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333:(tail) parts similar in size, and most species have a prominent median ventral suture. Heads are often flat, and carapace furrows in the head area are often faint or not visible. Thoracic segments typically number 5 - 12, though some species have as few as two and some as many as 30. They also generally have a wide doublure, or rim, that surrounds the cephalon. This causes some specimens to be described as having a characteristic "snowplow" shaped cephalon. When present, eyes are typically large.
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The major extinction event marking the end of the
Ordovician Period reduced the diversity of all trilobite orders with most asaphid families disappearing. The only surviving asaphids were members of superfamily
378:
was a shallow inland sea. This eyestalk development is believed to be an adaptation to changes in turbidity during this time, with eye-stalked trilobites like
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presumably arising in a time of increased turbidity. One thought is that this trilobite may have lain in wait for prey buried in the bottom
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287:(Anomocaroidea, Asaphoidea, Cyclopygoidea, Dikelocephaloidea, Remopleuridoidea and Trinucleioidea), but no
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Bignon, Arnaud; Waisfeld, Beatriz G.; Vaccari, N. Emilio; Chatterton, Brian D. E. (2020-07-02).
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362:. This line is found in the Middle Ordovician Asery Level deposits of the
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One
Asaphida line, the Superfamily Asaphoidea, shows a continuous
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374:. During the Ordovician, the region that is now Eastern
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The following superfamilies and families are included:
19:"Loganellidae" redirects here. Not to be confused with
651:"Reassessment of the Order Trinucleida (Trilobita)"
352:of eyestalks, from individuals with stubby eyes to
394:, and they too disappeared before the end of the
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386:with only its periscope eyestalks protruding.
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291:. Asaphids comprise some 20% of described
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302:was proposed to be raised to an order (
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622:(includes Mapaniidae, Plectriferidae)
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263:is a large, morphologically diverse
655:Journal of Systematic Palaeontology
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279:until their extinction during the
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1:
675:10.1080/14772019.2020.1720324
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309:
306:) and removed from Asaphida.
895:. You can help Knowledge by
628:(Chelidonocephalidae ?)
325:The Asaphids generally have
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16:Extinct order of trilobites
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967:Cambrian first appearances
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298:In 2020, the superfamily
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126:Scientific classification
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406:Damghanampyx ghobadipour
358:, a trilobite with long
283:. Asaphida contains six
37:Middle Cambrian–Silurian
891:-related article is a
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275:dated from the Middle
209:& Chatterton, 1988
952:Ordovician trilobites
854:Paleobiology Database
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972:Silurian extinctions
957:Silurian trilobites
947:Cambrian trilobites
667:2020JSPal..18.1061B
355:Asaphus kowalewskii
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342:Asaphus kowalewski
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841:Open Tree of Life
729:Taxon identifiers
661:(13): 1061–1077.
547:Remopleuridioidea
514:Dikelokephaloidea
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235:Dikelokephaloidea
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118:Asaphus lepidurus
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706:"Order Asaphida"
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519:Dikelocephalidae
506:Taihungshaniidae
453:Pterocephaliidae
448:Parabolinoididae
368:Saint Petersburg
271:found in marine
240:Remopleuridoidea
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34:Temporal range:
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380:A. kowalewski
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21:Loganelliidae
897:expanding it
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709:. Retrieved
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606:Trinucleidae
578:Superfamily
557:Bohemillidae
552:Auritamiidae
545:Superfamily
529:Loganellidae
512:Superfamily
489:Cyclopygidae
482:Superfamily
459:Superfamily
438:Anomocaridae
428:Andrarinidae
421:Superfamily
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388:
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366:region near
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295:trilobites.
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815:iNaturalist
761:Wikispecies
476:Tsinaniidae
329:(head) and
304:Trinucleida
977:Librostoma
936:Categories
636:References
591:Dionididae
567:Idahoiidae
562:Hungaiidae
524:Eurekiidae
494:Isocolidae
461:Asaphoidea
319:Asaphellus
310:Morphology
269:trilobites
230:Asaphoidea
189:Librostoma
182:Subclass:
163:Arthropoda
691:212995185
683:1477-2019
539:Saukiidae
466:Asaphidae
360:eyestalks
350:evolution
289:suborders
176:Trilobita
149:Kingdom:
143:Eukaryota
942:Asaphida
889:Asaphida
767:Asaphida
746:Wikidata
737:Asaphida
582: ?
500:Nileidae
412:Taxonomy
398:Period.
396:Silurian
384:sediment
331:pygidium
327:cephalon
281:Silurian
277:Cambrian
261:Asaphida
202:Asaphida
159:Phylum:
153:Animalia
139:Domain:
31:Asaphida
846:5301992
807:9573072
794:4324586
752:Q220877
663:Bibcode
195:Order:
169:Class:
820:317829
711:9 July
689:
681:
376:Europe
372:Russia
293:fossil
273:strata
207:Fortey
887:This
859:19834
833:10008
828:IRMNG
687:S2CID
265:order
893:stub
802:GBIF
713:2018
679:ISSN
42:PreꞒ
789:EoL
776:CoL
671:doi
267:of
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781:RD
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321:sp
92:Pg
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502:?
496:?
252:?
199:†
186:†
173:†
97:N
87:K
82:J
77:T
72:P
67:C
62:D
57:S
52:O
47:Ꞓ
23:.
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