La Esquina, Ischigualasto (MACN-UPLR) (Triassic of Argentina)

Where: La Rioja, Argentina (30.0° S, 68.1° W: paleocoordinates 39.2° S, 31.6° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Los Colorados Formation (Agua de la Peña Group), Norian (228.0 - 208.5 Ma)

• upper part of formation; formation is considered to be latest Triassic in age

• bed-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; red siliciclastic sediments

• "The sequence was interpreted as deposited by moderately sinuous fluvial systems, which laterally interfinger with and grade into horizontally bedded flood-plain deposits. To the top of the sequence, thin-bedded sandstones and siltstones dominate and were deposited in ponds and as crevasse splays in overbank settings" (Arcucci et al. 2004)
• "The red beds of Los Colorados Formation are composed by successive thinning-upward cycles characterized by coarse- to medium-grained sandstones and fine-grained sandstones intercalated with siltstones, which progressively dominate to the upper part of the unit (Fig. 2). Coarse-grained sandstone beds are generally tabular in geometry, cross stratified (large-scale trough and tabular cross-bedding) and locally display horizontal lamination. Rounded pebbles and cobbles of chert, quartzite and metamorphic rocks commonly mantle set boundaries. Massive and horizontal laminated siltstones interfinger with rippled lamination fine-grained sandstones forms the uppermost portion of the cycles" (Arcucci et al. 2004)

Size class: macrofossils

Collected in 1986; reposited in the MACN

Collection methods: quarrying, mechanical,

Primary reference: J. F. Bonaparte and J. A. Pumares. 1995. Notas sobre el primer craneo de Riojasaurus incertus (Dinosauria, Prosauropoda, Melanorosauridae) del Triasico Superior de La Rioja, Argentina [Notes on the first skull and jaws of Riojasaurus incertus (Dinosauria, Prosauropoda, Melanorosauridae), Late Triassic of La Rioja, Argentina]. Ameghiniana 32(4):341-349 [M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 58569: authorized by Matthew Carrano, entered by Matthew Carrano on 14.02.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Saurischia - Riojasauridae
Riojasaurus incertus Bonaparte 1969 sauropodomorph
ULF/UPLR 56