The conglomerates, sandstones and mudstones of the 560 m (1,840 ft) thick formation were deposited in terrestrial lacustrine, alluvial, fluvial and deltaic environments.

The lake sediments of the Lagerstätte provided fossil cartilaginous fishes and their egg capsules and unusual Triassic reptiles like Sharovipteryx and Longisquama.

[6] The Middle-Late Triassic layers rest on top of Paleozoic basement with local Permo-Triassic molasse sediments.

[7][4] The formation consists of a wide and multicolored variety of siliciclastic rocks: mudstones, sandstones, conglomerates, fanglomerates, and rare coal layers.

This diversity of sediment types reflects the a complex set of depositional environments through time and space, including alluvial fans, sandflats, swamps, back-swamp areas, and littoral to profundal lake zones.

[8] Isotope analyses of fish teeth confirm that the lakes and rivers represented by the formation were entirely freshwater and deep inland, about 600 km from the nearest coast.

The abundance of burrows and absence of darker sediments in this area indicate that it was a well-oxygenated lacustrine environment, such as a large oxbow lake.

[6] During the 1960s, Russian paleontologists recovered an unusually rich fossil content in the type strata of the Madygen Formation, including abundant macrophytes, more than 20,000 insect remains[11] and unique small reptiles with well preserved soft tissue.

[8] Spirorbis-like polychaete worm tubes, crustaceans (ostracods, kazacharthrans, conchostracans, malacostraca), freshwater Bivalves and gastropods are known from shallow to deeper lake environments.

Non-aquatic insects are among the most common fossil remains of the Madygen Formation, with half a thousand or so species having been uncovered from these sediments.

[9] Fish remains mostly represent endemic genera assigned to the actinopterygian families Evenkiidae (Oshia), Palaeoniscidae (Ferganiscus, Sixtelia) and Megaperleidus and Alvinia.

Tetrapods (and stem-tetrapods) are known from the mostly larval urodelan (Triassurus), a small procynosuchid cynodont (Madysaurus), a chroniosuchid reptiliomorph (Madygenerpeton), an early drepanosaurid reptile (Kyrgyzsaurus), a gliding archosauromorph (Sharovipteryx) and the enigmatic diapsid Longisquama.

The high amount of juvenile individuals found suggest the freshwater systems at the Madygen Formation served as a spawning grounds and nursery's for these prehistoric elasmobranchs.

[29] The Blattodea of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected), and some preserve details of the entire body.

[37] Like other large titanopterans, it was probably a poor flier which primarily used its wings to produce sounds or flashes of light for courtship of defensive purposes.

The Grylloblattodea and other basal polyneopterans of the Madygen Formation (sometimes described as Eoblattida or Protorthoptera, among other names) are very common (about 1500 specimens) and diverse (over 50 species).

[47] The Hemiptera of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected) and very diverse, though most remain undescribed.

[4][67] The Coleoptera of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected) and diverse (over 70 named species and many more undescribed).

[77] Apart from insects, the most common invertebrates found in the Madygen Formation are Almatium gusevi and Jeanrogerium sornayi, tadpole shrimp-like aquatic crustaceans in the order Kazacharthra.

[7] Among the oldest known root nodules have been found in the Madygen Formation, though the exact nature of the plant-microbe interaction responsible remains unknown.