Early Cambrian <i>Thalassinoides</i> From the Mussoorie Syncline, Lesser Himalaya (India): Paleoecological, Paleoenvironmental and Biostratigraphic Significance

ABSTRACT We report densely packed and multiple‐layered Thalassinoides burrows network from the Calcareous Member (Deo‐Ka‐Tibba Formation, Tal Group) Mussoorie syncline documenting complex and high‐density bioturbation in the Early Cambrian (Stage 4) shallow‐marine environment. The Thalassinoides record from the Mussoorie syncline documents distinct colonisation windows along the northern Indian margin that are comparable to those of South China, implying similar trace‐maker densities and an Early Cambrian palaeobiogeographic extension of this ichnogenus in tidal‐flat setting. This member is unconformably overlain by the siliciclastic‐rich Dhaulagiri Formation, reflecting high‐energy deposition with terrigenous influx. The stratigraphic correlation of the Calcareous Member supports a Cambrian (Stage 4) age, invalidating the earlier Stage 3 assignment. This discovery adds a distinctive ichnogenus to those already well known from Himalayan Cambrian rocks.