Acastoides sp.DevonianMorocco Receive one, random trilobite hand selected just for you! Pictures are representative of what you may receive, however actual piece varies. *Choose from one of the variants below: $3 each or 5 trilobites for $10 These are tiny Acastoides trilobites from Morocco. They range in size from approx. 1/4" to 1/2". Some might be larger, but they are usually on the smaller end of this range. Trilobites instinctively enrolled themselves in a defensive posture, resulting in them frequently being found preserved in this position. Trilobites, exclusively marine animals, first appeared at the beginning of the Cambrian Period, about 542 million years ago, when they dominated the seas. Although they became less abundant in succeeding geologic periods, a few forms persisted into the Permian Period, which ended about 251 million years ago.
