List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Equisetopsida
- Cheirolepidiaceae
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Pararaucaria patagonica
Wieland 1935
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Stockey 1977 | |||||||||
| Wieland 1929 | ||||||||||
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Equisetopsida
- Araucariaceae
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Brachyphyllum indet.
Brongniart 1828
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Araucaria cf. mirabilis
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Agathoxylon matildense
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| see common names | ||||||||||
Geography
| Country: | Argentina | State/province: | Santa Cruz |
| Coordinates: | 48.0° South, 68.0° West (view map) | ||
| Paleocoordinates: | 44.8° South, 26.7° West |
Stratigraphy
| Geological group: | Bahia Laura | Formation: | La Matilde |
Lithology and environment
| Primary lithology: | tabular,planar lamination,burrows,very fine,very coarse,tuffaceous poorly lithified "volcaniclastic" |
| Secondary lithology: | breccia |
| Lithology description: In the studied section at the Monumento Natural Bosques Petrificados locality, the pyroclastic deposits are the most important lithologic component; the preserved stratigraphic section is about 125 m, affected at the upper portion by north–south normal faults (see Fig. 1.2). The succession begins with stratified siltstones and rare massive paleochannels. The lower fossiliferous level (“Barda Blanca” or “BB” in situ forest) developed on a lateral extended paleosol with abundant root traces and vegetal remains. The in situ stumps are covered by 12 m of pyroclastic deposits, with accretionary lapilli and laminated tuffs at the base (surge deposits?) and massive tuffs upwards (fallen ash deposits). It continues with massive intraformational breccias, deposited by debris-flow and hyperconcentrated flows during the reworking of pyroclastic sediments. These deposits are overlain by an upward coarsening interval of reworked tuffs (15– 19 m), characterized by fine laminations, abundant burrows (Skolithos and Planolites), current ripples and impressions of herbaceous equisetaleans (Falaschi et al., 2009); these deposits are interpreted as a succession of shallow water bodies with important organic activity, with an increase of the terrigenous influence upwards. At the top of this shallow water succession the second fossiliferous level developed (“Bosque Principal” or “BP” in situ forest), over a mottled paleosol with abundant, unidentified vegetal remains. The stratigraphic section is interrupted by normal faults, but the upper deposits of the La Matilde Formation have more defined fluvial characteristics with paleochannels deposited by dilute flows. | |
| Environment: | fluvial-lacustrine indet. |
Taphonomy
| Modes of preservation: | body,cast,mold/impression,trace,recrystallized,original silica,original carbon,replaced with silica |
| Size of fossils: | macrofossils |
Collection methods and comments
| Reason for describing collection: | general faunal/floral analysis |
Metadata
| Database number: | 200039 | ||
| Authorizer: | P. Wilf | Enterer: | E. Stiles |
| Modifier: | E. Stiles | Research group: | paleobotany |
| Created: | 2019-02-26 15:52:05 | Last modified: | 2019-02-27 11:32:21 |
| Access level: | the public | Released: | 2019-02-26 15:52:05 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 68015. | P. Falaschi, J. Grosfeld, A. B. Zamuner, N. Foix, and S. M. Rivera. 2011. Growth architecture and silhouette of Jurassic conifers from La Matilde Formation, Patagonia, Argentina. Palaeogeography, Palaeoclimatology, Palaeoecology 302(43):122-141 [P. Wilf/E. Stiles] |
Secondary references:
| 68026 | R. A. Stockey. 1977. Reproductive Biology of the Cerro Cuadrado (Jurassic) Fossil Conifers: Pararaucaria patagonica. American Journal of Botany 64(6):733-744 [P. Wilf/E. Stiles] |