Chacaico Sur, Lajas: Early/Lower Callovian, Argentina
collected by Gasparini, Spaletti, and paleobotanists of the Museo de La Plata 1991
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Reptilia
- Plesiosauria
- Cryptoclididae
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cf. Muraenosaurus sp.
Seeley 1874
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4 specimens | |||||||||
| Cervical vertebrae: MOZ 6003, 6004, 6010; and a radius (MOZ 6005) | ||||||||||
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cf. Cryptoclidus sp.
(Seeley 1892)
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3 specimens | |||||||||
| MOZ 6006, 1011 (cervical vertebrae), 6007 (radius) | ||||||||||
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Reptilia
- Plesiosauria
- Pliosauridae
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Pliosauridae indet.
Seeley 1874
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1 specimen | |||||||||
| MOZ 6002, cervical centrum | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Argentina | State/province: | Neuquen |
| Coordinates: | 39.3° South, 70.3° West (view map) | ||
| Paleocoordinates: | 36.5° South, 31.7° West | ||
| Basis of coordinate: | stated in text | ||
| Geographic resolution: | small collection |
Time
| Period: | Jurassic | Epoch: | Middle Jurassic |
| Stage: | Callovian | 10 m.y. bin: | Jurassic 5 |
| Key time interval: | Early/Lower Callovian | ||
| Age range of interval: | 165.30000 - 161.50000 m.y. ago |
Stratigraphy
| Formation: | Lajas | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: Uppermost part of the middle Lajas Formation (early Callovian) | |||||
Lithology and environment
| Primary lithology: | dunes sandstone |
| Includes fossils? | Y |
| Lithology description: The intermediate section of the Lajas Formation contains the plesiosaurs remains near the top. This section includes about 2/3 the thickness of the formation. It is characterized by large sandstone bodies of cosets (sandwaves) tens of metres thick, that can be traced for considerable distances. The sandstones are cross-bedded as amalgamated tridimensional sets (dunes). SIgmoidal foresets, numerous reactivation surfaces, and alternating tractional (sandy) and fall-out laminae (rich in fine carbonized vegetal detritus) in the foresets, are conspicuous features of these sandstones. Some bipolar or herringbone cross-bedding is also present. According to their sedmintary attributes, these sandstone bodies represent extensive fields of tidal sand bars developed in shallow marine environments. | |
| Environment: | deltaic indet. |
| Geology comments: Tidally-influenced delta | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | surface (in situ),field collection | ||
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | Gasparini, Spaletti, and paleobotanists of the Museo de La Plata | Collection dates: | 1991 |
| Collection method comments: MOZ, Museo Olsacher, Zapala, Neuquén, Argentina | |||
Metadata
| Database number: | 140300 | ||
| Authorizer: | P. Mannion, R. Benson | Enterer: | J. Tennant, R. Benson |
| Modifier: | R. Benson | Research group: | vertebrate |
| Created: | 2013-03-07 05:49:00 | Last modified: | 2013-04-01 13:38:06 |
| Access level: | the public | Released: | 2013-03-07 05:49:00 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 46091. | Z. Gasparini and L. Spalletti. 1993. First Callovian plesiosaurs from the Neuquen Basin, Argentina. Ameghiniana 30(3):245-254 [R. Benson/R. Benson/F. Aspromonte] |
Secondary references:
| 45364 | Z. Gasparini and M. Fernández. 2005. Jurassic marine reptiles of the Neuquen Basin: records, faunas, and their palaeobiogeographic significance. In G. D. Viega, L. A. Spalletti, J. A. Howell, E. Schwarz (eds.), The Neuquen Basin, Argentina: A Case Study in Sequence Stratigraphy and Basin Dynamics; Geological Society, London, Special Publications 252:279-294 [P. Mannion/J. Tennant/F. Aspromonte] |