Cocholgüe village, sea coast: Late/Upper Maastrichtian, Chile
collected by M. E. Suarez 2001–
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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unclassified
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aff. Grossouvreites sp.
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Otero et al. 2014 | |||||||||
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Osteichthyes indet.
(Huxley 1880)
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Otero et al. 2014 | |||||||||
| vertebrae of indeterminate bony fishes | ||||||||||
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Reptilia
- Plesiosauria
- Elasmosauridae
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Aristonectes sp.
Cabrera 1941
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1 individual | |||||||||
| SGO.PV.957 (holotype), skeleton including the skull, atlas-axis, twelve anterior cervicals, 23 middle-to-posterior cervicals, most of the trunk, both almost complete forelimbs, and most of the proximal portion of the right hind limb | ||||||||||
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= Aristonectes quiriquiensis n. sp.
Otero et al. 2014
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Otero et al. 2014 | |||||||||
| corrected as Aristonectes quiriquinensis | ||||||||||
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Reptilia
- Mosasauridae
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Halisaurus sp.
Marsh 1869
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Jiménez-Huidobro et al. 2019 | 1 specimen | ||||||||
| Q.3105, block with fragments of left and right dentaries and a fragmented right splenial; previously identified as cf. Plotosaurus sp. (Frey et al. 2016) | ||||||||||
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Reptilia
- Testudines
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Euclastes sp.
Cope 1870
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Parham et al. 2014 | 1 specimen | ||||||||
| SGO.PV.6504, a nearly complete skull that was found ventral surface up. The ventral portion of the skull posterior to the triturating surface is highly eroded so the contacts and shapes of most of the basicranium are obscured. The skull roof is largely complete, but crushed | ||||||||||
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Chondrichthyes
- Lamniformes
- Carchariidae
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Carcharias sp.
Rafinesque 1810
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Otero et al. 2014 | |||||||||
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Bivalvia
- Cardiida
- Cardiidae
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Cardium (Bucardium) acuticostatum
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Otero et al. 2014 | |||||||||
| original and current combination Bucardium | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Chile | State/province: | Biobio |
| Coordinates: | 36.6° South, 73.0° West (view map) | ||
| Paleocoordinates: | 38.6° South, 60.9° West | ||
| Basis of coordinate: | stated in text | ||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Late/Upper Cretaceous |
| Stage: | Maastrichtian | 10 m.y. bin: | Cretaceous 8 |
| Key time interval: | Late/Upper Maastrichtian | ||
| Age range of interval: | 72.10000 - 66.00000 m.y. ago |
Stratigraphy
| Formation: | Quiriquina | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: The sediments exposed along the coast north and south of Cocholgüe are Maastrichtian to Paleogene in age and include complete and well-exposed sections of the Quiriquina Formation (Biró-Bagóczky, 1982; Stinnesbeck, 1986). Cocholgüe was designated a paratype locality of the Quiriquina Formation by Biró-Bagóczky (1982)...The Quiriquina Formation was initially considered to be Campanian–Maastrichtian in age based on abundant and diverse ammonoids and bivalves (e.g., Biró-Bagóczky, 1982), but subsequent revisions of the ammonoid assemblage refined the age to Maastrichtian (Stinnesbeck, 1986) and then to upper Maastrichtian (Stinnesbeck, 1996; Salazar et al., 2010; Stinnesbeck et al., 2012)...The holotype specimen was found in upper levels of the formation, around 5 m below the contact with the overlying Curanilahue Formation (Eocene), being the youngest occurrence of a plesiosaurian in the unit | |||||
Lithology and environment
| Primary lithology: | bioturbation,concretionary,glauconitic sandstone |
| Secondary lithology: | "cross stratification",yellow calcareous sandstone |
| Includes fossils? | Y |
| Lithology description: The upper levels comprise bioturbated glauconitic sandstone and siltstone with sandy calcareous concretions that reach a thickness of 45 m "The unit is comprised by a basal fossiliferous microconglomerate and cross-bedded yellow sandstone, directly overlying a paleocliff of Paleozoic slates. The basal transgressive sand and conglomerate horizon is between 1.5 and 2 m thick and contains marine invertebrates. The upper levels comprise bioturbated glauconitic sandstone and siltstone with sandy calcareous concretions that reach a thickness of 45 m (Fig. 2). The fossil-bearing level is placed in the upper portion of the unit, about 5 m below the erosive contact with the Curanilahue Formation of Eocene age." | |
| Environment: | marine indet. |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | good |
| Fragmentation: | occasional |
| Spatial resolution: | parautochthonous |
Collection methods and comments
| Collection methods: | surface (float),surface (in situ),field collection | ||
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | M. E. Suarez | Collection dates: | 2001– |
| Collection method comments: The present specimen was recovered in two excavations at the beach near Cocholgüe. In 2001, one of the authors (M.E.S.) collected a partial skull, mandibular fragments, and twelve anterior cervical vertebrae that were exposed in the intertidal zone. The anterior portion was already lost due to erosion. This material was later described by Suárez and Fritis (2002) and referred to the genus Aristonectes. Species-level identification was precluded at that time due to the lack of preparation. A second excavation was independently executed at the same site in early 2009 and was carried out by a team of the
Universidad de Concepción (Chile) and the Institut für Geowissenschaften, Universität Heidelberg (Germany). This excavation recovered 119 blocks of sandstone, most of them with bony material, some damaged due the degradation of the bones by periodic seawater immersion that turned the more delicate portions into brittle surfaces. Also, several contacts were lost as sandstone blocks were cut out of the beach with a rock saw at low tide. The precise location of both excavations (skull in 2001 and postcranial skeleton in 2009) was identified during 2009 by two of the authors (R.A.O., D.R.R.), confirming that they were recovered from the same stratigraphic layer and separated by a distance of only 1.5 m. The taphonomic distribution of bones was consistent in the two excavations, indicating a north-south directed dispersal pattern of the skeleton (Fig. 2), with the skull and anterior vertebrae directed to the south and the trunk to the north. Bones recovered in each excavation are anatomically complementary, also indicating that they result from a single skeleton, and despite intensive searches on site no other vertebrate remains were observed, further suggesting that both excavations produced material from a single individual. Finally, measurements of the cervical centra (including correlated VLI indexes sensu Brown, 1981; O'Keefe and Hiller, 2006), and taphonomic features such as a similar pattern of distortion with cervical vertebrae crushed to the right side, are also consistent with a single individual | |||
Metadata
| Database number: | 150921 | ||
| Authorizer: | R. Benson, M. Uhen, M. Carrano | Enterer: | R. Benson, M. Carrano, N. Brand |
| Modifier: | F. Aspromonte | Research group: | vertebrate |
| Created: | 2013-09-17 17:19:47 | Last modified: | 2024-01-09 11:09:38 |
| Access level: | the public | Released: | 2013-09-17 17:19:47 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 48213. | M. E. Suarez and O. Fritis. 2002. Nuevo registro de Aristonectes sp. (Plesiosauroidea incertae sedis) del Cretácico Tardío de la Formación Quiriquina, Cocholgüe, Chile. Boletín de la Sociedad de Biología de Concepción 73:87-93 [R. Benson/R. Benson] |
Secondary references:
| 73986 | P. Jiménez-Huidobro, R. A. Otero, S. Soto-Acuña and M. W. Caldwell. 2019. Reassessment of cf. Plotosaurus from the upper Maastrichtian of Chile, with comments on the South American distribution of halisaurine mosasaurs. Cretaceous Research 103:104162:1-9 [M. Uhen/N. Brand/P. Mannion] | |
| 87135 | R. A. Otero. 2024. Reappraisal of the first historical record of Aristonectes Cabrera, 1941 (Elasmosauridae, Aristonectinae) from the Upper Cretaceous of central Chile. Cretaceous Research 156:105797:1-12 [E. Vlachos/F. Aspromonte/P. Mannion] | |
| 85609 | R. A. Otero, J. P. O'Gorman, and N. Hiller. 2015. Reassessment of the upper Maastrichtian material from Chile referred to Mauisaurus Hector, 1874 (Plesiosauroidea: Elasmosauridae) and the taxonomical value of the hemispherical propodial head among austral elasmosaurids. New Zealand Journal of Geology and Geophysics 58(3):252-261 [P. Mannion/P. Mannion] | |
| 48755 | R. A. Otero, S. Soto-Acuña, F. R. O'Keefe, J. P. O'Gorman, W. Stinnesbeck, M. E. Suárez, D. Rubilar-Rogers, C. Salazar, and L. A. Quinzio-Sinn. 2014. Aristonectes quiriquinensis sp. nov., a new highly derived elasmosaurid from the upper Maastrichtian of central Chile. Journal of Vertebrate Paleontology 34(1):100-125 [R. Benson/R. Benson/R. Benson] | |
| 77281 | R. A. Otero, S. Soto-Acuña, and D. Rubilar-Rogers. 2015. El registro fósil de plesiosaurios (Sauropterigia) en Chile. Publicación Ocasional del Museo Nacional de Historia Natural, Chile 63:151-188 [M. Uhen/M. Uhen] | |
| 50610 | J. F. Parham, R. A. Otero, and M. E. Suárez. 2014. A sea turtle skull from the Cretaceous of Chile with comments on the taxonomy and biogeography of Euclastes (formerly Osteopygis). Cretaceous Research 49:181-189 [P. Mannion/J. Tennant/M. Carrano] |