-20133 Milano, Italy (cristina.lombardo@unimi.it) *** Museo Cantonale di Storia Naturale, viale C. Cattaneo 4, CH-6900 Lugano, Switzerland, (rudolf.stockar@ti.ch) Among the calcilutite sequence of the Early Ladinian Lower Meride Limestone of Monte San Giorgio (Unesco WHL, Switzerland) three fossiliferous beds are known: the Cava inferiore, Cava superiore and Cassina beds. These latter were originally investigated in 1933 by the University of Zürich which carried out further excavations in 1937 and in the period 1971-1975. Along with different reptile taxa (e. g. Ceresiosaurus lanzi, Neusticosaurus edwardsii, Macrocnemus bassanii and Tanystropheus meridensis) a large fish fauna was collected then, dominated by well preserved Saurichthys (S. curionii and S. macrocephalus), along with smaller actinopterygians referred to three different species: Peltopleurus sp. (one specimen, Bürgin 1992), Archaeosemionotus sp. nov. and Macrosemiidae gen. et sp. nov. (both listed in Bürgin 1999, but not described so far). In 2006 the Museo cantonale di storia naturale (Lugano) undertook a new excavation in the Cassina beds at the type locality, to investigate bed by bed on a surface of about 40 m 2 the whole fossiliferous succession. In the new site the fossiliferous beds represent an almost 3m thick interval of mainly interbedded finely laminated, organic-rich shales and limestones with intercalated thicker bituminous micritic and marly limestones. Normal graded calcarenites, showing erosional surfaces and bearing scattered clearly reworked fossil fragments, suggest the instability of the basin margins and the occasional influence of turbidity currents. Volcaniclastic layers (tuffs and bentonites) are frequent throughout the section. The new excavations revealed profitable, yielding an interesting vertebrate fauna. Besides isolated bones and teeth of sauropterygian reptiles, interesting and well-preserved fossil fishes have been found, providing further information about the extraordinary ichthyofauna from the Monte San Giorgio area. In the Cassina beds both neopterygians, as Archaeosemionotus and Eosemionotus, and paleopterygians, as Saurichthys and Peltopleurus, are represented. The medium-sized Archaeosemionotus is characterized by the mosaic-like covering of the cheek and the well-developed dentition, probably adapted to an hemi-durophagous diet; this genus has been found in other levels from Monte San Giorgio, with at least three different species (Bürgin 1999). On the contrary, the smaller Eosemionotus, with its typical thin and elongate teeth on premaxillary and dentary bones and the small fins with large fulcra, is reported for the first time in these levels. Peltopleurus, is widely represented throughout the different levels of Monte San Giorgio, with a surprising intra- and interspecific variability (Bürgin 1992; Lombardo 1999). The most abundant findings, however, belong to the large predator actinopterygian fish Saurichthys, with many complete and well preserved specimens (mainly S. curionii, but S. macrocephalus is also present). Among yet prepared material, four Saurichthys specimens contained several skulls of small specimens that can be identified as embryos. In one of these specimens, the embryos are very small and each skull is associated to a tiny, narrow and white cylinder (Fig. 1) that is either curled or comma shaped. Chemical investigation revealed that these structures are made of phosphate. The chemical compostion, size and structure of these cylinders compared to the associated skulls, suggests that they may well represent the fossilized musculature of the embryos and each segment corresponding to a somite. This finding is of great scientific relevance because it represents the first case of preservation of soft tissues and even of postcranial structures in embryos of Saurichthys. 12 Symposium 3: Palaeontology
130 Symposium 3: Palaeontology REFERENCES Bürgin, T. 1992: Basal Ray-finned fishes (Osteichthyes, Actinopterygii) from the Kalkschieferzone (Uppermost Ladinian) near Meride (Canton Ticino, Southern Switzerland). Eclogae geol. Helv. 88/3, 803-826. Bürgin, T. 1999: Middle Triassic marine fish faunas from Switzerland. In Arratia G. & Schultze H.-P. (eds.): Mesozoic Fishes 2 – Systematics and Fossil Record. Pfeil, München, 481-494. Lombardo, C. 1999: Sexual dimorphism in a new species of the Actinopterygian Peltopleurus from the Triassic of Northern Italy. Palaeontology, 42/4, 741-760. Figure 1. A small Saurichthys embryo with axial musculature preserved.
Page 1 and 2:
Abstract Volume 6 th Swiss Geoscien
Page 3 and 4:
2 Plenary Session
Page 5 and 6:
Plenary Session 0. Plenary Session
Page 7 and 8:
6 Plenary Session 3 Annual Opening
Page 9 and 10:
8 Plenary Session Hochwasserschutz
Page 11 and 12:
10 Symposium 1: Structural Geology,
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Symposium 1: Structural Geology, Te
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Symposium 1: Structural Geology, Te
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
2 Symposium 2: Mineralogy-Petrology
Page 75 and 76:
Symposium 2: Mineralogy-Petrology-G
Page 77 and 78:
6 Symposium 2: Mineralogy-Petrology
Page 79 and 80: 8 Symposium 2: Mineralogy-Petrology
Page 81 and 82: 80 Symposium 2: Mineralogy-Petrolog
Page 95 and 96: Symposium 2: Mineralogy-Petrology-G
Page 101 and 102: 100 Symposium 2: Mineralogy-Petrolo
Page 115 and 116: 11 Symposium 3: Palaeontology 3. Pa
Page 117 and 118: 116 Symposium 3: Palaeontology 3.2
Page 119 and 120: 118 Symposium 3: Palaeontology 3.3
Page 121 and 122: 120 Symposium 3: Palaeontology AG 0
Page 123 and 124: 122 Symposium 3: Palaeontology 3. F
Page 125 and 126: 12 Symposium 3: Palaeontology Figur
Page 127 and 128: 126 Symposium 3: Palaeontology Figu
Page 129: 128 Symposium 3: Palaeontology REFE
Page 133 and 134: 132 Symposium 3: Palaeontology Figu
Page 135 and 136: 13 Symposium 3: Palaeontology 3.1 H
Page 137 and 138: 136 Symposium 4: Meteorology and cl
Page 139 and 140: 138 Symposium 4: Meteorology and cl
Page 141 and 142: 1 0 Symposium 4: Meteorology and cl
Page 143 and 144: 1 2 Symposium 4: Meteorology and cl
Page 145 and 146: 1 Symposium 4: Meteorology and clim
Page 147 and 148: 1 6 Symposium 5: Quaternary Researc
Page 155 and 156: 1 Symposium 5: Quaternary Research
Page 161 and 162: 160 Symposium 5: Quaternary Researc
Page 165 and 166: 16 Symposium 5: Quaternary Research
Page 173 and 174: 1 2 Symposium 6: Apply! Snow, ice a
Page 175 and 176: 1 Symposium 6: Apply! Snow, ice and
Page 181 and 182:
180 Symposium 6: Apply! Snow, ice a
Page 183 and 184:
Page 185 and 186:
18 Symposium 6: Apply! Snow, ice an
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
1 0 Symposium 6: Apply! Snow, ice a
Page 193 and 194:
Page 195 and 196:
1 Symposium 6: Apply! Snow, ice and
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
20 Symposium 6: Apply! Snow, ice an
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
210 Symposium 7: Geofluids and rela
Page 213 and 214:
Page 215 and 216:
21 Symposium 7: Geofluids and relat
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
22 Symposium 7: Geofluids and relat
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
230 Symposium 8: Building Stones -
Page 233 and 234:
Page 235 and 236:
23 Symposium 8: Building Stones - a
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
2 0 Symposium 9: Natural Hazards an
Page 243 and 244:
Page 245 and 246:
2 Symposium 9: Natural Hazards and
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
Page 253 and 254:
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
260 Symposium 9: Natural Hazards an
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
Page 273 and 274:
2 2 Symposium 10: Anthropogenic imp
Page 275 and 276:
2 Symposium 10: Anthropogenic impac
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
280 Symposium 10: Anthropogenic imp
Page 283 and 284:
282 Symposium 10: Anthropogenic imp
Page 285 and 286:
28 Symposium 11: Social Aspects of
Page 287 and 288:
Page 289 and 290:
Page 291 and 292:
2 0 Symposium 11: Social Aspects of
Page 293 and 294:
2 2 Symposium 11: Social Aspects of
Page 295 and 296:
2 Symposium 11: Social Aspects of W
Page 297 and 298:
2 6 Symposium 12: Data acquisition,
Page 299 and 300:
2 8 Symposium 12: Data acquisition,
Page 301 and 302:
300 Symposium 12: Data acquisition,
Page 303 and 304:
Page 305 and 306:
Page 307 and 308:
Page 309 and 310:
Page 311 and 312:
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
328 Symposium 13: Global change - l
Page 331 and 332:
Page 333 and 334:
Page 335 and 336:
33 Symposium 13: Global change - le
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
3 0 Symposium 14: Deep Earth - From
Page 343 and 344:
Page 345 and 346:
3 Symposium 14: Deep Earth - From C
Page 347 and 348:
Page 349 and 350:
3 8 INDEX Index A Abbühl L. 156, 1
Page 351 and 352:
3 0 INDEX I Ibele T. 30, 46 Iberg A
Page 353 and 354:
3 2 INDEX Stampfli G.M. 7, 48, 346
show all

Open Session - SWISS GEOSCIENCE MEETINGs

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?