The sandstones, mudstones, conglomerates and tuffs of the formation were deposited in an fluvial (river-dominated) floodplain environment, characterized by cool temperatures and strongly seasonal rainfall.

The formation is most well-studied in Ischigualasto Provincial Park, a protected area established in San Juan Province in 1967 and designated a UNESCO World Heritage Site in 2000.

The name Ischigualasto is derived from the extinct Cacán language, spoken by an indigenous group referred to as the Diaguita by the Spanish conquistadors and means "place where the moon alights".

The Ischigualasto Formation is found in the Ischigualasto-Villa Unión Basin, along the border between La Rioja and San Juan Provinces, in the badlands of Western Argentina.

Type B paleosols have high proportions of smectite and mica, frequent slickensides, wedge-shaped crevices (mudcracks in cross-section), and strong redoximorphic features such as gleying and mottling.

[11] Type D paleosols have high smectite and kaolinite, fine mottling, and distinctively numerous hematite nodules and clay films (argillic horizons).

[11] Type E paleosols are simple blocky soils packed with calcareous structures and a distinct carbonate horizon alongside smectite and mica.

[12] A major faunal turnover and loss of diversity occurs in the early part of the Valle de la Luna Member, shortly before the start of the Norian.

[3] Small stratigraphic gaps may have been present at Cerro Las Lajas, lending some uncertainty to the thickness of the exposure and the precise level of the tuff beds.

[5][16] Likewise, sediments of the Los Rastros Formation may have been superseded later in Cerro Las Lajas relative to Ischigualasto Provincial Park.

[21][22][23] Langer (2005) reestablished the term "Ischigualastian" for this shared faunal zone in South America, based on Bonaparte (1966)'s characterization of the Ischigualasto Formation as an interval with unique fossils.

The Land Vertebrate Faunachron (LVF) system, initiated by Lucas (1998), intends to correlate Triassic formations on a global scale via tetrapod biostratigraphy.

Lucas placed the Ischigualasto Formation within the Adamanian LVF, an biozone defined primarily by species and assemblages in southwest North America.

[30] Lucas's conception of Stagonolepis is unconventionally broad, lumping together not just the original European fossils, but also Aetosauroides[31][32] and the North American genus Calyptosuchus, in defiance of many other specialists.

[38] Fossils from the "Isalo II" beds of Madagascar are broadly comparable to the Ischigualasto Formation, and the native Madagascan rhynchosaur, Isalorhynchus, has occasionally been considered a species of Hyperodapedon.

[39] The Ischigualasto Formation dates to only a few million years after the Carnian Pluvial Episode (CPE), an interval of particularly warm and wet global climate in the mid-Carnian.

[11] A 2008 study compared the distribution of paleosols and plant fossils, with implications for climate change and the evolution of depositional environments within the Ischigualasto Formation.

[44] The La Peña Member would have been subhumid and frequently destabilized by shifting braided rivers, leaving little room for the development of dry mature soils or forests.

[44] By time of the Cancha de Bochas Member, the river systems stabilized into meandering and anastomosing forms, but the climate became much drier, so plant growth continued to be inhibited.

[44] The upper Valle de la Luna Member was by far the wettest part of the formation, with a mean annual precipitation exceeding 760 millimeters per year (30 in/year).

A high water table, stable river channels, and a more humid climate allowed for the development of marsh habitats, widespread deep soils, and large trees.

[44] Dry conditions returned with the Quebrada de la Sal Member, with small sandy streams as the predominant depositional environment.

These fluctuations are difficult to compare with changes in the fauna and flora, though rhynchosaur abundance and pseudosuchian diversity may show a positive correlation with high humidity in the formation.

There is little consistency in the distribution of particular animal groups relative to their place of burial, though well-preserved skulls of small cynodonts are unusually common in channel sandstone.

[46][47] For example, branches of Rhexoxylon piatnitzkyi were tunneled by wood-boring beetles (surprisingly similar to modern cerambycids) and decayed by white rot fungi.

[50][51] The other tunnel morphotype is a calcareous web of narrow, elliptical burrows (average diameters of 7 cm) branching out from a long vertical shaft.

[51] A 1993 study found dinosaur specimens to comprise only 6% of the total tetrapod sample;[10] subsequent discoveries increased this number to approximately 11% of all findings by 2011.

The second group is the Onslow province, a subtropical palynoflora (30-40° S) which is found further north in areas closer to the Tethys Sea, equivalent to India, Madagascar, East Africa, and northern Australia.

It helps to support the idea that the Onslow province rings around the middle latitudes of the entire Southern Hemisphere, rather than just the vicinity of the Tethys Sea.

The distinction between the Ipswich and Onslow palynofloras may be based on local environmental conditions (such as the availability of riparian or upland habitats) rather than regional climate.