East shore, Ezequiel Ramos Mexía Reservoir: Early Cenomanian, Argentina
collected by R. Spedale 1998 2019
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Reptilia
- Pterosauria
- Azhdarchidae
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Azhdarchidae indet.
Nessov 1984
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Agnolín et al. 2023 | 1 specimen | ||||||||
| MPCA-PV 2003, posterior half of a middle cervical vertebra | ||||||||||
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Reptilia
- Theropoda
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Bicentenaria argentina n. gen., n. sp.
Novas et al. 2012
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131 specimens | |||||||||
| MPCA 865, posterior half of skull articulated w/lower jaws; MPCA 866, ~130 bones, incl. frags of 2 articulated premaxillae w/3 pairs of teeth, incomplete R maxilla w/1 tooth, frags of 17 dorsal vertebrae, 14 sacral vertebrae, 20 caudal vertebrae, frags of 2 scapulae, caudodorsal corner of R coracoid, proximal ends of 3 ulnae, distal end of radius, 8 manual unguals, frags of L ilium, proximal frags of 5 pubic shafts, 5 inc. femora, proximal thirds of 2 L tibiae & distal end of R, R astragalus, frags of 5 metatarsals, 15 non-ungual pedal phalanges, 8 pedal unguals, & several isolated rib frags. Collected bones include 3 left femora w/approx. same size (ca. 31 cm long), indicating at least 3 large different specimens. These match with the size observed in several isolated dorsal, sacral and caudal vertebrae w/a closed neurocentral suture. The existence of a R distal femur with an identical morphology, but considerably smaller than the largest ones, indicates the presence of probably younger individuals in the bone assemblage. This statement is supported by the presence of a fragmentary maxilla bearing a tiny tooth with a crown height of 8 mm, obviously corresponding to a juvenile individual. | ||||||||||
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Reptilia
- Testudines
- Chelidae
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Chelidae indet.
Gray 1825
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Agnolín et al. 2023 | |||||||||
| Some turtle plates | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Argentina | State/province: | Río Negro |
| Coordinates: | 39.5° South, 68.9° West (view map) | ||
| Paleocoordinates: | 46.5° South, 45.2° West | ||
| Basis of coordinate: | stated in text | ||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Late Cretaceous |
| Stage: | Cenomanian | 10 m.y. bin: | Cretaceous 5 |
| Key time interval: | Early Cenomanian | ||
| Age range of interval: | 100.5 - 93.9 m.y. ago |
Stratigraphy
| Geological group: | Neuquén | Formation: | Candeleros | ||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: Upper levels of the Candeleros Formation (Cenomanian, early Late Cretaceous; Leanza et al., 2004), Río Limay Subgroup, Neuquén Group | |||||
Lithology and environment
| Primary lithology: | medium,red sandstone |
| Secondary lithology: | medium,red mudstone |
| Includes fossils? | Y |
| Includes fossils? | Y |
| Lithology description: The rocks of the Candeleros Formation which yielded the remains of Bicentenaria argentina are made up by red medium sized sandstones and mudstones, with abundant dark-brownish paleosoils representing a fluvial environment under braided and meandering regimes, as well as in aeolian conditions (Leanza et al., 2004; Garrido, 2011) | |
| Environment: | fluvial indet. |
Taphonomy
| Modes of preservation: | body |
| Degree of concentration: | -single event |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | poor |
| Abundance in sediment: | abundant |
| Disassociated major elements: | many |
| Fragmentation: | frequent |
| Spatial resolution: | parautochthonous |
Collection methods and comments
| Collection excludes: | some macrofossils | ||
| Collection methods: | selective quarrying,surface (in situ),mechanical,field collection | ||
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | R. Spedale | Collection dates: | 1998 and 2019 |
| Collection method comments: MPCA-PV, Vertebrate Paleontology Collection, Museo Provincial “Carlos Ameghino”, Río Negro province, Argentina.
The skeletal remains of *Bicentenaria argentina* were collected by Mr. Raul Spedale in 1998 during an exceptional fall in the water level of the Ezequiel Ramos Mexía Reservoir (Fig. 1). All the bones were collected from a single quarry roughly 40 centimeters long, 30 centimeters wide, and 50 centimeters thick. The specimen (MPCA-PV 2003) was found during a field trip performed under the project of relocation and georeferencing of fossil sites in the Río Negro province, carried out by the former Dirección de Patrimonio y Museos from the Río Negro goverment and supported by some professionals of the Universidad Nacional de Rio Negro (UNRN) in June, 2019. | |||
Metadata
| Database number: | 132347 | ||
| Authorizer: | R. Benson, E. Vlachos | Enterer: | R. Benson, F. Aspromonte |
| Modifier: | F. Aspromonte | Research group: | vertebrate |
| Created: | 2012-08-14 18:25:44 | Last modified: | 2023-11-02 11:09:54 |
| Access level: | the public | Released: | 2012-08-14 18:25:44 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 42624. | F. E. Novas, M. D. Ezcurra, F. L. Agnolin, D. Pol, and R. Ortíz. 2012. New Patagonian Cretaceous theropod sheds light about the early radiation of Coelurosauria. Revista del Museo Argentino de Ciencias Naturales, nuevo serie 14(1):57-81 [R. Benson/R. Benson/M. Carrano] |
Secondary references:
| 86257 | F. L. Agnolín, S. Rozadilla, R. D. Juárez-Valieri and J. G. Meso. 2023. Oldest azhdarchid (Pterosauria) record from South America. Revista del Museo Argentino de Ciencias Naturales 25(2):309-314 [E. Vlachos/F. Aspromonte] |