Paraje La Esquina (Triassic of Argentina)

Also known as Lessemsaurus type site

Where: La Rioja, Argentina (30.4° S, 66.1° W: paleocoordinates 40.6° S, 29.9° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

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

• upper part of formation, Upper Norian, Coloradian Reptile Age; "same levels" as most other fossils in this unit from the same area; 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 by Bonaparte, Vince, Loyal & Fasola in 1971

Collection methods: quarrying, mechanical,

• collected by J. F. Bonaparte, M. Vince, J. C. Loyal and T. H. Fasola (CONICET)

Primary reference: J. F. Bonaparte. 1999. Evolución de las vértebras presacras en Sauropodomorpha [Evolution of the presacral vertebrae in Sauropodomorpha]. Ameghiniana 36(2):115-187 [M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 56156: authorized by Matthew Carrano, entered by Matthew Carrano on 14.11.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Reptilia
 Saurischia - Lessemsauridae
Lessemsaurus sauropoides n. gen. n. sp.
Lessemsaurus sauropoides n. gen. n. sp. Bonaparte 1999 sauropod