Bryn Gwyn (Sarmiento Fm): Colhuehuapian, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Testudines - Testudinidae
Chelonoidis cf. gringorum (Simpson 1942)
de la Fuente and Vucetich 1998
MPEF-PV 566, right humerus
Reptilia
Diogenornis sp. Alvarenga 1983
Agnolín and Cenizo 2014 1 specimen
MPEF-PV 1411)
    = ? Palaeospheniscus sp. Moreno and Mercerat 1891
Acosta Hospitaleche and Picasso 2022
Mammalia - Notoungulata
Hegetotherium novum n. sp. Bordas 1939
Kramarz and Paz 2013
badly preserved skull described by Bordas 1939
Hegetotheriopsis sulcatus n. gen., n. sp. Kramarz and Paz 2013
Kramarz and Paz 2013
Holotype: MACN Pv CH2015
Mammalia - Rodentia - Cephalomyidae
Cephalomyopsis hypselodontus
McGrath et al. 2023
Mammalia - Rodentia
Caviocricetus lucasi Vucetich and Verzi 1996
McGrath et al. 2023
Dudumus ruigomezi Arnal et al. 2014
McGrath et al. 2023
Mammalia - Rodentia - Acaremyidae
Galileomys antelucanus Vucetich and Kramarz 2003
McGrath et al. 2023
Acaremys preminutus Bordas 1939
McGrath et al. 2023
Mammalia - Rodentia
Protadelphomys latus Ameghino 1902
McGrath et al. 2023
Protacaremys prior Ameghino 1902
McGrath et al. 2023
Mammalia - Rodentia - Ctenomyidae
Willidewu esteparius Vucetich and Verzi 1991
McGrath et al. 2023
Mammalia - Rodentia
Prospaniomys sp. Ameghino 1902
Alvarez and Arnal 2015
MPEF-PV 5039 (see also Scasso and Bellosi 2004)
Prospaniomys priscus Ameghino 1902
McGrath et al. 2023
Mammalia - Rodentia - Erethizontidae
Hypsosteiromys axiculus (Ameghino 1902)
McGrath et al. 2023
Mammalia - Rodentia
Eosteiromys informal n. sp. Ameghino 1902
McGrath et al. 2023
Eosteiromys homogenidens Ameghino 1902
McGrath et al. 2023
Luantus informal n. sp. Ameghino 1899
McGrath et al. 2023
Luantus minor n. sp. Pérez et al. 2010
(4 measurements)
Mammalia - Rodentia - Dasyproctidae
Australoprocta fleaglei Kramarz 1998
McGrath et al. 2023
Mammalia - Rodentia
Soriamys gaimanensis Kramarz 2001
McGrath et al. 2023
Chubutomys leucoreios n. sp. Pérez et al. 2010
(4 measurements)
Mammalia - Rodentia - Chinchillidae
Eoviscaccia australis Vucetich 1989
McGrath et al. 2023
see common names

Geography
Country:Argentina State/province:Chubut
Coordinates: 43.3° South, 65.4° West (view map)
Paleocoordinates:43.9° South, 59.6° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Miocene
10 m.y. bin: Cenozoic 5
Key time interval: Colhuehuapian Mammal zone:  Colhuehuapian
Age range of interval: 20.9 - 17.4 m.y. ago
Stratigraphy
Formation:Sarmiento Member:Trelew
Stratigraphic resolution:member
Stratigraphy comments: Kramarz and Paz 2013: base of the Trelew Member of the Sarmiento Formation. All these deposits have been assigned to the Colhuehuapense Mammal Age (early Miocene) (Vucetich et al., 2010), although recently Kramarz et al. (2011) suggested that the mammal-bearing deposits of the Cerro Bandera Formation outcropping in the Barda Negra de Neuquén could be somewhat older than those of Bryn Gwyn and Paso Córdova
Lithology and environment
Primary lithology:paleosol/pedogenic,nodular "mixed carbonate-siliciclastic"
Lithology description: nodular calcrete deposit
Environment:terrestrial indet.
Taphonomy
Modes of preservation:body,replaced with phosphate
Size of fossils:macrofossils,mesofossils
Preservation of anatomical detail:good
Collection methods and comments
Collection methods:surface (in situ),field collection
Reason for describing collection:taxonomic analysis
Collection method comments: MEPF-PV (Museo Paleontológico Eigidio Feruglio- Paleontología de Vertebrados)
Metadata
Also known as:Loma Blanca
Database number:145897
Authorizer:C. Jaramillo, P. Mannion, J. Carrillo, E. Vlachos, M. Uhen Enterer:J. Carrillo, K. Pino, M. Uhen, E. Vlachos, M. Kouvari
Modifier:M. Kouvari
Created:2013-06-12 19:24:16 Last modified:2020-02-03 04:13:20
Access level:the public Released:2013-06-12 19:24:16
Creative Commons license:CC BY
Reference information

Primary reference:
47169. M. E. Pérez, M. G. Vucetich, and A. Kramarz. 2010. The first Eocardiidae (Rodentia) in the Colhuehuapian (Earky Miocene)of Bryn Gwyn (Northern Chubut, Argentina) and the early evolution of the peculiar cavioid rodents. Journal of Vertebrate Paleontology 30(2):528-534 [C. Jaramillo/J. Carrillo]

Secondary references:

87641 C. Acosta Hospitaleche and M. B. J. Picasso. 2022. About the alleged record of the Rheidae Diogenornis in the Cenozoic of Argentina: new interpretations. Historical Biology 35(9):1515-1521 [M. Uhen/M. Uhen]
87869 F. L. Agnolín and M. Cenizo. 2014. Nuevos registros de aves fósiles Argentinas y sus implicancias biogeográficas. Ameghiniana 51 (Suppl)(6):3-3 [M. Uhen/M. Uhen/M. Uhen]
70651 A. Alvarez and M. Arnal. 2015. First Approach to the Paleobiology of Extinct Prospaniomys (Rodentia, Hystricognathi, Octodontoidea) Through Head Muscle Reconstruction and the Study of Craniomandibular Shape Variation. Journal of Mammalian Evolution 22:519-533 [P. Mannion/M. Kouvari]
64145 M. S. de la Fuente and M. G. Vucetich. 1998. Nuevos materiales de tortugas cryptodiras miocenas del Valle de Chubut, Argentina. Ameghiniana 35(2):211-215 [E. Vlachos/E. Vlachos]
71662 A. G. Kramarz and E. R. Paz. 2013. Un Hegetotheriidae (Mammalia, Notoungulata) basal del Mioceno temprano de Patagonia Alejandro. Revista Mexicana de Ciencias Geológicas 30(1):186-195 [P. Mannion/M. Kouvari]
85330 A. J. McGrath, J. J. Flynn, D. A. Croft, J. Chick, H. E. Dodson and A. R. Wyss. 2023. Caviomorphs (Rodentia, Hystricognathi) from Pampa Castillo, Chile: new octodontoid records and biochronological implications. Papers in Palaeontology 9:e1477:1-32 [J. Carrillo/K. Pino/P. Mannion]