objects such as seals and standardised weights during the Kot Diji phase of this period. However, excavations at Harappa have demonstrated the development of some symbols from potter's marks and graffiti belonging to the earlier Ravi phase from . Mature Harappan In the Mature Harappan period, from about , strings of Indus signs are commonly found on flat, rectangular stamp seals as well as written or inscribed on a multitude of other objects including pottery, tools, tablets, and ornaments. Signs were written using a variety of methods including carving, chiseling, embossing, and painting applied to diverse materials such as terracotta, sandstone, soapstone, bone, shell, copper, silver, and gold. , Iravatham Mahadevan noted that about 90% of the Indus script seals and inscribed objects discovered so far were found at sites in Pakistan along the Indus river and its tributaries, such as Mohenjo-daro and Harappa, while other sites located elsewhere account for the remaining 10%. Often, animals such as bulls, water buffaloes, elephants, rhinoceros, and the mythical "unicorn" accompanied the text on seals, possibly to help the illiterate identify the origin of a particular seal. Late Harappan The Late Harappan period, from , followed the more urbanised Mature Harappan period, and was a period of fragmentation and localisation which preceded the early Iron Age in the Indian subcontinent. Inscriptions have been found at sites associated with the localised phases of this period. At Harappa, the use of the script largely ceased as the use of inscribed seals ended around ; however, the use of the Indus script may have endured for a longer duration in other regions such as at Rangpur, Gujarat, particularly in the form of graffiti inscribed on pottery. Seals from the Jhukar phase of the Late Harappan period, centred on the present-day province of Sindh in Pakistan, lack the Indus script, however, some potsherd inscriptions from this phase have been noted. Both seals and potsherds bearing Indus script text, dated , have been found at sites associated with the Daimabad culture of the Late Harappan period, in present-day Maharashtra. Post-Harappan Numerous artefacts, particularly potsherds and tools, bearing markings inscribed into them have been found in Central India, South India, and Sri Lanka dating to the Megalithic Iron Age which followed the Late Harappan period. These markings include inscriptions in the Brahmi and Tamil-Brahmi scripts, but also include non-Brahmi graffiti symbols which co-existed contemporaneously with the Tamil-Brahmi script. As