792:
452:, an intestine, and a short rectum. The pharynx is muscular and lined by teeth. Three of the five extant families have gone through a significant miniaturization and become detritivores (Tubiluchidae and Meiopriapulidae) and filter feeders (Chaetostephanidae). The two remaining families Priapulidae and Halicryptidae are larger carnivores that feed on other animals, although some species also consume detritus as larvae. The shape of the teeth reflect these different lifestyles, and seem to be adapted mainly towards grasping prey or raking detritus from the sediment into the mouth. The anus is terminal, although in
723:
657:
812:
545:
131:
528:
703:
1417:
109:
1915:
637:
762:
407:
longitudinal ridges. The body is ringed and often has circles of spines, which are continued into the slightly protrusible pharynx. Family
Priapulidae have species with a tail or a pair of caudal appendages. A slender tail or tail filament is also found in family Tubiluchidae. Appendages are absent in the remaining families. The body has a
510:, the 80 μm egg undergoes a total and radial cleavage following a symmetrical and subequal pattern. Development is remarkably slow, with the first cleavage taking place 15 hours after fertilization, gastrulation after several days and hatching of the first 'lorica' larvae after 15 to 20 days. The species
497:
and other animals, and these probably function as excretory organs. As the animals mature, diverticula arise on the tubes of these organs, which develop either spermatozoa or ova. These sex cells pass out through the ducts. The perigenital area of the genus
Tubiluchus exhibit sexual dimorphism.
406:
Priapulids are cylindrical worm-like animals, ranging from 0.2–0.3 to 39 centimetres (0.08–0.12 to 15.35 in) long, with a median anterior mouth quite devoid of any armature or tentacles. The body is divided into a main trunk or abdomen and a somewhat swollen proboscis region ornamented with
366:
is identical with that of priapulids, indicating that their mouth is an original trait inherited from the last common ancestor of both priapulids and arthropods, even if modern arthropods no longer possess it. Among
Ecdysozoa, their nearest relatives are
576:(corresponding to the various teeth and spines that line the pharynx and introvert) are widespread in Cambrian deposits, allowing the distribution of priapulids – and even individual species – to be tracked widely through Cambrian oceans.
514:
have direct development. In current systematics, they are described as protostomes, despite having a deuterostomic development. Because the group is so ancient, it is assumed the deuterostome condition which appears to be ancestral for
2083:
Dunn, C. W.; Hejnol, A.; Matus, D. Q.; Pang, K.; Browne, W. E.; Smith, S. A.; Seaver, E.; Rouse, G. W.; Obst, M. (10 April 2008). "Broad
Phylogenomic Sampling Improves Resolution of the Animal Tree of Life".
394:. They were likely major predators of the Cambrian period. However, crown-group priapulids cannot be recognized until the Carboniferous. 22 extant species of priapulid worms are known, half of them being of
791:
2920:
590:
period, suggesting that priapulids, or at least close anatomical relatives, evolved around this time. Crown-group priapulid body fossils are first known from the
Carboniferous.
2895:
493:. They comprise a pair of branching tufts, each of which opens to the exterior on one side of the anus. The tips of these tufts enclose a flame-cell like those found in
4562:
1954:
Oeschger, R.; Janssen, H. H. (September 1991). "Histological studies on
Halicryptus spinulosus (Priapulida) with regard to environmental hydrogen sulfide resistance".
506:
Priapulid development has been reappraised recently because early studies reported abnormal development caused by high temperature of embryo culture. For the species
5267:
5154:
5180:
572:, where their soft-part anatomy is preserved, often in conjunction with their gut contents – allowing a reconstruction of their diets. In addition, isolated
411:
cuticle that is moulted as the animal grows. Members of the family
Chaetostephanidae also secretes a gelatinous tube, open in both ends, which they live in.
1991:"Cryptic species complex or an incomplete speciation? Phylogeographic analysis reveals an intricate Pleistocene history of Priapulus caudatus Lamarck, 1816"
1939:
2264:
5128:
2760:
Vannier, J.; Calandra, I.; Gaillard, C.; Zylinska, A. (2010). "Priapulid worms: Pioneer horizontal burrowers at the
Precambrian-Cambrian boundary".
5167:
4268:
1930:
2905:
2482:
2333:
2306:
2274:
2173:
2146:
2053:
2028:
The phylogeny, classification and zoogeography of the class
Priapulida. II. Revision of the family Priapulidae and zoogeography of priapulids
301:. The name of the phylum relates to the Greek god of fertility, because their general shape and their extensible spiny introvert (eversible)
309:. They live in the mud and in comparatively shallow waters up to 90 metres (295 ft) deep. Some species show a remarkable tolerance for
325:
appears to prefer brackish shallow waters. They can be quite abundant in some areas. In an
Alaskan bay as many as 85 adult individuals of
329:
per square meter has been recorded, while the density of its larvae can be as high as 58,000 per square meter (5,390 per square foot).
2982:
2323:
1989:
Kolbasova, Glafira; Schmidt-Rhaesa, Andreas; Syomin, Vitaly; Bredikhin, Danila; Morozov, Taras; Neretina, Tatiana (January 2023).
5229:
3019:
2354:"Geometric morphometrics of macro- and meiofaunal priapulid pharyngeal teeth provides a proxy for studying Cambrian "tooth taxa""
2136:
2043:
3014:
2189:
Shirley, Thomas C.; Storch, Volker (1999). "Halicryptus higginsi n.sp. (Priapulida): A Giant New Species from Barrow, Alaska".
1408:
2655:
Higgins, Robert P.; Storch, Volker (January 1991). "Evidence for Direct Development in Meiopriapulus fijiensis (Priapulida)".
1883:"Northern and Arctic Invertebrates in the Collection of the Swedish State Museum (Riksmuseum). II. Priapulids, Echiurids etc"
5172:
489:, having two separate sexes (i.e. male and female). Their male and female organs are closely associated with the excretory
3098:
3088:
3071:
5102:
5089:
4261:
2795:
Slater, Ben J.; Harvey, Thomas H. P.; Guilbaud, Romain; Butterfield, Nicholas J. (January 2017). Rahman, Imran (ed.).
130:
2352:
Wernström, Joel Vikberg; Slater, Ben J.; Sørensen, Martin V.; Crampton, Denise; Altenburger, Andreas (2023-08-12).
467:
and longitudinal and transversal neurites consistent with an orthogonal organisation. The nervous system retains a
5185:
4405:
2163:
573:
548:
5262:
722:
4490:
3103:
656:
2931:
Adrianov A. V, Malakhov V. V. 2001. Symmetry of priapulids (Priapulida). 1. Symmetry of adults. 247:99–110.
1838:
Budd, G. E.; Jensen, S. (May 2000). "A critical reappraisal of the fossil record of the bilaterian phyla".
414:
There is a wide body-cavity, which has no connection with the renal or reproductive organs, so it is not a
5042:
4254:
2975:
2069:
5107:
5206:
4718:
4368:
3066:
2953:
2027:
1006:
2921:
2019 Annual Checklist : Browse taxonomic classification phylum: Cephalorhyncha, class: Priapulida
811:
5234:
5115:
4383:
2866:
2808:
2769:
2707:
2237:
2093:
2002:
463:
consists of a nerve ring around the pharynx and a prominent cord running the length of the body with
1031:
5257:
468:
435:
1720:
1635:
1247:
901:
4713:
4395:
3531:
3083:
3061:
3049:
3024:
2743:
2672:
2582:
2531:
2424:
2225:
2206:
2117:
1990:
1971:
1863:
1762:
427:
423:
125:
117:
5211:
1784:
544:
5193:
4505:
3953:
3873:
3223:
3093:
3056:
3044:
3034:
2968:
2901:
2725:
2637:
2574:
2550:
2478:
2385:
2329:
2302:
2270:
2169:
2142:
2109:
2049:
1855:
1598:
1122:
885:
582:
532:
527:
5198:
380:
5221:
4781:
4660:
4552:
4495:
4435:
4430:
4358:
4343:
3008:
2874:
2826:
2816:
2777:
2715:
2664:
2627:
2617:
2566:
2521:
2511:
2500:"A new meiobenthic priapulid (Priapulida, Tubiluchidae) from a Mediterranean submarine cave"
2455:
2416:
2375:
2365:
2245:
2198:
2101:
2010:
1963:
1920:
One or more of the preceding sentences incorporates text from a publication now in the
1847:
1654:
1439:
1274:
565:
445:
310:
294:
5080:
702:
5159:
4954:
4859:
4821:
4776:
4708:
4465:
4425:
4410:
4303:
4234:
4140:
3991:
3894:
3751:
3284:
1211:
955:
490:
479:
4246:
2870:
2812:
2773:
2711:
2241:
2097:
2006:
5014:
4959:
4949:
4791:
4605:
4557:
4470:
4445:
4440:
4420:
4415:
4318:
4308:
3899:
3695:
3607:
3585:
3548:
3039:
2632:
2601:
2224:
Schmidt-Rhaesa, Andreas; Rothe, Birgen H.; Martínez, Alejandro García (November 2013).
1926:
1851:
1676:
1105:
460:
1416:
5251:
4738:
4723:
4685:
4610:
4546:
4532:
4480:
4475:
4389:
4378:
4373:
4353:
4348:
4323:
4044:
3948:
3447:
2797:"A cryptic record of Burgess Shale-type diversity from the early Cambrian of Baltica"
2570:
2459:
2039:
1934:
1921:
1644:
1592:
1448:
1145:
1051:
744:
577:
569:
537:
486:
314:
66:
2586:
2535:
2442:
Rothe, B. H.; Schmidt-Rhaesa, A. (Winter 2010). "Structure of the nervous system in
1975:
1882:
1867:
4934:
4929:
4904:
4879:
4869:
4796:
4665:
4539:
4500:
4485:
4460:
4455:
4400:
4333:
4150:
4145:
4033:
3889:
3775:
3661:
3564:
3543:
3413:
3364:
3320:
3301:
2121:
1730:
1698:
1544:
1016:
718:
619:
438:
431:
376:
362:
234:
5094:
344:, but consistent morphological and molecular evidence supports their belonging to
108:
5141:
5074:
4989:
4964:
4909:
4884:
4806:
4801:
4766:
4756:
4450:
4363:
4111:
4082:
4068:
4058:
3643:
3459:
3372:
3154:
2690:
Martín-Durán, J. M.; Janssen, R.; Wennberg, S.; Budd, G. E.; Hejnol, A. (2012).
1497:
1190:
1168:
1152:
1115:
980:
757:
652:
636:
482:, but there are sensory nerve endings in the body, especially on the proboscis.
395:
368:
175:
41:
2370:
2353:
5022:
4984:
4914:
4889:
4874:
4844:
4816:
4771:
4761:
4733:
4728:
4670:
4645:
4338:
4313:
4208:
4193:
4188:
4169:
4164:
4092:
4039:
4009:
4001:
3943:
3817:
3809:
3792:
3572:
3484:
3437:
3339:
3313:
3159:
3144:
2720:
2691:
2516:
2499:
2249:
2014:
1666:
1071:
807:
787:
456:
one or two hollow ventral diverticula of the body-wall stretch out behind it.
384:
372:
357:
211:
86:
51:
34:
2389:
4939:
4919:
4811:
4690:
4625:
4615:
4600:
4595:
4576:
4328:
4174:
4121:
4116:
4087:
4076:
4025:
4020:
3972:
3884:
3877:
3671:
3666:
3628:
3477:
3469:
3398:
3350:
3271:
3258:
3239:
3234:
3193:
2945:
1805:
1772:
1740:
1708:
1294:
928:
774:
685:
609:
516:
349:
345:
337:
302:
221:
201:
188:
162:
142:
91:
2729:
2641:
2578:
2113:
1859:
2622:
5065:
5059:
4994:
4974:
4969:
4944:
4924:
4899:
4864:
4854:
4849:
4680:
4655:
4635:
4295:
4198:
4182:
4105:
4097:
4052:
4015:
3996:
3985:
3967:
3961:
3822:
3763:
3739:
3636:
3517:
3406:
3290:
3181:
3172:
3078:
2847:
2405:"Evidence for Direct Development in Meiopriapulus fijiensis (Priapulida)"
698:
587:
494:
472:
464:
419:
391:
353:
341:
318:
81:
76:
61:
56:
46:
2526:
2266:
Kingdoms and Domains: An Illustrated Guide to the Phyla of Life on Earth
2105:
2045:
Kingdoms and Domains: An Illustrated Guide to the Phyla of Life on Earth
1943:. Vol. 22 (11th ed.). Cambridge University Press. p. 313.
761:
5133:
4999:
4979:
4675:
4650:
4640:
4630:
4586:
4523:
4158:
4134:
4126:
4063:
3977:
3797:
3784:
3717:
3708:
3653:
3578:
2879:
2821:
2796:
2676:
2428:
2404:
2380:
2210:
1967:
1794:
1555:
Species T. arcticus (Adrianov, Malakhov, Tchesunov & Tzetlin, 1989)
580:
that are morphologically almost identical to modern priapulid burrows (
449:
333:
282:
96:
71:
5146:
2960:
2831:
4839:
4831:
4700:
4203:
3937:
3227:
3137:
3124:
2995:
2992:
2781:
1750:
1422:
553:
415:
408:
152:
5036:
2668:
2420:
2202:
390:
Priapulid-like fossils are known at least as far back as the Middle
2301:. Philadelphia, PA: Holt-Saunders International. pp. 873–877.
4748:
4620:
543:
526:
476:
306:
2138:
Meiobenthology: The Microscopic Motile Fauna of Aquatic Sediments
4786:
4278:
2846:
Smith, M. R.; Harvey, T. H. P.; Butterfield, N. J. (July 2015).
1567:
Species T. pardosi (Scmidt-Rhaesa, Panpeng & Yamasaki, 2017)
1564:
Species T. lemburgi (Schmidt-Rhaesa, Rothe & Martínez, 2013)
298:
5040:
4250:
3256:
2964:
1576:
Species T. soyoae (Scmidt-Rhaesa, Panpeng & Yamasaki, 2017)
2226:"Tubiluchus lemburgi, a new species of meiobenthic Priapulida"
5120:
2848:"The macro- and microfossil record of the Cambrian priapulid
2549:
Wennberg, S. A.; Janssen, R.; Budd, G. E. (May–June 2008).
2165:
Multicellular Animals: Order in Nature – System Made by Man
475:, forming part of the body wall. There are no specialized
2600:
Janssen, R.; Wennberg, S. A.; Budd, G. E. (26 May 2009).
1840:
Biological Reviews of the Cambridge Philosophical Society
2894:
Giribet, Gonzalo; Edgecombe, Gregory D. (3 March 2020).
2744:"Penis worms show the evolution of the digestive system"
2230:
Zoologischer Anzeiger - A Journal of Comparative Zoology
2070:"Ancestor of arthropods had the mouth of a penis worm"
1582:
Species T. vanuatensis (Adrianov & Malakhov, 1991)
379:
clade named after the spines covering the introvert (
2477:(6th ed.). New York: McGraw-Hill. p. 454.
356:. Fossil findings show that the mouth design of the
5049:
5012:
4830:
4747:
4699:
4584:
4575:
4522:
4294:
3927:
3808:
3783:
3774:
3750:
3728:
3693:
3652:
3627:
3620:
3605:
3557:
3530:
3515:
3468:
3446:
3426:
3397:
3390:
3363:
3348:
3337:
3300:
3269:
3192:
3153:
3122:
2551:"Early embryonic development of the priapulid worm
1579:
Species T. troglodytes (Todaro & Shirley, 2003)
383:). They feed on slow-moving invertebrates, such as
2657:Transactions of the American Microscopical Society
2409:Transactions of the American Microscopical Society
2263:Margulis, Lynn; Chapman, Michael J. (2009-03-19).
4563:Archaeal Richmond Mine acidophilic nanoorganisms
1459:Species H. higginsi (Shirley & Storch, 1999)
2498:Todaro, M. Antonio; Shirley, Thomas C. (2003).
2755:
2753:
1887:Kungl. Svenska Vetenskapsakademiens Handlingar
1570:Species T. philippinensis (van der Land, 1985)
4262:
2976:
2692:"Deuterostomic development in the protostome
1522:Species P. cnidephorus (Salvini-Plawen, 1973)
8:
2347:
2345:
1558:Species T. australensis (van der Land, 1985)
1536:Species P. tuberculatospinosus (Baird, 1868)
2403:Higgins, Robert P.; Storch, Volker (1991).
1561:Species T. corallicola (van der Land, 1968)
5037:
4581:
4519:
4291:
4287:
4269:
4255:
4247:
3924:
3780:
3756:
3732:
3701:
3624:
3617:
3613:
3536:
3527:
3523:
3452:
3430:
3423:
3394:
3360:
3356:
3345:
3334:
3306:
3277:
3266:
3253:
3165:
3130:
3119:
2983:
2969:
2961:
2602:"The hatching larva of the priapulid worm
1833:
1831:
1829:
430:systems, but the body cavity does contain
107:
20:
2878:
2830:
2820:
2719:
2631:
2621:
2525:
2515:
2379:
2369:
1462:Species H. spinulosus (von Siebold, 1849)
471:configuration with a connection with the
3321:Hemichordata (acorn worms and relatives)
1908:
1906:
1904:
1902:
1900:
1519:Species P. bicaudatus (Danielssen, 1869)
1415:
448:is straight, consisting of an eversible
289:, diminutive), sometimes referred to as
2042:; Chapman, Michael J. (19 March 2009).
1825:
1573:Species T. remanei (van der Land, 1982)
5268:Extant Pennsylvanian first appearances
3315:Echinodermata (starfish and relatives)
3285:Xenacoelomorpha (acoels and relatives)
2322:Schmidt-Rhaesa, Andreas (2012-12-21).
1516:Species P. australis (de Guerne, 1886)
2292:
2290:
2288:
2286:
434:amoebocytes and cells containing the
340:, they were once placed in the taxon
7:
3586:Acanthocephala (thorny-headed worms)
1609:Species M. cirratus (Malakhov, 1979)
1530:Species P. abyssorum (Menzies, 1959)
2328:. Vol. 11. Walter de Gruyter.
1612:Species M. tentaculatus (Por, 1973)
1533:Species P. caudatus (Lamarck, 1816)
1413:There are 22 known extant species:
1266:
1239:
1181:
1174:
1141:
1111:
1022:
1012:
1002:
973:
947:
919:
877:
870:
780:
750:
691:
681:
625:
615:
605:
586:) officially mark the start of the
568:are known from the Middle Cambrian
261:
3183:Cnidaria (jellyfish and relatives)
1852:10.1111/j.1469-185X.1999.tb00046.x
1480:Species M. fijiensis (Morse, 1981)
418:; it is probably a blood-space or
305:may resemble the shape of a human
16:Phylum of unsegmented marine worms
14:
1508:Species A. horridus (Théel, 1911)
986:(Spiny crown worms; Mud dragons)
959:Conway Morris & Robinson 1986
375:, with which they constitute the
4227:Phyla with ≥1000 extant species
2571:10.1111/j.1525-142X.2008.00241.x
2460:10.1111/j.1744-7410.2010.00185.x
1913:
810:
790:
760:
721:
701:
655:
635:
129:
1409:List of bilateral animal orders
3414:Nematomorpha (horsehair worms)
2900:. Princeton University Press.
1766:Huang, Vannier & Chen 2004
1:
2946:"Evolution of the penis worm"
2897:The Invertebrate Tree of Life
2135:Giere, Olav (November 2008).
1713:Walcott 1911 non Hemsley 1884
1493:(assigned its own order by )
4026:Echinozoans inc. sea urchins
2475:Biology of the Invertebrates
1881:Théel, Hjalmar (1905–1906).
1724:Adrianov & Malakhov 1995
1639:Adrianov & Malakhov 1995
1491:Adrianov & Malakhov 1995
905:Adrianov & Malakhov 1995
502:Reproduction and development
4083:Chelicerates inc. arachnids
3823:Phoronida (horseshoe worms)
3638:Platyhelminthes (flatworms)
3549:Gnathostomulida (jaw worms)
3438:Loricifera (corset animals)
2559:Evolution & Development
1252:Koren & Danielssen 1875
5284:
3973:Medusozoans inc. jellyfish
3719:Annelida (segmented worms)
3544:Chaetognatha (arrow worms)
3460:Onychophora (velvet worms)
2504:Italian Journal of Zoology
2371:10.1007/s00435-023-00617-4
1426:, a prehistoric priapulid.
1406:
4518:
4290:
4286:
4281:phyla/divisions by domain
4223:
4021:Asterozoans inc. starfish
3923:
3916:
3867:
3818:Brachiopoda (lamp shells)
3799:Ectoprocta (moss animals)
3759:
3735:
3704:
3644:Gastrotricha (hairybacks)
3616:
3539:
3526:
3455:
3433:
3422:
3373:Kinorhyncha (mud dragons)
3359:
3333:
3309:
3280:
3265:
3252:
3217:
3168:
3145:Ctenophora (comb jellies)
3133:
3118:
3002:
2721:10.1016/j.cub.2012.09.037
2517:10.1080/11250000309356499
2250:10.1016/j.jcz.2013.08.004
2015:10.1016/j.jcz.2022.11.013
1471:Order Meiopriapulomorpha
1291:
1271:
1264:
1244:
1237:
1207:
1186:
1179:
1172:
1149:
1139:
1119:
1109:
1068:
1048:
1027:
1020:
1010:
1000:
978:
971:
952:
945:
924:
917:
898:
882:
875:
805:
785:
778:
755:
748:
716:
696:
689:
679:
650:
630:
623:
613:
259:
254:
126:Scientific classification
124:
115:
106:
30:Late Pennsylvanian–Recent
23:
3579:Rotifera (wheel animals)
3378:Priapulida (penis worms)
2473:Pechenik, J. A. (2009).
2162:Ax, Peter (2003-04-08).
557:, Cambrian). From Smith
4491:Thermodesulfobacteriota
3793:Entoprocta or Kamptozoa
3765:Nemertea (ribbon worms)
3486:Tardigrada (waterbears)
3479:Arthropoda (arthropods)
1940:Encyclopædia Britannica
1927:Shipley, Arthur Everett
1505:Genus Acanthopriapulus
1474:Family Meiopriapulidae
512:Meiopriapulus fijiensis
3968:Anthozoans inc. corals
3667:Dicyemida or Rhombozoa
2604:Halicryptus spinulosus
2444:Tubiluchus troglodytes
2297:Barnes, R. D. (1982).
1602:Por & Bromley 1974
1427:
562:
551:of a priapulid tooth (
541:
519:have been maintained.
348:, which also includes
323:Halicryptus spinulosus
297:of unsegmented marine
5207:Paleobiology Database
4719:Neocallimastigomycota
4098:Hexapods inc. insects
3408:Nematoda (roundworms)
2954:University of Bristol
2623:10.1186/1742-9994-6-8
1995:Zoologischer Anzeiger
1489:Order Priapulomorpha
1419:
566:Stem-group priapulids
547:
530:
4384:Coprothermobacterota
3291:Chordata (chordates)
2610:Frontiers in Zoology
2448:Invertebrate Biology
2299:Invertebrate Zoology
2191:Invertebrate Biology
1477:Genus Meiopriapulus
277:, from Gr. πριάπος,
3741:Mollusca (molluscs)
3226:of the animal root
2871:2015Palgy..58..705S
2813:2017Palgy..60..117S
2774:2010Geo....38..711V
2712:2012CBio...22.2161M
2325:Handbook of Zoology
2242:2013ZooAn.253..158S
2106:10.1038/nature06614
2098:2008Natur.452..745D
2007:2023ZooAn.302..113K
1513:Genus Priapulopsis
1452:Salvini-Plawen 1974
1443:Salvini-Plawen 1974
485:The priapulids are
436:respiratory pigment
4714:Blastocladiomycota
3954:Calcareous sponges
3139:Porifera (sponges)
2880:10.1111/pala.12168
2822:10.1111/pala.12273
2694:Priapulus caudatus
2553:Priapulus caudatus
2269:. Academic Press.
2048:. Academic Press.
1968:10.1007/BF00017494
1810:Conway Morris 1977
1735:Conway Morris 1977
1702:Conway Morris 1977
1670:Conway Morris 1977
1659:Conway Morris 1977
1648:Conway Morris 1977
1456:Genus Halicryptus
1428:
1007:Meiopriapulomorpha
864:Internal phylogeny
599:External phylogeny
563:
542:
508:Priapulus caudatus
327:Priapulus caudatus
118:Priapulus caudatus
5245:
5244:
5194:Open Tree of Life
5043:Taxon identifiers
5034:
5033:
5030:
5029:
5008:
5007:
4571:
4570:
4514:
4513:
4506:Verrucomicrobiota
4244:
4243:
4219:
4218:
3912:
3911:
3908:
3907:
3863:
3862:
3859:
3858:
3855:
3854:
3851:
3850:
3847:
3846:
3843:
3842:
3839:
3838:
3835:
3834:
3831:
3830:
3689:
3688:
3685:
3684:
3601:
3600:
3597:
3596:
3511:
3510:
3507:
3506:
3503:
3502:
3499:
3498:
3495:
3494:
3386:
3385:
3329:
3328:
3248:
3247:
3213:
3212:
3209:
3208:
2907:978-0-691-17025-1
2706:(22): 2161–2166.
2484:978-0-07-302826-2
2335:978-3-11-027253-6
2308:978-0-03-056747-6
2276:978-0-08-092014-6
2175:978-3-540-00146-1
2148:978-3-540-68661-3
2092:(7188): 745–749.
2055:978-0-08-092014-6
1811:
1800:
1789:
1778:
1777:Luo & Hu 1999
1767:
1756:
1745:
1736:
1725:
1714:
1703:
1682:
1671:
1660:
1649:
1640:
1603:
1599:Chaetostephanidae
1552:Genus Tubiluchus
1549:
1548:van der Land 1970
1502:
1492:
1453:
1444:
1399:
1398:
1390:
1389:
1381:
1380:
1372:
1371:
1363:
1362:
1354:
1353:
1345:
1344:
1336:
1335:
1327:
1326:
1318:
1317:
1309:
1308:
1300:
1280:
1279:van der Land 1970
1253:
1226:
1225:
1217:
1196:
1158:
1128:
1095:
1094:
1086:
1085:
1077:
1076:van der Land 1968
1057:
1037:
985:
960:
934:
906:
886:Archaeopriapulida
860:
859:
856:>529 mya
850:
849:
841:
840:
832:
831:
823:
822:
734:
733:
668:
667:
583:Treptichnus pedum
540:. Middle Cambrian
533:Ottoia tricuspida
268:
267:
250:
5275:
5238:
5237:
5225:
5224:
5215:
5214:
5202:
5201:
5189:
5188:
5176:
5175:
5163:
5162:
5150:
5149:
5137:
5136:
5124:
5123:
5111:
5110:
5098:
5097:
5085:
5084:
5083:
5070:
5069:
5068:
5038:
4782:Anthocerotophyta
4661:Hemimastigophora
4582:
4553:Nitrososphaerota
4520:
4496:Thermomicrobiota
4436:Kiritimatiellota
4431:Ignavibacteriota
4396:Deferribacterota
4359:Campylobacterota
4344:Bdellovibrionota
4292:
4288:
4271:
4264:
4257:
4248:
3925:
3881:
3781:
3757:
3733:
3702:
3698:
3625:
3618:
3614:
3610:
3537:
3528:
3524:
3520:
3453:
3431:
3424:
3395:
3361:
3357:
3353:
3346:
3342:
3335:
3307:
3278:
3274:
3267:
3254:
3231:
3166:
3131:
3127:
3120:
3031:
3011:
2985:
2978:
2971:
2962:
2957:
2932:
2929:
2923:
2918:
2912:
2911:
2891:
2885:
2884:
2882:
2856:
2843:
2837:
2836:
2834:
2824:
2792:
2786:
2785:
2782:10.1130/G30829.1
2757:
2748:
2747:
2740:
2734:
2733:
2723:
2687:
2681:
2680:
2652:
2646:
2645:
2635:
2625:
2597:
2591:
2590:
2546:
2540:
2539:
2529:
2519:
2495:
2489:
2488:
2470:
2464:
2463:
2439:
2433:
2432:
2400:
2394:
2393:
2383:
2373:
2349:
2340:
2339:
2319:
2313:
2312:
2294:
2281:
2280:
2260:
2254:
2253:
2221:
2215:
2214:
2186:
2180:
2179:
2159:
2153:
2152:
2132:
2126:
2125:
2080:
2074:
2073:
2066:
2060:
2059:
2036:
2030:
2025:
2019:
2018:
1986:
1980:
1979:
1951:
1945:
1944:
1919:
1917:
1916:
1910:
1895:
1894:
1878:
1872:
1871:
1835:
1809:
1798:
1787:
1776:
1765:
1754:
1743:
1734:
1723:
1712:
1701:
1680:
1669:
1658:
1647:
1638:
1606:Genus Maccabeus
1601:
1547:
1527:Genus Priapulus
1500:
1490:
1451:
1442:
1440:Halicryptomorpha
1420:Illustration of
1298:
1278:
1275:Acanthopriapulus
1267:
1251:
1240:
1215:
1194:
1182:
1175:
1157:von Siebold 1849
1156:
1142:
1126:
1112:
1075:
1055:
1035:
1023:
1013:
1003:
983:
974:
958:
948:
932:
920:
904:
878:
871:
814:
794:
781:
764:
751:
725:
705:
692:
682:
659:
639:
626:
616:
606:
446:alimentary canal
311:hydrogen sulfide
248:
134:
133:
111:
101:
38:
31:
27:Temporal range:
21:
5283:
5282:
5278:
5277:
5276:
5274:
5273:
5272:
5263:Ecdysozoa phyla
5248:
5247:
5246:
5241:
5233:
5228:
5220:
5218:
5210:
5205:
5197:
5192:
5184:
5179:
5171:
5166:
5158:
5153:
5145:
5140:
5132:
5127:
5119:
5114:
5106:
5101:
5093:
5088:
5079:
5078:
5073:
5064:
5063:
5058:
5045:
5035:
5026:
5004:
4955:Gnathostomulida
4860:Xenacoelomorpha
4826:
4822:Flowering plant
4777:Marchantiophyta
4743:
4709:Chytridiomycota
4695:
4567:
4510:
4466:Planctomycetota
4426:Gemmatimonadota
4411:Elusimicrobiota
4304:Acidobacteriota
4282:
4275:
4245:
4240:
4215:
4141:Phylactolaemata
3929:
3919:
3918:
3904:
3895:Xenambulacraria
3871:
3827:
3804:
3770:
3752:Kryptotrochozoa
3746:
3724:
3694:
3681:
3672:Monoblastozoa (
3648:
3606:
3593:
3565:Micrognathozoa
3553:
3516:
3491:
3464:
3442:
3418:
3382:
3349:
3338:
3325:
3296:
3270:
3261:
3244:
3221:
3205:
3188:
3157:
3149:
3123:
3114:
3113:
3029:
3007:
2998:
2989:
2944:
2941:
2936:
2935:
2930:
2926:
2919:
2915:
2908:
2893:
2892:
2888:
2854:
2845:
2844:
2840:
2794:
2793:
2789:
2759:
2758:
2751:
2742:
2741:
2737:
2700:Current Biology
2689:
2688:
2684:
2669:10.2307/3226738
2654:
2653:
2649:
2599:
2598:
2594:
2548:
2547:
2543:
2497:
2496:
2492:
2485:
2472:
2471:
2467:
2446:(Priapulida)".
2441:
2440:
2436:
2421:10.2307/3226738
2402:
2401:
2397:
2351:
2350:
2343:
2336:
2321:
2320:
2316:
2309:
2296:
2295:
2284:
2277:
2262:
2261:
2257:
2223:
2222:
2218:
2203:10.2307/3227009
2188:
2187:
2183:
2176:
2161:
2160:
2156:
2149:
2134:
2133:
2129:
2082:
2081:
2077:
2068:
2067:
2063:
2056:
2038:
2037:
2033:
2026:
2022:
1988:
1987:
1983:
1953:
1952:
1948:
1925:
1914:
1912:
1911:
1898:
1880:
1879:
1875:
1837:
1836:
1827:
1822:
1692:Palaeoscolecida
1625:
1411:
1405:
1400:
1391:
1382:
1373:
1364:
1355:
1346:
1337:
1328:
1319:
1310:
1227:
1212:Xiaoheiqingella
1096:
1087:
1036:Han et al. 2004
956:Palaeoscolecida
866:
861:
851:
842:
833:
824:
735:
669:
601:
596:
525:
504:
422:. There are no
404:
275:priapulid worms
247:
128:
102:
100:
99:
94:
89:
84:
79:
74:
69:
64:
59:
54:
49:
44:
32:
29:
28:
25:
17:
12:
11:
5:
5281:
5279:
5271:
5270:
5265:
5260:
5250:
5249:
5243:
5242:
5240:
5239:
5226:
5216:
5203:
5190:
5177:
5164:
5151:
5138:
5125:
5112:
5099:
5086:
5071:
5055:
5053:
5047:
5046:
5041:
5032:
5031:
5028:
5027:
5020:
5018:
5015:Incertae sedis
5010:
5009:
5006:
5005:
5003:
5002:
4997:
4992:
4987:
4982:
4977:
4972:
4967:
4962:
4960:Micrognathozoa
4957:
4952:
4950:Acanthocephala
4947:
4942:
4937:
4932:
4927:
4922:
4917:
4912:
4907:
4902:
4897:
4892:
4887:
4882:
4877:
4872:
4867:
4862:
4857:
4852:
4847:
4842:
4836:
4834:
4828:
4827:
4825:
4824:
4819:
4814:
4809:
4804:
4799:
4794:
4792:Lycopodiophyta
4789:
4784:
4779:
4774:
4769:
4764:
4759:
4753:
4751:
4745:
4744:
4742:
4741:
4736:
4731:
4726:
4721:
4716:
4711:
4705:
4703:
4697:
4696:
4694:
4693:
4688:
4683:
4678:
4673:
4668:
4663:
4658:
4653:
4648:
4643:
4638:
4633:
4628:
4623:
4618:
4613:
4608:
4606:Ancyromonadida
4603:
4598:
4592:
4590:
4579:
4573:
4572:
4569:
4568:
4566:
4565:
4560:
4558:Thermoproteota
4555:
4550:
4543:
4536:
4528:
4526:
4516:
4515:
4512:
4511:
4509:
4508:
4503:
4498:
4493:
4488:
4483:
4478:
4473:
4471:Pseudomonadota
4468:
4463:
4458:
4453:
4448:
4446:Mycoplasmatota
4443:
4441:Lentisphaerota
4438:
4433:
4428:
4423:
4421:Fusobacteriota
4418:
4416:Fibrobacterota
4413:
4408:
4403:
4398:
4393:
4386:
4381:
4376:
4371:
4366:
4361:
4356:
4351:
4346:
4341:
4336:
4331:
4326:
4321:
4319:Armatimonadota
4316:
4311:
4309:Actinomycetota
4306:
4300:
4298:
4284:
4283:
4276:
4274:
4273:
4266:
4259:
4251:
4242:
4241:
4239:
4238:
4231:
4224:
4221:
4220:
4217:
4216:
4214:
4213:
4212:
4211:
4206:
4201:
4196:
4191:
4179:
4178:
4177:
4172:
4167:
4155:
4154:
4153:
4148:
4143:
4131:
4130:
4129:
4124:
4119:
4114:
4106:Platyhelminths
4102:
4101:
4100:
4095:
4090:
4085:
4073:
4072:
4071:
4066:
4061:
4049:
4048:
4047:
4042:
4030:
4029:
4028:
4023:
4018:
4006:
4005:
4004:
3999:
3994:
3982:
3981:
3980:
3975:
3970:
3958:
3957:
3956:
3951:
3946:
3933:
3931:
3921:
3920:
3917:
3914:
3913:
3910:
3909:
3906:
3905:
3903:
3902:
3900:Centroneuralia
3897:
3892:
3887:
3882:
3868:
3865:
3864:
3861:
3860:
3857:
3856:
3853:
3852:
3849:
3848:
3845:
3844:
3841:
3840:
3837:
3836:
3833:
3832:
3829:
3828:
3826:
3825:
3820:
3814:
3812:
3806:
3805:
3803:
3802:
3795:
3789:
3787:
3778:
3772:
3771:
3769:
3768:
3760:
3754:
3748:
3747:
3745:
3744:
3736:
3730:
3726:
3725:
3723:
3722:
3715:
3705:
3699:
3696:Lophotrochozoa
3691:
3690:
3687:
3686:
3683:
3682:
3680:
3679:
3669:
3664:
3658:
3656:
3650:
3649:
3647:
3646:
3641:
3633:
3631:
3622:
3611:
3608:Platytrochozoa
3603:
3602:
3599:
3598:
3595:
3594:
3592:
3591:
3590:
3589:
3582:
3570:
3567:(Limnognathia)
3561:
3559:
3555:
3554:
3552:
3551:
3546:
3540:
3534:
3521:
3513:
3512:
3509:
3508:
3505:
3504:
3501:
3500:
3497:
3496:
3493:
3492:
3490:
3489:
3482:
3474:
3472:
3466:
3465:
3463:
3462:
3456:
3450:
3444:
3443:
3441:
3440:
3434:
3428:
3420:
3419:
3417:
3416:
3411:
3403:
3401:
3392:
3388:
3387:
3384:
3383:
3381:
3380:
3375:
3369:
3367:
3354:
3343:
3331:
3330:
3327:
3326:
3324:
3323:
3318:
3310:
3304:
3298:
3297:
3295:
3294:
3287:
3281:
3275:
3263:
3262:
3257:
3250:
3249:
3246:
3245:
3243:
3242:
3237:
3232:
3218:
3215:
3214:
3211:
3210:
3207:
3206:
3204:
3203:
3199:
3197:
3196:(Triploblasts)
3190:
3189:
3187:
3186:
3179:
3177:and relatives)
3169:
3163:
3151:
3150:
3148:
3147:
3142:
3134:
3128:
3116:
3115:
3112:
3111:
3110:
3109:
3108:
3107:
3104:Mesomycetozoea
3101:
3096:
3086:
3076:
3075:
3074:
3069:
3064:
3059:
3054:
3053:
3052:
3040:Diaphoretickes
3037:
3032:
3027:
3022:
3017:
3012:
3004:
3003:
3000:
2999:
2990:
2988:
2987:
2980:
2973:
2965:
2959:
2958:
2950:Press Releases
2940:
2939:External links
2937:
2934:
2933:
2924:
2913:
2906:
2886:
2865:(4): 705–721.
2838:
2807:(1): 117–140.
2787:
2768:(8): 711–714.
2749:
2735:
2682:
2647:
2592:
2565:(3): 326–338.
2541:
2490:
2483:
2465:
2434:
2395:
2364:(4): 411–421.
2341:
2334:
2314:
2307:
2282:
2275:
2255:
2236:(2): 158–163.
2216:
2197:(4): 404–413.
2181:
2174:
2154:
2147:
2127:
2075:
2061:
2054:
2040:Margulis, Lynn
2031:
2020:
1981:
1946:
1935:Chisholm, Hugh
1896:
1873:
1824:
1823:
1821:
1818:
1817:
1816:
1815:
1814:
1813:
1812:
1801:
1781:
1780:
1779:
1759:
1758:
1757:
1737:
1717:
1716:
1715:
1688:
1687:
1686:
1685:
1684:
1683:
1663:
1662:
1661:
1624:
1623:Extinct groups
1621:
1620:
1619:
1618:
1617:
1616:
1615:
1614:
1613:
1610:
1589:
1588:
1587:
1586:
1585:
1584:
1583:
1580:
1577:
1574:
1571:
1568:
1565:
1562:
1559:
1556:
1541:
1540:
1539:
1538:
1537:
1534:
1531:
1525:
1524:
1523:
1520:
1517:
1511:
1510:
1509:
1487:
1486:
1485:
1484:
1483:
1482:
1481:
1469:
1468:
1467:
1466:
1465:
1464:
1463:
1460:
1404:
1403:Classification
1401:
1397:
1396:
1393:
1392:
1388:
1387:
1384:
1383:
1379:
1378:
1375:
1374:
1370:
1369:
1366:
1365:
1361:
1360:
1357:
1356:
1352:
1351:
1348:
1347:
1343:
1342:
1339:
1338:
1334:
1333:
1330:
1329:
1325:
1324:
1321:
1320:
1316:
1315:
1312:
1311:
1307:
1306:
1303:
1302:
1290:
1287:
1286:
1283:
1282:
1270:
1265:
1263:
1260:
1259:
1256:
1255:
1243:
1238:
1236:
1233:
1232:
1229:
1228:
1224:
1223:
1220:
1219:
1206:
1203:
1202:
1199:
1198:
1185:
1180:
1178:
1173:
1171:
1165:
1164:
1161:
1160:
1148:
1140:
1138:
1135:
1134:
1131:
1130:
1118:
1110:
1108:
1106:Priapulimorpha
1102:
1101:
1098:
1097:
1093:
1092:
1089:
1088:
1084:
1083:
1080:
1079:
1067:
1064:
1063:
1060:
1059:
1047:
1044:
1043:
1040:
1039:
1032:Paratubiluchus
1026:
1021:
1019:
1011:
1009:
1001:
999:
993:
992:
989:
988:
977:
972:
970:
967:
966:
963:
962:
951:
946:
944:
941:
940:
937:
936:
923:
918:
916:
913:
912:
909:
908:
897:
894:
893:
890:
889:
881:
876:
874:
869:
865:
862:
858:
857:
853:
852:
848:
847:
844:
843:
839:
838:
835:
834:
830:
829:
826:
825:
821:
820:
817:
816:
804:
801:
800:
797:
796:
784:
779:
777:
771:
770:
767:
766:
754:
749:
747:
741:
740:
737:
736:
732:
731:
728:
727:
715:
712:
711:
708:
707:
695:
690:
688:
680:
678:
675:
674:
671:
670:
666:
665:
662:
661:
649:
646:
645:
642:
641:
629:
624:
622:
614:
612:
604:
600:
597:
595:
592:
524:
521:
503:
500:
491:protonephridia
461:nervous system
403:
400:
332:Together with
266:
265:
257:
256:
252:
251:
242:
238:
237:
232:
225:
224:
219:
215:
214:
209:
205:
204:
199:
192:
191:
186:
179:
178:
173:
166:
165:
160:
156:
155:
150:
146:
145:
140:
136:
135:
122:
121:
113:
112:
104:
103:
95:
90:
85:
80:
75:
70:
65:
60:
55:
50:
45:
40:
39:
37:from Cambrian)
26:
15:
13:
10:
9:
6:
4:
3:
2:
5280:
5269:
5266:
5264:
5261:
5259:
5256:
5255:
5253:
5236:
5231:
5227:
5223:
5217:
5213:
5208:
5204:
5200:
5195:
5191:
5187:
5182:
5178:
5174:
5169:
5165:
5161:
5156:
5152:
5148:
5143:
5139:
5135:
5130:
5126:
5122:
5117:
5113:
5109:
5104:
5100:
5096:
5091:
5087:
5082:
5076:
5072:
5067:
5061:
5057:
5056:
5054:
5052:
5048:
5044:
5039:
5025:
5024:
5019:
5017:
5016:
5011:
5001:
4998:
4996:
4993:
4991:
4988:
4986:
4983:
4981:
4978:
4976:
4973:
4971:
4968:
4966:
4963:
4961:
4958:
4956:
4953:
4951:
4948:
4946:
4943:
4941:
4938:
4936:
4933:
4931:
4928:
4926:
4923:
4921:
4918:
4916:
4913:
4911:
4908:
4906:
4903:
4901:
4898:
4896:
4893:
4891:
4888:
4886:
4883:
4881:
4878:
4876:
4873:
4871:
4868:
4866:
4863:
4861:
4858:
4856:
4853:
4851:
4848:
4846:
4843:
4841:
4838:
4837:
4835:
4833:
4829:
4823:
4820:
4818:
4815:
4813:
4810:
4808:
4805:
4803:
4800:
4798:
4795:
4793:
4790:
4788:
4785:
4783:
4780:
4778:
4775:
4773:
4770:
4768:
4765:
4763:
4760:
4758:
4755:
4754:
4752:
4750:
4746:
4740:
4739:Basidiomycota
4737:
4735:
4732:
4730:
4727:
4725:
4724:Glomeromycota
4722:
4720:
4717:
4715:
4712:
4710:
4707:
4706:
4704:
4702:
4698:
4692:
4689:
4687:
4686:Stramenopiles
4684:
4682:
4679:
4677:
4674:
4672:
4669:
4667:
4664:
4662:
4659:
4657:
4654:
4652:
4649:
4647:
4644:
4642:
4639:
4637:
4634:
4632:
4629:
4627:
4624:
4622:
4619:
4617:
4614:
4612:
4611:Apusomonadida
4609:
4607:
4604:
4602:
4599:
4597:
4594:
4593:
4591:
4588:
4583:
4580:
4578:
4574:
4564:
4561:
4559:
4556:
4554:
4551:
4548:
4547:Nanoarchaeota
4544:
4541:
4537:
4534:
4533:Euryarchaeota
4530:
4529:
4527:
4525:
4521:
4517:
4507:
4504:
4502:
4499:
4497:
4494:
4492:
4489:
4487:
4484:
4482:
4481:Spirochaetota
4479:
4477:
4476:Rhodothermota
4474:
4472:
4469:
4467:
4464:
4462:
4459:
4457:
4454:
4452:
4449:
4447:
4444:
4442:
4439:
4437:
4434:
4432:
4429:
4427:
4424:
4422:
4419:
4417:
4414:
4412:
4409:
4407:
4406:Dictyoglomota
4404:
4402:
4399:
4397:
4394:
4391:
4390:Cyanobacteria
4387:
4385:
4382:
4380:
4379:Chrysiogenota
4377:
4375:
4374:Chloroflexota
4372:
4370:
4367:
4365:
4362:
4360:
4357:
4355:
4354:Calditrichota
4352:
4350:
4349:Caldisericota
4347:
4345:
4342:
4340:
4337:
4335:
4332:
4330:
4327:
4325:
4324:Atribacterota
4322:
4320:
4317:
4315:
4312:
4310:
4307:
4305:
4302:
4301:
4299:
4297:
4293:
4289:
4285:
4280:
4272:
4267:
4265:
4260:
4258:
4253:
4252:
4249:
4236:
4235:dubious phyla
4232:
4230:
4226:
4225:
4222:
4210:
4207:
4205:
4202:
4200:
4197:
4195:
4192:
4190:
4187:
4186:
4185:
4184:
4180:
4176:
4173:
4171:
4168:
4166:
4163:
4162:
4161:
4160:
4156:
4152:
4149:
4147:
4144:
4142:
4139:
4138:
4137:
4136:
4132:
4128:
4125:
4123:
4120:
4118:
4115:
4113:
4110:
4109:
4108:
4107:
4103:
4099:
4096:
4094:
4091:
4089:
4086:
4084:
4081:
4080:
4079:
4078:
4074:
4070:
4067:
4065:
4062:
4060:
4057:
4056:
4055:
4054:
4050:
4046:
4043:
4041:
4038:
4037:
4036:
4035:
4034:Hemichordates
4031:
4027:
4024:
4022:
4019:
4017:
4014:
4013:
4012:
4011:
4007:
4003:
4000:
3998:
3995:
3993:
3990:
3989:
3988:
3987:
3983:
3979:
3976:
3974:
3971:
3969:
3966:
3965:
3964:
3963:
3959:
3955:
3952:
3950:
3949:Glass sponges
3947:
3945:
3942:
3941:
3940:
3939:
3935:
3934:
3932:
3926:
3922:
3915:
3901:
3898:
3896:
3893:
3891:
3890:Deuterostomia
3888:
3886:
3883:
3879:
3876:of Bilateria
3875:
3870:
3869:
3866:
3824:
3821:
3819:
3816:
3815:
3813:
3811:
3807:
3801:
3800:
3796:
3794:
3791:
3790:
3788:
3786:
3782:
3779:
3777:
3773:
3767:
3766:
3762:
3761:
3758:
3755:
3753:
3749:
3743:
3742:
3738:
3737:
3734:
3731:
3727:
3721:
3720:
3716:
3714:
3712:
3709:Cycliophora (
3707:
3706:
3703:
3700:
3697:
3692:
3677:
3675:
3670:
3668:
3665:
3663:
3660:
3659:
3657:
3655:
3651:
3645:
3642:
3640:
3639:
3635:
3634:
3632:
3630:
3626:
3623:
3619:
3615:
3612:
3609:
3604:
3588:
3587:
3583:
3581:
3580:
3576:
3575:
3574:
3571:
3569:
3568:
3563:
3562:
3560:
3556:
3550:
3547:
3545:
3542:
3541:
3538:
3535:
3533:
3529:
3525:
3522:
3519:
3514:
3488:
3487:
3483:
3481:
3480:
3476:
3475:
3473:
3471:
3467:
3461:
3458:
3457:
3454:
3451:
3449:
3448:Panarthropoda
3445:
3439:
3436:
3435:
3432:
3429:
3425:
3421:
3415:
3412:
3410:
3409:
3405:
3404:
3402:
3400:
3396:
3393:
3389:
3379:
3376:
3374:
3371:
3370:
3368:
3366:
3362:
3358:
3355:
3352:
3347:
3344:
3341:
3336:
3332:
3322:
3319:
3317:
3316:
3312:
3311:
3308:
3305:
3303:
3299:
3293:
3292:
3288:
3286:
3283:
3282:
3279:
3276:
3273:
3268:
3264:
3260:
3255:
3251:
3241:
3238:
3236:
3233:
3229:
3225:
3220:
3219:
3216:
3201:
3200:
3198:
3195:
3191:
3185:
3184:
3180:
3178:
3176:
3171:
3170:
3167:
3164:
3161:
3156:
3152:
3146:
3143:
3141:
3140:
3136:
3135:
3132:
3129:
3126:
3121:
3117:
3105:
3102:
3100:
3097:
3095:
3092:
3091:
3090:
3087:
3085:
3082:
3081:
3080:
3077:
3073:
3070:
3068:
3067:Stramenopiles
3065:
3063:
3060:
3058:
3055:
3051:
3048:
3047:
3046:
3043:
3042:
3041:
3038:
3036:
3033:
3030:(major groups
3028:
3026:
3023:
3021:
3018:
3016:
3013:
3010:
3006:
3005:
3001:
2997:
2994:
2986:
2981:
2979:
2974:
2972:
2967:
2966:
2963:
2956:. 2006-08-09.
2955:
2951:
2947:
2943:
2942:
2938:
2928:
2925:
2922:
2917:
2914:
2909:
2903:
2899:
2898:
2890:
2887:
2881:
2876:
2872:
2868:
2864:
2860:
2859:Palaeontology
2853:
2851:
2842:
2839:
2833:
2828:
2823:
2818:
2814:
2810:
2806:
2802:
2801:Palaeontology
2798:
2791:
2788:
2783:
2779:
2775:
2771:
2767:
2763:
2756:
2754:
2750:
2745:
2739:
2736:
2731:
2727:
2722:
2717:
2713:
2709:
2705:
2701:
2697:
2695:
2686:
2683:
2678:
2674:
2670:
2666:
2662:
2658:
2651:
2648:
2643:
2639:
2634:
2629:
2624:
2619:
2615:
2611:
2607:
2605:
2596:
2593:
2588:
2584:
2580:
2576:
2572:
2568:
2564:
2560:
2556:
2554:
2545:
2542:
2537:
2533:
2528:
2523:
2518:
2513:
2509:
2505:
2501:
2494:
2491:
2486:
2480:
2476:
2469:
2466:
2461:
2457:
2453:
2449:
2445:
2438:
2435:
2430:
2426:
2422:
2418:
2414:
2410:
2406:
2399:
2396:
2391:
2387:
2382:
2377:
2372:
2367:
2363:
2359:
2358:Zoomorphology
2355:
2348:
2346:
2342:
2337:
2331:
2327:
2326:
2318:
2315:
2310:
2304:
2300:
2293:
2291:
2289:
2287:
2283:
2278:
2272:
2268:
2267:
2259:
2256:
2251:
2247:
2243:
2239:
2235:
2231:
2227:
2220:
2217:
2212:
2208:
2204:
2200:
2196:
2192:
2185:
2182:
2177:
2171:
2167:
2166:
2158:
2155:
2150:
2144:
2140:
2139:
2131:
2128:
2123:
2119:
2115:
2111:
2107:
2103:
2099:
2095:
2091:
2087:
2079:
2076:
2071:
2065:
2062:
2057:
2051:
2047:
2046:
2041:
2035:
2032:
2029:
2024:
2021:
2016:
2012:
2008:
2004:
2000:
1996:
1992:
1985:
1982:
1977:
1973:
1969:
1965:
1961:
1957:
1956:Hydrobiologia
1950:
1947:
1942:
1941:
1936:
1932:
1928:
1923:
1922:public domain
1909:
1907:
1905:
1903:
1901:
1897:
1892:
1888:
1884:
1877:
1874:
1869:
1865:
1861:
1857:
1853:
1849:
1846:(2): 253–95.
1845:
1841:
1834:
1832:
1830:
1826:
1819:
1808:
1807:
1802:
1797:
1796:
1791:
1790:
1786:
1782:
1775:
1774:
1769:
1768:
1764:
1760:
1753:
1752:
1747:
1746:
1742:
1738:
1733:
1732:
1727:
1726:
1722:
1718:
1711:
1710:
1705:
1704:
1700:
1696:
1695:
1694:
1693:
1679:
1678:
1673:
1672:
1668:
1664:
1657:
1656:
1651:
1650:
1646:
1645:Ancalagonidae
1642:
1641:
1637:
1633:
1632:
1631:
1630:
1622:
1611:
1608:
1607:
1605:
1604:
1600:
1596:
1595:
1594:
1593:Seticoronaria
1590:
1581:
1578:
1575:
1572:
1569:
1566:
1563:
1560:
1557:
1554:
1553:
1551:
1550:
1546:
1542:
1535:
1532:
1529:
1528:
1526:
1521:
1518:
1515:
1514:
1512:
1507:
1506:
1504:
1503:
1499:
1495:
1494:
1488:
1479:
1478:
1476:
1475:
1473:
1472:
1470:
1461:
1458:
1457:
1455:
1454:
1450:
1449:Halicryptidae
1446:
1445:
1441:
1437:
1436:
1435:
1433:
1425:
1424:
1418:
1414:
1410:
1402:
1395:
1394:
1386:
1385:
1377:
1376:
1368:
1367:
1359:
1358:
1350:
1349:
1341:
1340:
1332:
1331:
1323:
1322:
1314:
1313:
1305:
1304:
1301:
1297:
1296:
1289:
1288:
1285:
1284:
1281:
1277:
1276:
1269:
1268:
1262:
1261:
1258:
1257:
1254:
1250:
1249:
1242:
1241:
1235:
1234:
1231:
1230:
1222:
1221:
1218:
1214:
1213:
1205:
1204:
1201:
1200:
1197:
1193:
1192:
1184:
1183:
1177:
1176:
1170:
1167:
1166:
1163:
1162:
1159:
1155:
1154:
1147:
1146:Halicryptidae
1144:
1143:
1137:
1136:
1133:
1132:
1129:
1125:
1124:
1117:
1114:
1113:
1107:
1104:
1103:
1100:
1099:
1091:
1090:
1082:
1081:
1078:
1074:
1073:
1066:
1065:
1062:
1061:
1058:
1054:
1053:
1052:Meiopriapulus
1046:
1045:
1042:
1041:
1038:
1034:
1033:
1025:
1024:
1018:
1015:
1014:
1008:
1005:
1004:
998:
995:
994:
991:
990:
987:
984:Reinhard 1887
982:
976:
975:
969:
968:
965:
964:
961:
957:
950:
949:
943:
942:
939:
938:
935:
931:
930:
922:
921:
915:
914:
911:
910:
907:
903:
896:
895:
892:
891:
888:
887:
880:
879:
873:
872:
868:
863:
855:
854:
846:
845:
837:
836:
828:
827:
819:
818:
815:
813:
809:
803:
802:
799:
798:
795:
793:
789:
783:
782:
776:
773:
772:
769:
768:
765:
763:
759:
753:
752:
746:
745:Panarthropoda
743:
742:
739:
738:
730:
729:
726:
724:
720:
714:
713:
710:
709:
706:
704:
700:
694:
693:
687:
684:
683:
677:
676:
673:
672:
664:
663:
660:
658:
654:
648:
647:
644:
643:
640:
638:
634:
628:
627:
621:
618:
617:
611:
608:
607:
603:
598:
593:
591:
589:
585:
584:
579:
578:Trace fossils
575:
571:
570:Burgess Shale
567:
560:
556:
555:
550:
546:
539:
538:Burgess Shale
535:
534:
529:
523:Fossil record
522:
520:
518:
513:
509:
501:
499:
496:
492:
488:
487:gonochoristic
483:
481:
478:
474:
470:
469:basiepidermal
466:
462:
457:
455:
451:
447:
442:
440:
437:
433:
429:
425:
421:
417:
412:
410:
401:
399:
397:
393:
388:
386:
382:
378:
374:
370:
365:
364:
359:
355:
351:
347:
343:
339:
335:
330:
328:
324:
320:
316:
312:
308:
304:
300:
296:
292:
288:
284:
280:
276:
272:
264:
263:
258:
253:
246:
243:
240:
239:
236:
233:
230:
227:
226:
223:
220:
218:Superphylum:
217:
216:
213:
210:
207:
206:
203:
200:
197:
194:
193:
190:
187:
184:
181:
180:
177:
174:
171:
168:
167:
164:
161:
158:
157:
154:
151:
148:
147:
144:
141:
138:
137:
132:
127:
123:
120:
119:
114:
110:
105:
98:
93:
88:
83:
78:
73:
68:
63:
58:
53:
48:
43:
36:
22:
19:
5050:
5021:
5013:
4935:Orthonectida
4930:Gastrotricha
4905:Nematomorpha
4894:
4880:Chaetognatha
4870:Hemichordate
4797:Pteridophyta
4666:Malawimonada
4540:Korarchaeota
4501:Thermotogota
4486:Synergistota
4461:Nitrospirota
4456:Nitrospinota
4401:Deinococcota
4334:Bacteroidota
4233:Potentially
4228:
4181:
4157:
4151:Gymnolaemata
4146:Stenolaemata
4135:Ectoproctans
4133:
4104:
4075:
4051:
4045:Pterobranchs
4032:
4008:
3984:
3960:
3936:
3930:within phyla
3928:Major groups
3798:
3785:Bryozoa s.l.
3776:Lophophorata
3764:
3740:
3718:
3710:
3673:
3662:Orthonectida
3637:
3584:
3577:
3566:
3485:
3478:
3407:
3377:
3365:Scalidophora
3314:
3302:Ambulacraria
3289:
3202:(see below↓)
3182:
3174:
3138:
3089:Opisthokonta
2949:
2927:
2916:
2896:
2889:
2862:
2858:
2849:
2841:
2804:
2800:
2790:
2765:
2761:
2738:
2703:
2699:
2693:
2685:
2663:(1): 37–46.
2660:
2656:
2650:
2613:
2609:
2603:
2595:
2562:
2558:
2552:
2544:
2527:11380/303453
2507:
2503:
2493:
2474:
2468:
2451:
2447:
2443:
2437:
2415:(1): 37–46.
2412:
2408:
2398:
2361:
2357:
2324:
2317:
2298:
2265:
2258:
2233:
2229:
2219:
2194:
2190:
2184:
2168:. Springer.
2164:
2157:
2141:. Springer.
2137:
2130:
2089:
2085:
2078:
2064:
2044:
2034:
2023:
1998:
1994:
1984:
1959:
1955:
1949:
1938:
1931:Priapuloidea
1890:
1886:
1876:
1843:
1839:
1804:
1799:Walcott 1911
1793:
1788:Walcott 1911
1771:
1755:Walcott 1911
1749:
1744:Walcott 1911
1731:Scolecofurca
1729:
1721:Ottoiomorpha
1707:
1699:Selkirkiidae
1691:
1690:Stem-group †
1689:
1681:Walcott 1912
1675:
1653:
1636:Ancalagonida
1629:Scalidophora
1628:
1627:Stem-group †
1626:
1545:Tubiluchidae
1431:
1429:
1421:
1412:
1299:Lamarck 1816
1293:
1292:
1273:
1272:
1248:Priapulopsis
1246:
1245:
1210:
1208:
1189:
1187:
1151:
1150:
1121:
1120:
1070:
1069:
1050:
1049:
1030:
1028:
1017:Tubiluchidae
996:
979:
953:
927:
925:
902:Ancalagonida
899:
883:
867:
806:
786:
756:
719:Nematomorpha
717:
697:
651:
632:
631:
620:Scalidophora
602:
581:
574:microfossils
564:
558:
552:
531:
511:
507:
505:
484:
458:
453:
443:
439:haemerythrin
413:
405:
389:
377:Scalidophora
363:Pambdelurion
361:
331:
326:
322:
290:
286:
278:
274:
270:
269:
260:
244:
235:Scalidophora
228:
208:(unranked):
195:
182:
169:
159:Subkingdom:
116:
18:
5142:iNaturalist
5075:Wikispecies
4990:Brachiopoda
4965:Cycliophora
4910:Onychophora
4885:Kinorhyncha
4807:Ginkgophyta
4802:Cycadophyta
4767:Chlorophyta
4757:Glaucophyta
4451:Myxococcota
4369:Chlorobiota
4364:Chlamydiota
4209:Tusk shells
4194:Cephalopods
4165:Polychaetes
4112:Turbellaria
4093:Crustaceans
4069:Secernentea
4059:Chromadorea
4040:Acorn worms
4010:Echinoderms
4002:Vertebrates
3944:Demosponges
3878:is disputed
3340:Protostomia
3228:is disputed
3155:ParaHoxozoa
2381:10037/30213
2001:: 113–130.
1763:Corynetidae
1498:Priapulidae
1434:Théel 1906
1195:Schram 1973
1191:Priapulites
1169:Priapulidae
1153:Halicryptus
1116:Maccabeidae
981:Kinorhyncha
933:Valkov 1983
758:Onychophora
653:Kinorhyncha
549:Microfossil
517:bilaterians
428:respiratory
396:meiobenthic
369:Kinorhyncha
360:-arthropod
291:penis worms
249:Théel, 1906
212:Protostomia
176:ParaHoxozoa
5258:Priapulida
5252:Categories
5095:Priapulida
5081:Priapulida
5051:Priapulida
5023:Parakaryon
4985:Entoprocta
4920:Arthropoda
4915:Tardigrada
4895:Priapulida
4890:Loricifera
4875:Echinoderm
4845:Ctenophora
4817:Gnetophyta
4772:Charophyta
4762:Rhodophyta
4734:Ascomycota
4729:Zygomycota
4671:Metamonada
4646:Euglenozoa
4631:Ciliophora
4339:Balneolota
4314:Aquificota
4189:Gastropods
4170:Clitellata
4077:Arthropods
4016:Sea lilies
3962:Cnidarians
3880:; see also
3810:Brachiozoa
3573:Syndermata
3532:Gnathifera
3230:; see also
3175:Trichoplax
3173:Placozoa (
3160:Planulozoa
2832:2381/38663
1893:(4): 8–13.
1820:References
1785:Miskoiidae
1667:Fieldiidae
1501:Gosse 1855
1432:Priapulida
1407:See also:
1072:Tubiluchus
1056:Morse 1981
997:Priapulida
808:Arthropoda
788:Tardigrada
633:Priapulida
432:phagocytic
385:polychaete
373:Loricifera
350:arthropods
271:Priapulida
245:Priapulida
35:Stem-group
24:Priapulida
4940:Dicyemida
4812:Pinophyta
4691:Telonemia
4626:Cryptista
4616:Breviatea
4601:Amoebozoa
4596:Alveolata
4577:Eukaryote
4329:Bacillota
4175:Sipuncula
4122:Monogenea
4117:Trematoda
4088:Myriapods
4053:Nematodes
3997:Tunicates
3992:Lancelets
3986:Chordates
3978:Myxozoans
3885:Nephrozoa
3874:phylogeny
3674:Salinella
3629:Rouphozoa
3470:Tactopoda
3399:Nematoida
3351:Ecdysozoa
3272:Bilateria
3259:Bilateria
3240:Benthozoa
3235:Eumetazoa
3224:phylogeny
3194:Bilateria
3084:Amoebozoa
3062:Alveolata
3050:Cryptista
3025:Eukaryota
2510:: 79–87.
2454:: 39–58.
2390:1432-234X
1929:(1911). "
1806:Louisella
1773:Corynetis
1741:Ottoiidae
1709:Selkirkia
1655:Ancalagon
1295:Priapulus
1123:Maccabeus
929:Markuelia
775:Tactopoda
686:Nematoida
610:Ecdysozoa
594:Phylogeny
495:flatworms
454:Priapulus
409:chitinous
354:nematodes
346:Ecdysozoa
338:Sipuncula
303:proboscis
285:' + Lat.
222:Ecdysozoa
202:Nephrozoa
189:Bilateria
163:Eumetazoa
149:Kingdom:
143:Eukaryota
5060:Wikidata
5000:Annelida
4995:Mollusca
4975:Phoronid
4970:Nemertea
4945:Rotifera
4925:Flatworm
4900:Nematoda
4865:Chordate
4855:Cnidaria
4850:Placozoa
4681:Rhizaria
4656:Haptista
4636:Cercozoa
4296:Bacteria
4199:Bivalves
4183:Molluscs
4159:Annelids
3518:Spiralia
3125:Animalia
3079:Amorphea
3057:Rhizaria
3045:Hacrobia
3035:Excavata
3020:Bacteria
2730:23103190
2642:19470151
2587:11175247
2579:18460094
2536:84539380
2114:18322464
1976:31342308
1962:: 1–12.
1868:39772232
1860:10881389
1783:Family †
1761:Family †
1739:Family †
1697:Family †
1665:Family †
1643:Family †
1127:Por 1973
699:Nematoda
588:Cambrian
473:ectoderm
424:vascular
420:hemocoel
392:Cambrian
342:Gephyrea
319:salinity
317:and low
262:See text
241:Phylum:
153:Animalia
139:Domain:
5199:1085175
5134:5963150
4980:Bryozoa
4676:Provora
4651:Jakobea
4641:Discoba
4587:Protist
4524:Archaea
4277:Extant
4204:Chitons
4127:Cestoda
4064:Enoplea
3938:Sponges
3711:Symbion
3654:Mesozoa
3094:Animals
3015:Archaea
2991:Extant
2867:Bibcode
2809:Bibcode
2770:Bibcode
2762:Geology
2708:Bibcode
2677:3226738
2633:2693540
2429:3226738
2238:Bibcode
2211:3227009
2122:4397099
2094:Bibcode
2003:Bibcode
1937:(ed.).
1924::
1803:Genus †
1795:Miskoia
1792:Genus †
1770:Genus †
1748:Genus †
1728:Genus †
1719:Order †
1706:Genus †
1677:Fieldia
1674:Genus †
1652:Genus †
1634:Order †
1597:Family
1543:Family
1496:Family
1447:Family
1430:Phylum
1216:Hu 2002
536:in the
465:ganglia
450:pharynx
402:Anatomy
387:worms.
381:scalids
334:Echiura
293:, is a
283:Priapus
279:priāpos
255:Orders
5235:101063
5222:230487
5219:uBio:
5212:272411
5173:155153
5147:151838
5108:392644
4840:Sponge
4832:Animal
4229:bolded
3072:Plants
3009:Domain
2993:animal
2904:
2850:Ottoia
2728:
2675:
2640:
2630:
2585:
2577:
2534:
2481:
2427:
2388:
2332:
2305:
2273:
2209:
2172:
2145:
2120:
2112:
2086:Nature
2052:
1974:
1933:". In
1918:
1866:
1858:
1751:Ottoia
1591:Order
1438:Order
1423:Ottoia
559:et al.
554:Ottoia
480:organs
416:coelom
398:size.
315:anoxia
295:phylum
5230:WoRMS
5186:33467
5155:IRMNG
5066:Q5184
4749:Plant
4701:Fungi
4621:CRuMs
3391:N+L+P
3099:Fungi
2996:phyla
2855:(PDF)
2673:JSTOR
2616:: 8.
2583:S2CID
2532:S2CID
2425:JSTOR
2207:JSTOR
2118:S2CID
1972:S2CID
1864:S2CID
477:sense
307:penis
299:worms
229:Clade
196:Clade
183:Clade
170:Clade
5181:NCBI
5168:ITIS
5129:GBIF
5121:1533
5103:BOLD
4787:Moss
4279:life
3872:The
3222:The
2902:ISBN
2726:PMID
2638:PMID
2575:PMID
2479:ISBN
2386:ISSN
2330:ISBN
2303:ISBN
2271:ISBN
2170:ISBN
2143:ISBN
2110:PMID
2050:ISBN
1856:PMID
561:2015
459:The
444:The
371:and
358:stem
352:and
336:and
287:-ul-
42:PreꞒ
5160:249
5116:EoL
5090:AFD
3729:M+K
3621:R+M
3558:M+S
3427:L+P
2875:doi
2827:hdl
2817:doi
2778:doi
2716:doi
2665:doi
2661:110
2628:PMC
2618:doi
2567:doi
2522:hdl
2512:doi
2456:doi
2452:129
2417:doi
2413:110
2376:hdl
2366:doi
2362:142
2246:doi
2234:253
2199:doi
2195:118
2102:doi
2090:452
2011:doi
1999:302
1964:doi
1960:222
1848:doi
426:or
5254::
5232::
5209::
5196::
5183::
5170::
5157::
5144::
5131::
5118::
5105::
5092::
5077::
5062::
2952:.
2948:.
2873:.
2863:58
2861:.
2857:.
2825:.
2815:.
2805:60
2803:.
2799:.
2776:.
2766:38
2764:.
2752:^
2724:.
2714:.
2704:22
2702:.
2698:.
2671:.
2659:.
2636:.
2626:.
2612:.
2608:.
2581:.
2573:.
2563:10
2561:.
2557:.
2530:.
2520:.
2508:70
2506:.
2502:.
2450:.
2423:.
2411:.
2407:.
2384:.
2374:.
2360:.
2356:.
2344:^
2285:^
2244:.
2232:.
2228:.
2205:.
2193:.
2116:.
2108:.
2100:.
2088:.
2009:.
1997:.
1993:.
1970:.
1958:.
1899:^
1891:40
1889:.
1885:.
1862:.
1854:.
1844:75
1842:.
1828:^
441:.
321:.
313:,
231::
198::
185::
172::
92:Pg
4589:"
4585:"
4549:"
4545:"
4542:"
4538:"
4535:"
4531:"
4392:"
4388:"
4270:e
4263:t
4256:v
4237:†
3713:)
3678:†
3676:)
3162:)
3158:(
3106:)
2984:e
2977:t
2970:v
2910:.
2883:.
2877::
2869::
2852:"
2835:.
2829::
2819::
2811::
2784:.
2780::
2772::
2746:.
2732:.
2718::
2710::
2696:"
2679:.
2667::
2644:.
2620::
2614:6
2606:"
2589:.
2569::
2555:"
2538:.
2524::
2514::
2487:.
2462:.
2458::
2431:.
2419::
2392:.
2378::
2368::
2338:.
2311:.
2279:.
2252:.
2248::
2240::
2213:.
2201::
2178:.
2151:.
2124:.
2104::
2096::
2072:.
2058:.
2017:.
2013::
2005::
1978:.
1966::
1870:.
1850::
1209:†
1188:†
1029:†
954:†
926:†
900:†
884:†
281:'
273:(
97:N
87:K
82:J
77:T
72:P
67:C
62:D
57:S
52:O
47:Ꞓ
33:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
