Geological evidence indicates that much of Bangladesh was formed 1 to 6.5 million years ago during the Tertiary Era. Human habitation in this region is, therefore, likely to be very old.
The implements discovered in Deolpota village in the neighbouring state of West Bengal suggest that a paleolithic civilization in the region existed about one hundred thousand years ago. The evidence of a paleolithic civilization in Bangladesh region is limited to a stone implement in Rangamati and a hand axe in the hilly tip of Feni district. They are likely to be 10,000 to 15,000 years old.
The New Stone Age in the region lasted from 3,000 B.C. to 1,500 B.C. Neolithic tools comparable to the Assam group were found at Sitakunda in Chittagong. Hand axes and chisels which show a close affinity to neolithic industries in West Bengal, Bihar and Orissa have been discovered at Mainamati near Comilla. The thinly forested laterite hills in eastern Bengal dotted with fertile valleys provided a congenial environment for neolithic settlements.
However, archaeological evidence on the transition from the stone age to the metal age in this region is still missing.