Trilobite Hunting Grand Find: OLENELLUS fremontii


By Joseph “PaleoJoe” Kchodl

Nevada is known for its grand casinos, but for trilobite hunters, it is known for grand Cambrian trilobites. Equally grand, in terms of trilobite size, is the Nevada native OLENELLUS fremontii.

This type of trilobite is known to grow up to four inches in length, double the standard size of various other genres. Additionally, most OLENELLUS fremontii trilobites reveal upward of 30 body segments, with each section ending in spines of varying lengths. One of the thoracic spines is larger than the others and ends in long spines that extend past the tail section. The cephalon of OLENELLUS fremontii is semi-circular and ends with very long genal spines, and are often extensively ornamented.

Examples of OLENELLUS fremontii are found preserved in the Pioche Formation of the Klondike Gap of Nevada, and are highly sought-after fossil hunters and collectors.

Trilobites, an extinct form of arthropod related to insects, crabs, crayfish, and horseshoe crabs, are among the most prevalent invertebrates with hard body parts to appear during the Cambrian Period. These creatures are called trilobite due to the three distinct “lobes” running vertically through the body section.

Joseph “PaleoJoe” Kchodl and his daughter, Jen “PaleoJen” Kchodl.

About the columnist: Joseph “PaleoJoe” Kchodl is a paleontologist, educator, veteran, author, fossil dig organizer/guide, business owner, husband, father, and grandfather, and fossil fanatic. For decades, he’s spent hours in classrooms around the Midwestern United States and beyond, speaking to school children about fossils and fossil hunting. Visit his site to purchase fossils, contact PaleoJoe, visit

Plus, learn more about PaleoJoe and his daughter PaleoJen and their paleontology exploration partnership in an the article Fueling a Passion for Paleontology.

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