The Last of Their Kind
Trilobites

• Olenellus trilobites found at the Southern end of the Marble Mountains.
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  Trilobites were the first animals to have eyes.
• Human beings have one lens in each eye, but some trilobites had as many as 20,000.
• Eight orders of Trilobites are recognized, into which 15,000+ species are classified.
• Trilobites appeared 570 million years ago and are the ancestors of today's shrimps and lobsters.
• The last of the trilobites disappeared about 230 million years ago.
• Trilobites are the single most diverse group of animals preserved in the fossil record.

• The embryology of trilobites is unknown, but after hatching and development of a hard exoskeleton (which presumably occurred soon after hatching) they molted their exoskeletons as they grew, as all arthropods today, leaving a record of their developmental stages.

For more information about trilobites, visit A Guide to the Orders of Trilobites . Believe me, you'll be amazed!