Dalmanites limulurus-New York

Taxa: Dalmanites limulurus

Geology: Rochester Shale

Age: Silurian

Locality: Middleport, New York

This specimen has some restoration to the edges and tail spine.

Dalmanites

Dalmanites is an extinct genus of trilobites that lived from the Ordovician to the Devonian period. Belonging to the order Phacopida, Dalmanites is characterized by an elongated body, a well-defined glabella (central head lobe), and large, crescent-shaped compound eyes. A distinctive feature of this genus is its long, spiny pygidium (tail piece), which may have served as a defense mechanism. Fossils of Dalmanites have been found in North America, Europe, Africa, and South America, providing valuable insights into ancient marine ecosystems.

 Trilobites

Trilobites lived from the Cambrian into the Permian. There are over 25,000 known species and their hard exoskeleton is the reason we have such a good understanding of these animals. Trilobite (“three lobed”) are extinct arthropods. Their bodies were devided into three parts: the cephalon (head), the body (thorax), and the pygidium (tail). Trilobite fossils are found worldwide, with many thousands of known species. Because they are so common, trilobites serve as excellent index fossils. This means that identifying the type of trilobite enables geologist to date and age the rocks in which they are found. When threatened some trilobites acted much like today's pillbugs—tucking in their legs and antennae, by bending the thorax and bringing the tail underneath the head. Trilobites roll up in a ball for protection providing additional protection for the appendages and soft parts.