Did the mayans develop a concept of zero?

Yes and no. But mostly yes.

The Mayans impressively developed a concept of zero as a number and as a placeholder. They did so in the 4th century AD, and what makes it especially impressive is that they more or less did so on their own, without borrowing from or exchanging ideas with other civilizations. 

However, unlike ancient India, who developed the concept of zero around the same time, the Maya never applied to to mathematical calculations, using it mostly as a placeholder and a concept in their complex calenders. 

Zero really becomes a powerful force in science and math when you begin applying the concept to equations. A number times zero is zero, a number divided by zero can't exist but theoretically is infinite, etc. Although the Mayans never applied zero to their impressive advancements in geometry, construction, etc, they did invent the concept essentially from scratch, which is an impressive feat that few other societies accomplished in the ancient world.