Las Hornillas bearing level (Miocene of Argentina)

Also known as LHBL

Where: San Juan, Argentina (32.0° S, 69.8° W: paleocoordinates 32.6° S, 65.2° W)

• coordinate stated in text

• small collection-level geographic resolution

When: TC3 Member (Chinches Formation), Santacrucian (17.5 - 16.3 Ma)

• This is a level coming from the lowest third of the Chinches Formation

•(Manantiales basin).

•The Tertiary sequences in the Manantiales basin represented by the Chinches Formation, have been divided into seven members (TC0 to TC6), and their integration allowed a reconstruction of the development over the whole Manantiales basin (Pérez 2001a) (Fig. 2).

•The Las Hornillas bearing level corresponds to TC3.

• group of beds-level stratigraphic resolution

Environment/lithology: fluvial; massive, lenticular, coarse-grained, conglomeratic sandstone

• These levels represent fluvial meandering environments whose energy diminishes upward in the section (Pérez 2001a).
• TC2 to TC4 are characterized by medium to coarse-grained, massive, parallel-stratified sandstones interfingered with lenticular conglomerates (Figs. 1b and 2). Clast composition mainly consists in rhyolites and volcanic breccia derived from the Choiyoi Group. Shales interfinger toward the top (TC4).

Size classes: macrofossils, mesofossils

Collected in 2005, 2007, 2008

Primary reference: G. M. López, M. G. Vucetich, A. A. Carlini, M. Bond, M. E. Pérez, M. R. Ciancio, D. J. Pérez, M. Arnal, and A. I. Olivares. 2011. New Miocene mammal assemblages from Neogene Manantiales basin, Cordillera Frontal, San Juan, Argentina. In J. A. Salfity, R. A. Marquillas (eds.), Cenozoic Geology of the Central Andes of Argentina 211-226 [P. Mannion/M. Kouvari]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 197900: authorized by Philip Mannion, entered by Miranta Kouvari on 28.11.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

• The main goal of this paper is to report these new mammal assemblages. Detailed anatomical and systematic studies of these mammals will be accomplished elsewhere.
Mammalia
 Paucituberculata - Palaeothentidae
Palaeothentes sp. Ameghino 1887 marsupial
 Notoungulata - Toxodontidae
"Nesodon conspurcatus" = Nesodon imbricatus
"Nesodon conspurcatus" = Nesodon imbricatus Owen 1846 notoungulate
 Notoungulata - Interatheriidae
Protypotherium "sp. 1" Ameghino 1882 notoungulate
Protypotherium "sp. 2" Ameghino 1882 notoungulate
 Notoungulata - Mesotheriidae
Mesotheriidae "gen. et sp. nov 2" Alston 1876 notoungulate
 Notoungulata - Hegetotheriidae
Pachyrukhinae indet. notoungulate
 Rodentia - Cephalomyidae
Cephalomyopsis ? sp. Vucetich 1985 caviomorph
 Rodentia -
Octodontoidea "gen. et sp. indet. 1" Waterhouse 1839 caviomorph
Octodontoidea "gen. et sp. indet. 2" Waterhouse 1839 caviomorph
"Ameghinomys constans" = Acarechimys constans Ameghino 1887 caviomorph
Eocardia excavata Ameghino 1891 caviomorph
Eocardia montana Ameghino 1887 caviomorph
 Rodentia - Chinchillidae
Prolagostomus sp. Ameghino 1887 chinchilid
 Panameriungulata - Macraucheniidae
Macraucheniidae indet. Ameghino 1889 placental
 Megatherioidea - Megatheriidae
"Prepotheridae indet." = Prepotherinae
"Prepotheridae indet." = Prepotherinae Ameghino 1894 edentate
In text : Prepotheriidae indet.
 Cingulata - Chlamyphoridae
Prozaedyus sp. Ameghino 1891 edentate