________ __was an ancient civilization that lived in the tropical lowlands of what is now Mexico from about 1400 BCE to 400 BCE. They are known for their monumental stone heads, jade carvings, and their influence on later Mesoamerican cultures.__ ________ are considered to be the "mother culture" of Mesoamerica, as many of their religious, artistic, and architectural traditions were adopted and adapted by later civilizations such as the Maya and the Aztecs.