Tethys Ocean
Sea levels were high worldwide, and much of the land lay under shallow seas, where tropical reef organisms lived. The deep, enormous Panthalassa (the "universal ocean") covered the rest of the planet. Other minor oceans were the Paleo-Tethys Ocean, Proto-Tethys Ocean, Rheic Ocean, and Ural Ocean (which was closed during the collision with Siberia and Baltica).