The Palaeozoic succession of Spiti, located in the northwestern Himalayas of India, represents one of the most complete and well-preserved sequences of early Paleozoic rocks in the Indian subcontinent. This succession provides critical insights into the sedimentary environments, faunal evolution, and tectonic history of the region during the Palaeozoic era. The stratigraphy of Spiti is characterized by a well-defined sequence of sedimentary rocks ranging from the Cambrian to the Permian, with clear lithological, paleontological, and structural records. The Cambrian sequence in Spiti is marked by the presence of the Lipak Formation, predominantly consisting of quartzites, dolomitic limestones, and phyllites. These rocks indicate a shallow marine depositional environment with periodic episodes of deeper water conditions. Trilobites are the most significant fossils in this sequence, which not only help