"To date, the earliest Mother Goddess figurine unearthed in India (near Prayagraj) belongs to the Upper Paleolithic, and carbon-dates to approximately 20,000 - 23,000 BCE. Also belonging to that period are some collections of colorful stones marked with natural triangles. Discovered near Mirzapur in Uttar Pradesh, they are similar to stones still worshiped as Devi by tribal groups in the area. Moreover, they "may demonstrate connections to the later Tantric use of yantras, in which triangles manifest a vital symbolism connected with fertility.""It would be kind of interesting to see a link on that cult.
History of Shaktism - Wikipedia
en.wikipedia.org
(The lingum and yoni symbols (the "triangle" that's mentioned) are fertility symbols representing male and female generative powers stretching back to prehistoric fertility cults.)