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  2. Trilobite - Wikipedia

    en.wikipedia.org/wiki/Trilobite

    Trilobites have been important in estimating the rate of speciation during the period known as the Cambrian explosion because they are the most diverse group of metazoans known from the fossil record of the early Cambrian. [51] [52] Trilobites are excellent stratigraphic markers of the Cambrian period: researchers who find trilobites with ...

  3. Trinucleidae - Wikipedia

    en.wikipedia.org/wiki/Trinucleidae

    Trinucleidae is a family of small to average size asaphid trilobites that first occurred at the start of the Ordovician and became extinct at the end of that period. It contains approximately 227 species divided over 51 genera in 5 subfamilies. [1] The most conspicuous character is the wide perforated fringe of the head.

  4. Olenelloides - Wikipedia

    en.wikipedia.org/wiki/Olenelloides

    Olenelloides armatus is an extinct, small sized (about 1 centimetre or 0.39 inches long) olenelloid redlichiid trilobite arthropod.It lived during the later part of the Botomian stage, [1] which lasted from approximately 524 to 518.5 million years ago.

  5. Eoredlichia - Wikipedia

    en.wikipedia.org/wiki/Eoredlichia

    Eoredlichia is an extinct genus of trilobite of average to large size (up to 12 centimetres or 4.7 inches long, or 20 centimetres or 7.9 inches when including the spine on the ninth thorax segment pointing horizontally to the back, that itself equals the main body length).

  6. Asaphellus - Wikipedia

    en.wikipedia.org/wiki/Asaphellus

    Asaphellus is an extinct genus of trilobites reported from the Ordovician. It is seen in Argentina, Bolivia, Mexico, America, Algeria, Iran, Spain, Portugal, France, Great Britain, Czech Republic, Norway, Sweden and China. [1] [2] [3]

  7. Emigrantia - Wikipedia

    en.wikipedia.org/wiki/Emigrantia

    As with most early trilobites, Emigrantia has an almost flat exoskeleton, that is only thinly calcified. As part of the Olenellina suborder, Emigrantia lacks dorsal sutures. Like all other members of the Olenelloidea superfamily, the eye-ridges spring from the back of the frontal lobe (L4) of the central area of the cephalon, that is called ...

  8. Archaeaspis - Wikipedia

    en.wikipedia.org/wiki/Archaeaspis

    Archaeaspis is an extinct genus of redlichiid trilobites. It lived during the late Atdabanian stage, [3] which lasted from 521 to 514 million years ago during the early part of the Cambrian Period. The first specimens were first found in Siberia, where they were originally thought to have been endemic.

  9. Ogygiocarella - Wikipedia

    en.wikipedia.org/wiki/Ogygiocarella

    Ogygiocarella is arguably the first trilobite that was scientifically described. Rev. Edward Lhwyd [4] published in 1698 in The Philosophical Transactions of the Royal Society, the oldest scientific journal in the English language, part of his letter “Concerning Several Regularly Figured Stones Lately Found by Him", that was accompanied by a page of etchings of fossils. [5]