Chucal: Santacrucian, Chile

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
Chinchillinae indet.
sp. 1 & 2
Mammalia - Cingulata - Chlamyphoridae
Stenotatus sp. Ameghino 1891
New species?
Mammalia - Cingulata - Glyptodontidae
Parapropalaehoplophorus septentrionalis n. gen., n. sp. Croft et al. 2007
Mammalia - Cingulata
cf. Peltephilus sp. Ameghino 1887
Mammalia - Notoungulata
Hegetotherium cf. mirabile Ameghino 1887
(19 measurements)
Mammalia - Notoungulata - Mesotheriidae
Eotypotherium chico Croft et al. 2004
(28 measurements)
Altitypotherium paucidens Croft et al. 2004
(39 measurements)
Altitypotherium chucalensis Croft et al. 2004
(68 measurements)
Mammalia - Notoungulata - Toxodontidae
Toxodontidae indet. Ameghino 1889
new taxon
Palyeidodon ? sp. Roth 1898
Bond and García 2002
Specimen ID: SNGM 946
Nesodon imbricatus Owen 1846
(9 measurements)
Adinotherium sp. Ameghino 1887
Mammalia - Panameriungulata - Macraucheniidae
Thesodon sp.
    = Theosodon sp. Ameghino 1887
Flynn et al. 2002
Mammalia - Rodentia - Chinchillidae
Miochinchilla surirense n. gen., n. sp. Croft et al. 2021
Croft et al. 2021
Holotype: SGOPV 4118, partial cranium; SGOPV 4140; SGOPV 4082; SGOPV 4092; SGOPV 4138; SGOPV 4079; SGOPV 4094; SGOPV 5060; SGOPV 5195; SGOPV 5061; SGOPV 4148; SGOPV 4073, SGOPV 4080, SGOPV 4088, 4090, SGOPV 4093, SGOPV 4131, SGOPV 4132, SGOPV 4134, SGOPV 4141, SGOPV 4143, SGOPV 4149, SGOPV 4203, SGOPV 5062 to 5069, SGOPV 5145, SGOPV 5153, SGOPV 5167, SGOPV 5181, SGOPV 5185 to 5191, SGOPV 5196 to 5206, SGOPV 5208 to 5216, SGOPV 5218 to 5221
Mammalia - Rodentia
Octodontoidea indet. Waterhouse 1839
Acarechimys sp. Patterson 1965
Neoreomys sp. Ameghino 1887
Mammalia - Paucituberculata - Pichipilidae
? Pichipilinae indet. (Marshall 1980)
original and current combination Pichipilidae
Amphibia - Temnospondyli
Anura indet. (Fischer von Waldheim 1813)
see common names

Geography
Country:Chile
Coordinates: 18.5° South, 69.2° West (view map)
Paleocoordinates:19.2° South, 65.1° West
Basis of coordinate:stated in text
Altitude:4200 meters
Geographic resolution:outcrop
Time
Period:Neogene Epoch:Miocene
Stage:Burdigalian 10 m.y. bin:Cenozoic 5
Key time interval:Santacrucian
Age range of interval:17.50000 - 16.30000 m.y. ago
Age estimate:18.79 ± .11 Ma (Ar/Ar)21.7 ± .8 Ma (K-Ar) to 17.5 ± .4 Ma (Ar/Ar)
Stratigraphy
Formation:Chucal
Stratigraphic resolution:formation
Stratigraphy comments: late early Miocene Santacrucian South American Land Mammal ‘Age’ (SALMA)
Bond and García, 2002: Palyeidodon? sp. found in the upper layers of the Chucal formation; the fossil material is assigned Colloncuran in age but lies beneath strata radiometrically dated to 17-16Ma (Santacrucian).

Townsend and Croft 2010: 17.4 ± 0.4 Ma to 21.7 and 21.7 ± 0.8 Ma
Lithology and environment
Primary lithology: sandstone
Lithology description: The Chucal Fauna derives primarily from the Chucal Formation, a 600 m thick sequence of variegated fluvo-lacustrine strata in the Chilean Altiplano The base of this suc- cession consists of a channelized conglomerate followed by upward fining sandstones, siltstones, and mudstones with limestone intercalations (200 m). A coarse- to fine-grained, massive, greenish sandstone succession (containing calcare- ous mudstones, limestone, and tuff intercalations) overlies these deposits (225 m). The upper portion of the Chucal Formation consists of gray mudstones followed by cross- bedded sandstones and minor conglomeratic intercalations (172 m). The described succession reflects the following inferred environmental evolution: (1) fluvial or distal alluvial conditions grading to fluctuating lacustrine conditions ending in a well-developed lacustrine environment; (2) a stage of increased transport energy evidenced by the succession of green sandstones that filled the lake and expanded the fluvial plain environment; and (3) flood plain development grading to fluvial plain conditions. This evolution indicates two stages of basin development, one prior to deposition of the green sandstone succession and one after its deposition. Most of the Chucal fossils described in this work derive from the intermediate, green sandstone-bearing interval of the western flank (Member W3 of Charrier et al. 2005).
Environment:"floodplain"
Geology comments: Paleobotanical evidence suggests that the area was located at an altitude of ca. 1000 m when the formation was deposited
Bond and García, 2002: Fine grained, calcareous sedimentary rocks and volcanic rocks.
fluvial and lacustrine strata deposited in a rather narrow, approximately north–south running intermontane basin
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:general faunal/floral analysis
Metadata
Database number:103804
Authorizer:M. Uhen, C. Jaramillo, P. Mannion Enterer:M. Shalap, G. Varnham, J. Carrillo, M. Uhen
Modifier:G. Varnham Research group:vertebrate
Created:2011-02-02 09:18:35 Last modified:2022-05-23 04:04:09
Access level:the public Released:2011-02-02 09:18:35
Creative Commons license:CC BY
Reference information

Primary reference:

34887. D. A. Croft, J. J. Flynn, and A. R. Wyss. 2007. A New Basal Glyptodontid and other Xenarthra of the Early Miocene Chucal Fauna, Northern Chile. Journal of Vertebrate Paleontology 27(4):781-797 [M. Uhen/M. Shalap]

Secondary references:

69078 M. Bond and M. García. 2002. Nuevos restos de toxodonte (Mamalia, Notoungulata) en estratos de la Formación Chucal, Mioceno, Altiplano de Arica, norte de Chile. Revista Geológica de Chile 29(1):81-91 [P. Mannion/G. Varnham]
81729 D. A. Croft, J. J. Flynn, A. R. Wyss, R. Charrier, and F. Anaya. 2021. New Chinchillid Rodents (Hystricognathi: Caviomorpha) from Northern Chile and Bolivia Fill a 17‐Million‐Year Gap in the Pan‐Chinchilline Fossil Record. Journal of Mammalian Evolution 28:1205-1236 [P. Mannion/G. Varnham]
44887 J. J. Flynn, D. A. Croft, R. Charrier, G. Herail, and A.R. Wyss. 2002. The first Cenozoic Mammal Fauna from the Chilean Altiplano. Journal of Vertebrate Paleontology 22(1):200-206 [C. Jaramillo/J. Carrillo]
69987 B. Townsend and D. A. Croft. 2010. Middle Miocene Mesotheriine diversity at Cerdas, Bolivia and a reconstruction of Plesiotypotherium minus. Palaeontologia Electronica 13(1):1A [P. Mannion/M. Kouvari]