''Olenoides'' was a

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

from the

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

period. Its fossils are found well-preserved in the

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fos ...

in Canada. It grew up to 10 cm (3.9 in) long.

Etymology

''Olenoides'' – from ''Olenus'', in Greek mythology a man who, along with his wife Lethaea, was turned to stone. ''Olenus'' was used for a trilobite genus name in 1827; the suffix -''oides''(“resembling”) was added later.

Discussion

''Olenoides'' followed the basic structure of all trilobites — a

cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino Jr., Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont ...

(head shield), a

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

with seven jointed parts, and finally a semicircular

pygidium The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is compos ...

. Its antennae were long, and curved back along its sides. Its thin legs show that it was no swimmer, instead crawling along the sea floor in search of prey. This is also evidenced by fossil tracks that have been found. Conspicuous W-shaped wounds, often partially healed, on ''Olenoides'' specimens may be due to predation by ''

Anomalocaris ''Anomalocaris'' (from Ancient Greek , meaning "unlike", and , meaning "shrimp", with the intended meaning "unlike other shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group marine arthropods. It is best known fro ...

''. Its major characteristics are a large parallel-sided

glabella The glabella, in humans, is the area of skin between the eyebrows and above the nose. The term also refers to the underlying bone that is slightly depressed, and joins the two brow ridges. It is a cephalometric landmark that is just superior ...

, deep interpleural furrows on the

, and slender pygidial spines, as well as the fact that it is the most common limb-bearing trilobite species in the

. Specimens have been found in the Marjumian of the United States (

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

and

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

). General

fossils have been found in Canada (

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

and

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

, Russia, and the USA (

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

for which ''O. nevadensis'' is named,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

for which ''O. pennsylvanicus'' is named,

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

, and

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

). 213 specimens of ''Olenoides'' are known from the Greater Phyllopod bed, where they comprise 0.4% of the community. The Burgess Shale's preservative qualities have helped ''Olenoides'' become one of the best known of trilobites.

Synonyms

Olenoides serratus oblique with antennas

''Olenoides'' was formerly known as ''Neolenus''. Species of '' Kootenia'' are no longer considered different enough from those in ''Olenoides'' to warrant placement in a separate genus.Coppold, Murray and Wayne Powell (2006). ''A Geoscience Guide to the Burgess Shale'', p.59. The Burgess Shale Geoscience Foundation, Field, British Columbia. .

Species

* ''O. nevadensis'' * ''O. sassikaspa'' * ''O. serratus'' * ''O. dawsoni'' (formerly placed in ''Kootenia'') * ''O. burgessensis'' (formerly placed in ''Kootenia'') * ''O. buttsi'' (unrecognized) * ''O. convexus'' (unrecognized) * ''O. incertus'' (unrecognized) * ''O. pennsylvanicus'' (unrecognized)

Description

''Olenoides'' is an average size trilobite (up to 9 cm long), broadly oval in outline. Its

is semi-circular. The glabella is parallel-sided, rounded at its front and almost reaches the anterior border. Narrow occular ridges curve backwards from the front of the glabella to the small, outwardly-bowed eyes. The librigenae narrow backward into straight, slender genal spines that reach as far as the third thorax segment. Thorax consists of seven segments that end in needle-like spines.

) has six axial rings that decrease in size backwards and four or five pairs of rearward pointing marginal spines. Cephalon, thorax and pygidium are of approximately equal length. ''Olenoides serratus'' is one of about twenty species of which the non-calcified parts are known, due to so-called soft tissue preservation. The antennae are the most anterior pair of appendages in trilobites. In ''O. serratus'', these are attached about halfway the immediately adjacent to the hypostome, and appear from the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

side under the cephalon in front of the side of the glabella. They were flexible, having a tubular shape that became narrower towards anterior and composed of between 40 and 50 segments that are each shorter than wide. ''Olenellus serratus'' is the only known trilobite with cerci, uniramous

appendages An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface app ...

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

side of last pygidial segment, and these are shaped like the antennas.

References

''Olenoides'' on the Smithsonian institution website

''Paleozoic Olenoides Yu-Gi-Oh!''

External links

* {{Taxonbar, from=Q2321982 Corynexochida genera Dorypygidae Burgess Shale fossils Fossil taxa described in 1877 Wheeler Shale Paleozoic life of Newfoundland and Labrador Cambrian trilobites Cambrian genus extinctions