Puerto Arazatí (Camacho Fm): Late Miocene, Uruguay

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Panameriungulata - Proterotheriidae
Proterotheriidae indet. Ameghino 1887
Corona et al. 2020
MNHN 2966
Pseudobrachytherium breve n. gen., n. sp. Corona et al. 2020
Corona et al. 2020
Holotype: FC-DPV 2570
Neobrachytherium cf. ameghinoi Soria 2001
Corona et al. 2020
MNHN 2967
Mammalia - Carnivora - Procyonidae
Cyonasua sp. Ameghino 1885
MNHN 2965
see common names

Geography
Country:Uruguay State/province:San José
Coordinates: 34.6° South, 57.0° West (view map)
Paleocoordinates:34.6° South, 54.8° West
Basis of coordinate:stated in text
Altitude:0 meters
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Miocene
10 m.y. bin: Cenozoic 6
Key time interval: Late Miocene Mammal zone:  Huayquerian
Age range of interval: 11.63 - 5.333 m.y. ago
Stratigraphy
Formation:Camacho Member:San Pedro
Stratigraphic resolution:member
Stratigraphy comments: Soibelzon et al. 2019: The lithostratigraphic units recognized from base to top are the Camacho (late Miocene), Raigón (Pliocene and Pleistocene) and Libertad (Pleistocene) formations (Bossi and Navarro, 1991; McDonald and Perea, 2002; Bossi et al., 2009; Tófalo et al., 2009; Perea et al., 2013). The first two units yield many vertebrate fossils, including a variety of cingulates, ground sloths, rodents and notoungulates (Vizcaíno et al., 2003; Rinderknecht et al., 2011, 2018; Perea et al., 2013). The remains described here were found in levels of the Camacho Formation (Fig. 2). This unit in Uruguay represents an extended late Miocene highstand eustatic event regionally known as the Paranean transgression or Paranean Sea (Sprechmann et al., 2000).

Corona et al 2020: The Camacho Formation (Goso and Bossi, 1966) outcrops in the Southwest of Uruguay (Departments of Colonia and San José). It constitutes marine deposits of the Neogene of Uruguay and its transition to continental areas. The Camacho Formation is constituted by sandstones from very fine to coarse, limolites and clay pelites, with a maximum thickness in outcrops of about 15 meters (Perea et al., 2013). Two lithostratigraphic members are recognized within this unit (Martínez, 1994; Perea and Martínez, 2004): the lower one, the San Pedro Member is the most widespread and covers the Departments of Colonia and San José; it is characterized by the dominance of sandy-silt and bioturbated silty deposits of predominantly gray-greenish color. The greatest diversity of mammals in the unit occurs in this member, particularly in paralic facies (Perea et al., 2013, 2019, 2020).
The upper Member, Cerro Bautista, stands out for its fine to very fine white sandstones, along with levels composed of coarser fractions. It is the most geographic restricted member (Colonia Department) and is also the less fossiliferous. The Cerro Bautista Member includes internal shelf deposits very close to the coast, with shallow waters, channels and estuarine plains, very proximal storms, intertidal and beach deposits.
The Camacho Formation represents the deposits of several sub-environments of the “Mar Entrerriense” or “Paranean Sea” shelf, including organisms with requirements of warm waters and normal-marine salinity. Foraminifera, ostracods, gastropods, bivalves, brachiopods, echinoderms, crustaceans, bryozoans, chondricthyes, dolphins and whales and also many continental vertebrates are abundant, as ichnofossils as well (Sprechmann et al., 2000; Perea and Martínez, 2004; Verde and Perea, 2011; Perea et al., 2013, 2019, 2020). The invertebrate associations are autochtonous-parautochtonous and as mentioned above, mammals are especially represented in coastal facies of the San Pedro Member.
With regard to age, the assignment of the Camacho Formation to the Late Miocene is supported by a whole of independent sources. The mammals integrated to the Assemblage biozone of Pseudoplohophorus absolutus (according to Perea et al., 1994, 1996, 2020; Perea, 2005) have affinities with the Huayquerian Age/Stage (sensu Cione and Tonni, 1995) of the Late Miocene, typified in strata of Argentina (Marshall and Cifelli, 1991). Many of the mammalian taxa are exclusive of the Camacho Formation and the Ituzaingó Formation (Late Miocene) of Argentina (Perea et al., 2013, 2020). On the other hand, the evidence obtained from the mollusk associations supports a similar chronostratigraphic interpretation for the Camacho Formation; their associations have a close relationship with those from the Paraná and Puerto Madryn formations of Argentina (Martínez, 1994; del Río and Martínez, 1998; Martínez and del Río, 2002a, b). Numerical ages based on strontium isotopes (87Sr/86Sr) were obtained for shells of Aequipecten paranensis d'Orbigny, 1842 from the Puerto Madryn Formation (11.9–9.05 Ma) and Camacho Formation (7.50–6.00 Ma), that encompass the “Paranense” flooding, including transgressive and regressive phases (del Río et al., 2018). Soibelzon et al. (2019) suggested two intervals for the unit, 15–13 Ma and 11–9 Ma, based on ostreids
Lithology and environment
Primary lithology:fine,gray,green,yellow silty claystone
Includes fossils?Y
Lithology description: Soibelzon et al. 2019: The sediments of the Camacho Formation are formed by greenish-grey friable claystones and mudstones that become greenish- brownish and slightly coarser toward the top.
Environment:terrestrial indet.
Geology comments: Soibelzon et al. 2019: This unit in Uruguay represents an extended late Miocene highstand eustatic event regionally known as the Paranean transgression or Paranean Sea (Sprechmann et al., 2000). In the San José Department, this includes facies related to a regressive phase, characterizing a shallow marine environment on a siliciclastic shelf.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collection method comments: Soibelzon et al. 2019: MNHN 2965 housed in Museo Nacional de Historia Natural, Montevideo, Uruguay
Metadata
Also known as:Arazatí harbor
Database number:202701
Authorizer:P. Mannion Enterer:G. Varnham, M. Kouvari
Modifier:M. Kouvari Research group:vertebrate
Created:2019-07-18 13:00:48 Last modified:2020-05-21 04:24:50
Access level:the public Released:2019-07-18 13:00:48
Creative Commons license:CC BY
Reference information

Primary reference:
69334. L. H. Soibelzon, A. Rinderknecht, J. Tarquini and R. Ugalde. 2019. First record of fossil procyonid (Mammalia, Carnivora) from Uruguay. Journal of South American Earth Sciences 92:368-373 [P. Mannion/G. Varnham]

Secondary references:

72446 A. Corona, A. C. Badin, D. Perea, M. Ubilla, and G. I. Schmidt. 2020. A new genus and species and additional reports of the native South American ungulates Proterotheriidae (Mammalia, Litopterna) in the Late Miocene of Uruguay. Journal of South American Earth Sciences [P. Mannion/M. Kouvari]