Ceraurus
Encyclopedia
Ceraurus is a genus of cheirurid trilobite
of the middle and, much more rarely, the upper Ordovician
. They are commonly found in strata of the lower Great Lakes
region. These trilobites have eleven thoracic segments, a very small pygidia and long genal and pygidial spines.
Ceraurus is quite common in the Ordovician of upstate New York
, south-central and south-eastern Ontario
, and the St. Lawrence Valley in Quebec, as well as in the Canadian Arctic. It and similar genera range in size from less than quarter an inch to well over five inches. Similar genus of trilobites occur in the Ordovician outcrops of the Volkhov River
, near St. Petersburg, Russia.
The taxonomy of the genus is very confusing, as there are many variations of eye placement, pustulation, and spine length. Ceraurus may, in fact, be at least four genera: true Ceraurus, Gabriceraurus, Bufoceraurus and Leviceraurus.
Cheiruridae
The family Cheiruridae was a family of phacopid trilobites of the suborder Cheirurina. Its members, as with other members of the suborder, had distinctive pygidia modified into finger-like spines. They first appeared near the very beginning of the Ordovician, and persisted until the...
of the middle and, much more rarely, the upper Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
. They are commonly found in strata of the lower Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
region. These trilobites have eleven thoracic segments, a very small pygidia and long genal and pygidial spines.
Ceraurus is quite common in the Ordovician of upstate New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
, south-central and south-eastern Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, and the St. Lawrence Valley in Quebec, as well as in the Canadian Arctic. It and similar genera range in size from less than quarter an inch to well over five inches. Similar genus of trilobites occur in the Ordovician outcrops of the Volkhov River
Volkhov River
Volkhov is a river in Novgorod Oblast and Leningrad Oblast in northwestern Russia.-Geography:The Volkhov flows out of Lake Ilmen north into Lake Ladoga, the largest lake of Europe. It is the second largest tributary of Lake Ladoga. It is navigable over its whole length. Discharge is highly...
, near St. Petersburg, Russia.
The taxonomy of the genus is very confusing, as there are many variations of eye placement, pustulation, and spine length. Ceraurus may, in fact, be at least four genera: true Ceraurus, Gabriceraurus, Bufoceraurus and Leviceraurus.