Asaphus kowalewskii
Encyclopedia
Asaphus kowalewskii is one of the 35 species of trilobite
of the genus
Asaphus (this particular species is sometimes placed in its own genus, Neoasaphus). Fossil
s of this species are popular among collectors because of their prominent stalked eyes
(termed "peduncles"), many an inch or more in length.
In the Ordovician
period, an inland sea formed in what is now Eastern Europe. The sea contained a remarkably diverse trilobite fauna. Over a dozen species of Asaphus developed in this sea, with many species, including unrelated species, developing long eyestalksin various lengths. That so many species of trilobite developed eyestalks suggests that they were trying to overcome increased turbidity
, or there was some sort of massive selective pressure leading these trilobites to bury themselves in the substrate up to their eyes. This species may have lain in wait buried in a benthic layer of loose debris or sediment with only its periscope eyestalks protruding above, looking out for danger or prey.
The fossils of this species are found only in the middle Ordovician deposits of the Volkhov River
region near Saint Petersburg
, Russia
.
Trilobite
Trilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period , and they flourished throughout the lower Paleozoic era before...
of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Asaphus (this particular species is sometimes placed in its own genus, Neoasaphus). Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of this species are popular among collectors because of their prominent stalked eyes
Eyestalk
In anatomy, an eyestalk is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction....
(termed "peduncles"), many an inch or more in length.
In the 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...
period, an inland sea formed in what is now Eastern Europe. The sea contained a remarkably diverse trilobite fauna. Over a dozen species of Asaphus developed in this sea, with many species, including unrelated species, developing long eyestalksin various lengths. That so many species of trilobite developed eyestalks suggests that they were trying to overcome increased turbidity
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality....
, or there was some sort of massive selective pressure leading these trilobites to bury themselves in the substrate up to their eyes. This species may have lain in wait buried in a benthic layer of loose debris or sediment with only its periscope eyestalks protruding above, looking out for danger or prey.
The fossils of this species are found only in the middle Ordovician deposits 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...
region near Saint Petersburg
Saint Petersburg
Saint Petersburg is a city and a federal subject of Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
.