Ключевые слова: ancient, animal, antique, archeology, arthropod, cambrian, dinosaur, era, evolution, exoskeleton, extinct, fossil, fossilization, fossilized, geological, geology, history, invertebrate, marine, middle cambrian, mineral, morocco, museum, nature, ocean, old, paleontology, paleozoic, pattern, prehistoric, prehistory, rock, science, sea, skeleton, stone, texture, trilobite,