|Closeup of trilobite tail pieces.|
Trilobites are extinct marine arthropods. The carapace consists of three parts:
- Cephalon (head shield)
- Thorax (articulated body segments)
- Pygidium (tail piece)
|Slab of shale with trilobite carapaces.|
The slab in the photo above is about two feet square and contains many tail pieces. These are likely Pseudogygites latimarginatus which is one of the more common species found in the area. A reconstruction of the complete carapace is shown below.
|Source: The Ordovician trilobite Pseudogygites Kobayashi in eastern and Arctic North America|
Trilobites are similar to the modern horseshoe crab which can be found along the east coast of North America. As a child I would frequently find these "living fossils" crawling in the sand on the beaches of Narragansett Bay in Rhode Island.
- The Geology and Fossils of the Craigleith Area (2.2 MB PDF)