Head of Los Tarros river, kilometer 128 (Triassic of Argentina)

Where: La Rioja, Argentina (30.0° S, 67.9° W: paleocoordinates 39.1° S, 31.4° W)

• coordinate estimated from map

• small collection-level geographic resolution

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

• "upper levels" of the 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

Collection methods: PVL: Palaeontologia de Vertebrados, Instituto Miguel Lillo, Tucuman, Argentina

Primary reference: J. B. Desojo and A. M. Baez. 2005. El esqueleto postcraneano de Neoaetosauroides (Archosauria: Aetosauria) del Triásico Superior del centro-oeste de Argentina. Ameghiniana 42:115-126 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 105697: authorized by Richard Butler, entered by Richard Butler on 24.02.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Reptilia
 Archosauria -
Archosauria indet.
Archosauria indet. Cope 1869 archosaur
 Pseudosuchia - Stagonolepididae
Neoaetosauroides engaeus
Neoaetosauroides engaeus Bonaparte 1969 aetosaur
PVL 3665, postcrania
 Saurischia -
Sauropodomorpha indet.
Sauropodomorpha indet. Huene 1932 sauropodomorph