Several stone sculptures recently found in central Mexico point to a previously unknown culture that likely built a mysterious pyramid in the region, archaeologists say.

Archaeologists first found the objects about 15 years ago in the valley of Tulancingo, a major canyon that drops off into Mexico's Gulf Coast.

Most of the 41 artifacts"do not fit into any of the known cultures of the Valley of Tulancingo, or the highlands of central Mexico," said Carlos Hernández, an archaeologist at Mexico's National Institute of Anthropology and History in the central state of Hidalgo.