Complex sentence: Rampart craters are a specific type of impact crater which are accompanied by distinctive fluidized ejecta features found mainly on Mars with one example known on Earth, the Nördlinger Ries impact structure in Germany.
Split into simpler sentences: Rampart craters are a specific type of impact crater which are accompanied by distinctive fluidized ejecta features found mainly on Mars. There is one example known on Earth, the Nördlinger Ries impact structure in Germany.