Agnostidae is a
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of
Agnostida trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
s. Like all Agnostina, they were eyeless and bore only two
thoracic
The thorax or chest is a part of the anatomy of humans, 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 divisions of the crea ...
segments. They ranged in
benthic waters across the globe from 508 to 461 million years ago, containing the following genera, among others:
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Acmarhachis''
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Agnostus
''Agnostus'' is a genus of agnostid trilobites, belonging to the family Agnostidae, that lived during the late Middle Cambrian – early Upper Cambrian (about 506 to 492 million years ago). It is the type genus of the family Agnostidae and is sub ...
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Aistagnostus''
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Anglagnostus''
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Biciragnostus''
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Connagnostus''
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Distagnostus''
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Eolotagnostus''
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Gymnagnostus''
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Homagnostus''
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Idolagnostus''
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Innitagnostus''
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Ivshinagnostus''
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Kymagnostus''
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Lotagnostus''
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Micragnostus''
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Obelagnostus''
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Oncagnostus''
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Peronopsis''
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Phalacroma''
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Phalagnostus''
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Quadrahomagnostus''
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Raragnostus''
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Semagnostus''
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Strictagnostus''
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Trilobagnostus''
References
Agnostoidea
Trilobite families
Cambrian first appearances
Middle Ordovician extinctions
{{agnostida-stub