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Trilobitomorpha

Trilobites
Temporal range: 521–250 Ma
Early Cambrian – Late Permian
Kainops invius lateral and ventral.JPG
Kainops invius, early Devonian
Paradoxides sp.jpg
Paradoxides sp., late Cambrian
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Trilobitomorpha
Class: Trilobita
Walch, 1771
Orders

Trilobites (pronunciation: /ˈtrləˌbt, ˈtrɪ-, -l-/; meaning "three lobes") are a fossil group of extinct marine arachnomorph 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 Atdabanian stage of the Early Cambrian period (521 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except the Proetids died out. Trilobites finally disappeared in the mass extinction at the end of the Permian about 250 million years ago. The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years.


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Wikipedia

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