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.

Many of the figures are depicted in a sitting position, with their hands placed on their knees.

Some have headdresses or conical hats with snakes at the base, which could represent Ehécatl-Quetzalcóatl, the Aztec god of the wind. One figure shows a man emerging from the jaws of a jaguar.

The sculptures are also made of flat stucco—a combination of fine sand, lime, and water—and painted blue or green to the give the appearance of jade.

All of the artifacts date to the Epiclassic period between A.D. 600 to 900.

Some Mexican and foreign archaeologists have said the sculptures weren't ancient and thus false, Hernández said.

"But by linking all the characteristics that make them different, [such as their location in Tulancingo and time period], allows us to say that they should be considered as a product of a different culture [called Huajomulco]."

The culture is named after an area in Hidalgo.

Baffling Pyramid

Some of the artifacts were also found near the mysterious Huapalcalco pyramid in Hidalgo, whose origin has been a source of debate among archaeologists.

The pyramid's proportions, along with smaller structures that were painted black and white, do not correspond to the Toltec or Teotihuacan cultures of the same area and time period.