Cerro Negro, R.N. 40: Valanginian, Argentina
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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unclassified
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Elasmosauridae indet.
Cope 1869
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1 element | |||||||||
| PV-6891-MOZ, isolated cervical vertebra | ||||||||||
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= Plesiosauria indet.
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O'Gorman et al. 2015 | |||||||||
| see common names | ||||||||||
Geography
| Country: | Argentina | State/province: | Neuquen |
| Coordinates: | 38.8° South, 70.0° West (view map) | ||
| Paleocoordinates: | 38.0° South, 33.2° West | ||
| Basis of coordinate: | stated in text | ||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Early Cretaceous |
| Stage: | Valanginian | 10 m.y. bin: | Cretaceous 1 |
| Key time interval: | Valanginian | Ammonoid zone: | Pseudofavrella angulatiformis |
| Age range of interval: | 139.8 - 132.6 m.y. ago |
Stratigraphy
Lithology and environment
| Primary lithology: | black,gray lithified mudstone |
| Secondary lithology: | tabular,shelly/skeletal lithified "limestone" |
| Lithology description: "Three facies were recognized. The first one consists of black and gray mudrocks, and appears only at the base of the section. It was probably deposited in a low energy offshore subenvironment, under the stormweather wave base. Intercalated mudrocks and fossiliferous limestones compose the second facies. The limestones are tabular, 0.5 m thick in average, and comprise reworked and fragmented fauna, including plesiosaur remains PV-6894/1-2-MOZ. They were interpreted as storm deposits. The mudrocks represent pelagic background sediments and contained most of the plesiosaur remains studied in this paper (PV-6890/1-10-MOZ, PV-6891-MOZ, PV-6892-MOZ, and PV-6893/1-23-MOZ). This facies has been interpreted as a transitional subenvironment, between the fairweather and the stormweather wave base. The last facies consists mainly of heterolithic sandstones and amalgamated coquinas, and occurs at the top of shallowing-up cycles that begin with facies two. It contains reworked mollusks and corals, and a diverse assemblage of trace fossils. It represents a lower to upper shoreface subenvironment, between low tide level and fairweather wave base." | |
| Environment: | transition zone/lower shoreface |
| Geology comments: "In agreement with Spalletti (1992) and Brinkmann (1994), the Lower Member of the Agrio Formation was interpreted as deposited in a relatively shallow and warm marine environment (offshore to upper shoreface) under periodical storm
influence." | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Spatial orientation: | random |
| Abundance in sediment: | rare |
| Fragmentation: | occasional |
| Spatial resolution: | parautochthonous |
Collection methods and comments
| Collection excludes: | some macrofossils |
| Collection methods: | field collection |
| Collection size: | 1 specimens |
| Reason for describing collection: | general faunal/floral analysis |
| Collection method comments: "The described and figured material is deposited in the following collection under the catalogue number listed in the text: Museo Juan Olsacher. Direccion General de Mineria de la Provincia de Neuquen. Olascoaga 421, Zapala (8340), Neuquon, Argentina." | |
Metadata
| Database number: | 102086 | ||
| Authorizer: | M. Carrano, E. Vlachos | Enterer: | H. Street, F. Aspromonte |
| Modifier: | F. Aspromonte | Research group: | vertebrate |
| Created: | 2011-01-08 07:44:08 | Last modified: | 2023-11-07 17:19:37 |
| Access level: | the public | Released: | 2011-01-08 07:44:08 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 34690. | D. G. Lazo and M. Cichowolski. 2003. First plesiosaur remains from the Lower Cretaceous of the Neuquen Basin, Argentina. Journal of Paleontology 77(4):784-789 [M. Carrano/H. Street/F. Aspromonte] |
Secondary references:
| 86336 | J. P. O'Gorman, D. G. Lazo, L. Luci, C. S. Cataldo, E. Schwarz, M. Lescano, and M. B. Aguirre-Urreta. 2015. New plesiosaur records from the Lower Cretaceous of the Neuquén Basin, west-central Argentina, with an updated picture of occurrences and facies relationships. Cretaceous Research 56:372-387 [E. Vlachos/F. Aspromonte] |