Sousei No Taiga is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

A story of a young man who lacks a sense of reality after being dumped by his lover. He was visiting a seminar on cultural anthropology with his fellow classmates when he discoveres an ancient wall painting, which transports him to the past where mammoths dominated the world.Action