Dinosaur Footprints in Terrigenous Sediments on the Early Jurassic Shelf of the Central North Caucasus: Sedimentological and Paleoecological Settings

Dinosaur footprints were found in Pliensbachian terrigenous rocks in the central North Caucasus. Tracks of different sizes (12‒35 cm) were identified at three levels of the Mizur Formation section. The sediments accumulated on the wide (15‒20 km) shelf of a paleobasin. The coastal land was covered with abundant vegetation. The warm and humid climate favored the development of weathering crusts, lake–bog systems, and peat accumulation. The seawater temperature ranged from 21 to 25°C. The accumulation of sediments on the shallow shelf and their distribution over the area were influenced by wave activity, currents, and tidal phenomena. At low tide, small dinosaurs visited the shelf zone in order to search for food in the form of benthic fauna, which was abundant in clayey–silty sediments. The simultaneous presence of significantly different–size animal tracks may indicate that large individuals preyed on smaller ones. The presence of dinosaur tracks at different levels of the upper Pliensbachian strata indicates that representatives of the terrestrial fauna periodically visited the paleoshelf during the Domerian.