MP4 : Dr. Fazale Rana: What do fossils tell us What is the importance of Cambrian period fossilsMP3 : Dr. Fazale Rana: What do fossils tell us What is the importance of Cambrian period fossilsMP4 720p : Dr. Fazale Rana: What do fossils tell us What is the importance of Cambrian period fossilsMP4 480p : Dr. Fazale Rana: What do fossils tell us What is the importance of Cambrian period fossils