La Boca Formation is genetically related to the
Nazas volcanic Arc of the same age (Pliensbachian-Aalenian, ~189.5–171.6 Ma), which was created when Mexico evolved in a convergent plate margin, with the
Gulf of Mexico remaining as a restricted basin and a passive margin. The influence of this arc is seen on the continental units such as
Todos Santos Formation, which deposited volcanic materials in both nonmarine strata and marginal marine red beds of eastern Mexico. La Boca Formation left its sediments on a basin formed between the
Nazas Volcanic Arc center and the so-called
Huizachal-Peregrina Anticlinorium, giving the basin layers whose origin is linked with braided river deposits with different flooding levels, channels fills, and channel belts filling valleys. All data trends suggest a highly unusual debris-flow environment in which local fluvial alluvial bodies were not big enough to sustain large freshwater biota such as fishes, and most of the preserved specimens were fast-buried near the place of death. == Fossil record ==