Chucair Farm 2: Bartonian - Priabonian, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Mammalia - Cingulata - Dasypodidae
Isutaetus depictus Ameghino 1902
recombined as Pseudeutatus depictus
MJHG-NCP 261, one isolated osteoderm
Mammalia - Panameriungulata
Litopterna indet. Ameghino 1889
MJHG-NCP 256, isolated upper tooth
Mammalia - Panameriungulata - Adianthidae
Adianthidae informal n. genus
MJHG-NCP 257, left mandibular fragment with p3-m1
Mammalia - Notoungulata - Archaeohyracidae
Pseudhyrax eutrachytheroides Ameghino 1901
MJHG-NCP 4, two isolated upper premolars; MJHG-NCP 7, isolated right m3; MJHG-NCP 8, left maxillary fragment with P4-M1; MJHG-NCP 9, left mandibular fragment with p2; MJHG-NCP 255, probably associated left p3 or p4, and m1-m3; MJHG-NCP 258, right mandibular fragment with very worn p2-p4; MJHG-NCP 259, probably associated right p2-p4, m3, and left p1?; MJHG-NCP 260, right maxillary fragment with M1 or M2; MJHG-NCP 263, left premaxillary fragment with two incisors, left maxillary fragment with P1, two isolated upper molars, and one lower molar, and fragments (not associated); MJHG-NCP 271, right mandibular fragment with m1 and partial m2
Mammalia - Notoungulata
Eohegetotherium priscum Ameghino 1901
nomen vanum belonging to Eohegetotherium
MJHG-NCP 264, an isolated right upper molar
? Periphragnis circunflexus (Ameghino 1901)
MJHG-NCP 252, four associated lower cheek teeth, probably p3, p4, m1 and partial m2, one incisor-like lower tooth, a partial upper molar, and associated cranial and mandibular fragments
Mammalia - Notoungulata - Notohippidae
Puelia sigma (Ameghino 1901)
recombined as Acoelohyrax sigma
MJHG-NCP 2, associated left maxillary fragment with roots of P4, complete P3, M1-M3, right maxillary fragment with P1-P3, and three upper anterior teeth (I1, I2, and I3 or C1); MJHG-NCP 5, right mandibular fragment with m2-m3
Mammalia - Astrapotheria - Astrapotheriidae
cf. Astraponotus sp. Ameghino 1901
MJHG-NCP 269, probably associated upper and lower premolar
see common names

Geography
Country:Argentina State/province:Río Negro
Coordinates: 41.4° South, 69.7° West (view map)
Paleocoordinates:43.6° South, 60.7° West
Basis of coordinate:stated in text
Geographic resolution:small collection
Time
Period:Paleogene Epoch:Eocene
10 m.y. bin:Cenozoic 3
Key time interval:Bartonian - Priabonian
Age range of interval:41.20000 - 33.90000 m.y. ago
Stratigraphy
Formation:Las Chacras Member:Lower
Stratigraphic resolution:bed
Stratigraphy comments: The strong similarity with the Mustersan assemblage from the Rosado Member at Gran Barranca South of Colhué Huapi Lake, with a well constrained age of 38.16 – 37.4 Ma. (Dunn et al., 2013), suggests that the Lower Las Chacras Formation and its fauna is more likely of late Bartonian or early Priabonian age. Fossils come from 45 m above the base and 3 m below the major pyroclastic flow of the upper half of the measured section.
Lithology and environment
Primary lithology: conglomerate
Lithology description: Fine class-supported conglomerates with stacked whitish pyroclastic flow deposits. Paleosols exhibit weak horizonation, fine clayey rhizoliths and rhizohaloes, Fe-Mn nodules, mottles, blocky and granular peds, and solitary bee cells (Celliforma isp.)
Environment:fluvial indet.
Geology comments: Fluvial channel fills and larger pyroclastic flows on floodplain
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collection method comments: Collected by Rodolfo Casamiquela during 1940’s and 1950’s. Further collection by Kramarz et al. 2022 in October 2017 and April 2018
Metadata
Also known as:CH2
Database number:225623
Authorizer:P. Mannion Enterer:G. Varnham
Research group:vertebrate
Created:2022-05-20 07:32:30 Last modified:2022-05-20 07:32:30
Access level:the public Released:2022-05-20 07:32:30
Creative Commons license:CC BY
Reference information

Primary reference:
81725. A. Kramarz, E. Bellosi, M. Bond, A. M. Forasiepi, J. C. Fernicola, G. Aguirrezabala, and D. T. Rezende. 2022. Eocene mammals from volcaniclastic deposits of the Somun Cura Plateau: biostratigraphic implications for north Patagonia Paleogene. Andean Geology 49(2) [P. Mannion/G. Varnham/P. Mannion]