What group of people is known as the oldest culture in mesoamerica?

The Olmec civilization is considered the oldest known culture in Mesoamerica, flourishing around 1400 to 400 BCE. They are recognized for their significant contributions to art, architecture, and the development of early hieroglyphic writing. The Olmecs are often referred to as the "mother culture" of later Mesoamerican civilizations, such as the Maya and Aztecs, due to their influence on subsequent societies. Their most iconic symbols include colossal stone heads and intricate jade carvings.