614:
598:
630:
1532:
156:
523:. The roots of the body sclerites were significantly narrower than the sclerites, but the spines had roots about as wide as their bases; both types of root were made of fairly soft tissue. They bore protrusive, presumably structural, ribs on their upper and (seemingly) lower surfaces. The sclerites and spines were not mineralized, but made of a tough organic (carbon-based) biopolymer. Butterfield (1990) examined some sclerites under both
508:, and formed a single row. Larger specimens (>~15 mm) bear two rows of ribbed spines running from front to rear, one along each side of the top surface, and projecting out and slightly upward, with a slight upward curve near the tips. Although the spines in the middle of each row are usually the longest, up to 5 centimetres (2 in) long, a few specimens have rather short middle spines that represent part-grown replacements.
1497:, it possessed spines and regions of sclerites (although it is only known from disarticulated remains), but the sclerites bear a higher density of ribs, and there are two distinct thicknesses of rib (i.e. larger and smaller). At a microscopic level, the sclerites do not differ from Burgess Shale or Mount Cap sclerites, but the Chinese material seems to have developed spines from an early age, distinguishing it from the
845:
652:
134:
1501:. The knob-bearing sclerites from all three localities seem to belong to a different species, and a further species is represented in the Xiaoshiba deposits. What is surprising is the limited variety exhibited between species: all have a fundamentally equivalent scleritome, displaying a notable degree of morphological stasis for some 15 Ma.
500:; these lay flat against the body, overlapped so that the rear of one covered the front of the one behind, and formed five main regions—the top; the upper part of the sides; the lower part of the sides; the front; and the bottom. Most of the sclerites were shaped like oval leaves, but the ventro-lateral ones, nearest the sea-floor, were
421:
animal's front in an average specimen about 2.5 centimetres (0.98 in) long, there was a feeding apparatus that consisted of two (or in rare large specimens three) rows of backward-pointing conical teeth. The feeding apparatus was tough enough to be frequently preserved, but unmineralized and fairly flexible.
411:. It reached 5 centimetres (2 in) in length. Estimating their height is difficult because specimens were compressed after death; a typical specimen may have been 1 centimetre (0.39 in) high excluding the spines on their backs. The ratio of width to length does not appear to change as the animals grew.
576:
scleritome comprises eight rows of sclerites, arranged in bundles. Sclerites are periodically shed and replaced during growth, with the number of sclerites in a given bundle increasing as the animal ages to produce a thicker scleritome. Once specimens reach a certain size, spines are added to the
420:
flat underside was soft and unarmored; most of the surface was occupied by a single slug-like foot. Little is known of the internal anatomy, although the gut apparently ran straight and all the way from the front to the rear. At the front end of the gut, about 5 millimetres (0 in) from the
511:
Each sclerite was rooted separately in the body; the roots of body sclerites are 40% of the external length or a little less, while the roots of the spines are a little over 25% of the external length; all were rooted in pockets in the skin, rather like the
332:
and middle
Cambrian fossil deposits across the globe. The living animal would have measured up to 5 centimetres (2 in) when fully grown, although a range of juvenile specimens are known, the smallest being 2 millimetres (0.08 in) long.
721:
recognised today were beginning to diverge. Consequently, many lineages (that would later become extinct) appear intermediate to two or more modern groups, or lack features common to all modern members of a group, and hence fall into the
2940:
Yuanlong, Z.; Maoyan, Z.H.U.; Babcock, L.E.; Jinliang, Y.; Parsley, R.L.; Jin, P.; Xinglian, Y.; Yue, W. (2005). "Kaili Biota: A Taphonomic Window on
Diversification of Metazoans from the Basal Middle Cambrian: Guizhou, China".
917:
showed traces of a small shell, possibly a vestige left over from an earlier stage in the animal's evolution, and noted that one group of modern polychaetes also has what may be a vestigial shell. However, they maintained that
862:
feeding apparatus, instead of being mounted in the middle of its "head", was just as likely to be mounted in two parts on the sides of the "head", an arrangement that is common in polychaetes. He went so far as to classify
1356:
was originally described by G. F. Matthew in 1899, from an isolated spine that had been found earlier in the
Ogyopsis Shale, and classified as "Orthotheca corrugata". Further specimens were found by American
1578:
Kimmig, Julien; Couto, Helena; Leibach, Wade W.; Lieberman, Bruce S. (25 May 2019). "Soft-bodied fossils from the upper
Valongo Formation (Middle Ordovician: Dapingian-Darriwilian) of northern Portugal".
1515:
Younger spines of possible wiwaxiid origin have been observed from the
Valongo Formation (Middle Ordovician: Dapingian-Darriwilian) of northern Portugal and have been reported, if not described, from the
1341:
A 2012 study redescribing the mouthparts found a number of similarities with the molluscan radula, and overthrew some of the better arguments for an annelid affinity, seemingly demonstrating that
3122:
Ivantsov, A.Yu.; Zhuravlev, A.Yu.; Legutaa, A.V.; Krassilova, V.A.; Melnikovaa, L.M.; Ushatinskaya, G.T. (2005). "Palaeoecology of the early
Cambrian Sinsk biota from the Siberian Platform".
342:
affinity has been a matter of debate: Researchers were long split between two possibilities. On the one hand, its rows of scales looked superficially similar to certain scale worms (
3510:
937:, as the sclerites are divided into similar groups, although those of halkieriids were much smaller and more numerous; they also said that in 1994 Butterfield had found
1327:
as a polychaete, he thought it was a serious objection given the lack of other clearly polychaete features. In his opinion there were no strong grounds for classifying
3500:
3393:
757:
distantly related to the molluscs; a crown-group polychaete; a stem-group annelid; a problematic bilaterian; a stem- or possibly primitive crown-group mollusc.
2554:
Conway Morris, S. & Peel, J.S. (1995). "Articulated
Halkieriids from the Lower Cambrian of north Greenland and their role in early protostome evolution".
834:" and in overall appearance. Some modern annelids also develop on each side rows of longer bristles, which both Walcott and Butterfield considered similar to
806:'s lectures, agreed that the sclerites were not like elytra, which are relatively fleshy and soft. However, since the sclerites were solid, he concluded that
3490:
2823:
Southgate, P.N. & Shergold, J.H. (1991). "Application of sequence stratigraphic concepts to Middle
Cambrian phosphogenesis, Georgina Basin, Australia".
2659:
Scheltema, A. H.; Ivanov, D. L. (2002). "An aplacophoran postlarva with iterated dorsal groups of spicules and skeletal similarities to
Paleozoic fossils".
1426:
was not a polychaete. All the known specimens came from in and around the
Burgess Shale until 1991, when fragmentary fossils were reported from Australia's
2598:
2388:
3231:
1338:
as an early polychaete and adding that, while bristles are a feature of several groups, they appear as a covering over the back only in polychaetes.
1323:
body do not correspond to any reasonable pattern of segmentation; while Eibye-Jacobsen did not think that this alone would prevent classification of
3367:
3281:
478:
434:
2725:
Matthew, G.F. (1899). "Studies on Cambrian Faunas, No. 3. — Upper Cambrian Fauna, Mount Stephen, British Columbia. — The Trilobites and Worms".
1410:
revisited the Burgess Shale and found so many fossils that it took years to analyze them all. Four hundred and sixty-four complete specimens of
535:
leaves. The sclerites bear an internal fabric of longitudinal chambers, which suggest that they were secreted from their bases in the manner of
3485:
3475:
1231:, animals whose modern forms have bivalve shells, but differ from molluscs in having muscular stalks and a distinctive feeding apparatus, the
3058:
2756:
830:
form leaf-like scales that cover the back like roof tiles—in composition, in detailed structure, in how they were attached to the body via "
1287:
and the larvae of certain solenogaster molluscs, which bear iterated calcareous sclerites arranged into three symmetrical lateral zones.
3515:
3470:
1331:
as a proto-annelid or a proto-mollusc, although he thought the objections against classification as a proto-annelid were the stronger.
3480:
433:
3495:
753:("scales") of annelids. More recently the debate has been intense, and proposed classifications include: a member of an extinct
531:
and concluded that they were not hollow, and that the bases split and spread to form the blades, a pattern that is also seen in
3465:
1545:
1508:, suggesting that the spines were more recalcitrant (or more commonly collected); however, in well-preserved sites such as the
3157:
Butterfield, N.J.; Harvey, T.H.P. (2011). "Small carbonaceous fossils (SCFs): A new measure of early Paleozoic paleobiology".
3460:
2495:
1433:
Articulated specimens are known from Cambrian Stage 3 of Xiaoshiba, China; fragmentary specimens have also been found in the
3077:
Butterfield, N.J. (1994). "Burgess Shale-type fossils from a Lower Cambrian shallow-shelf sequence in northwestern Canada".
1316:
closest relative was the annelids. He also pointed out that the very different numbers of sclerites in the various zones of
2772:
Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale".
886:
is no barrier to this, as some modern polychaetes also show no segmentation except during development. He later noted that
734:
can be placed within a modern crown group and, if it cannot, in which group's stem it falls. When Walcott first described
528:
2638:
2449:
Conway Morris, S. & Peel, J.S. (June 1990). "Articulated halkieriids from the Lower Cambrian of north Greenland".
2428:
901:
as an ancestor or "aunt" of the polychaetes, and said Butterfield had informed them that the microscopic structure of
485:
407:; viewed from the top the body was elliptical with no distinct head or tail, and from the front or rear it was almost
1512:, spine and sclerite abundance is comparable, in disarticulated instances, to the proportions on complete fossils.
890:
lack some polychaete features which he would expect to be easily preserved in fossils, and therefore a stem-group
814:
that had been proposed in order to unite organisms with hollow sclerites, and could not be closely related to the
771:
sclerites were different in construction from annelids' elytra. He was more impressed by the similarities between
2362:
1478:
1361:
2111:
155:
2599:"Original Molluscan Radula: Comparisons Among Aplacophora, Polyplacophora, Gastropoda, and the Cambrian Fossil
1217:
were a "sister" group to the molluscs, in other words descendants of a fairly closely related common ancestor.
3437:
324:
of soft-bodied animals that were covered in carbonaceous scales and spines that protected it from predators.
1302:. Eibye-Jacobsen regarded bristles as a feature shared by molluscs, annelids and brachiopods. Hence even if
785:, and assigned the animal to a new taxon Molluscata, which he proposed should also contain the molluscs and
404:
3293:
3505:
3320:
2097:
1505:
883:
3419:
3031:
1430:. In 2004 additional finds which may represent two different species were reported from the same area.
1334:
Butterfield returned to the debate in 2006, repeating the arguments he presented in 1990 for regarding
3243:
3166:
3131:
3088:
2950:
2906:
2859:
2781:
2699:
2563:
2460:
2268:
2155:
2089:
1957:
1879:
1803:
1790:
Morris, Simon Conway; Selden, Paul A.; Gunther, Glade; Jamison, Paul G.; Robison, Richard A. (2015).
1714:
1654:
1588:
1407:
818:, which have hollow sclerites. Instead he thought that they were very similar in several ways to the
2102:
2991:"Burgess Shale-type microfossils from the middle Cambrian Kaili Formation, Guizhou Province, China"
1550:
1537:
1450:
1419:
761:
559:
613:
350:. More recently, evidence for a molluscan affinity has been accumulating, based on new details of
3301:
3259:
3232:"The Fezouata fossils of Morocco; an extraordinary record of marine life in the Early Ordovician"
3104:
3012:
2966:
2922:
2875:
2805:
2797:
2630:
2579:
2525:
2476:
2420:
2335:
2286:
2179:
2171:
2115:
1975:
1895:
1829:
1612:
1517:
524:
328:
fossils—mainly isolated scales, but sometimes complete, articulated fossils—are known from early
150:
2080:
Porter, S.M. (May 2004). "Halkieriids in Middle Cambrian Phosphatic Limestones from Australia".
693:
appears to have been solitary rather than gregarious. The feeding apparatus may have acted as a
346:); conversely, its mouthparts and general morphology suggested a relationship to the shell-less
667:
apparently moved by contractions of a slug-like foot on its underside. In one specimen a small
597:
3424:
3406:
3398:
3306:
3054:
2752:
2744:
2622:
2517:
2412:
2327:
2218:
2039:
1821:
1740:
1680:
1604:
1470:
1466:
1434:
1049:
803:
549:
30:
3411:
2057:
659:
from the Burgess Shale, viewed side-on; mouthparts are visible to anterior. From Smith (2013)
3251:
3212:
3174:
3139:
3096:
3079:
3002:
2958:
2914:
2867:
2789:
2707:
2668:
2614:
2571:
2507:
2468:
2451:
2404:
2317:
2276:
2226:
2210:
2163:
2107:
2029:
2021:
1965:
1887:
1811:
1730:
1722:
1670:
1662:
1596:
682:
did not burrow or even plough much into the sea-floor as they moved. Two other specimens of
629:
362:
38:
1422:, then a member of Whittington's team, published a detailed description and concluded that
2305:
1490:
1462:
1458:
1442:
1380:
868:
678:, appears to be attached to one of the ventro-lateral sclerites. This suggests that adult
536:
34:
2897:
material from the Tsinghsutung Formation (Cambrian Series 2) of Eastern Guizhou, China".
1275:
molluscs, and that the sclerites of the two groups are very similar. They concluded that
3247:
3170:
3135:
3092:
2954:
2910:
2863:
2785:
2703:
2567:
2464:
2272:
2159:
2093:
1961:
1883:
1807:
1718:
1658:
1592:
2962:
2842:
Zhao, F.C.; Smith, M.R.; Yin, Z.-J.; Zeng, H.; Hu, S.-X; Li, G.-X.; Zhu, M.-Y. (2015).
2672:
2231:
2198:
2034:
2001:
1735:
1702:
1675:
1638:
1493:. The Chinese material was originally considered to represent a separate species; like
1486:
1446:
1427:
1358:
1224:
187:
2989:
Harvey, T.; Ortega-Hernández, J.; Lin, J.-P.; Yuanlong, Z.; Butterfield, N.J. (2011).
2843:
2199:"Colour in Burgess Shale animals and the effect of light on evolution in the Cambrian"
3454:
3358:
3263:
3192:
Smith, Martin R.; Hughes, Gareth M.G.; Vargas, MarĂa C.; de la Parra, Felipe (2015).
2970:
2926:
2879:
2119:
1616:
1509:
1454:
1415:
1365:
1244:
1221:
1099:
831:
702:
513:
389:
118:
80:
3016:
2809:
2634:
2529:
2424:
2339:
2290:
2183:
1979:
1833:
3108:
3053:. Toronto, Ontario, Canada: The Burgess Shale Consortium (published 31 July 2009).
2480:
1703:"New reconstruction of the Wiwaxia scleritome, with data from Chengjiang juveniles"
1555:
1396:
905:
s sclerites was identical to that of the bristles of two Burgess Shale polychaetes
897:
Conway Morris and Peel (1995) largely accepted Butterfield's arguments and treated
872:
1309:
sclerites closely resembled bristles, which he doubted, this would not prove that
477:
392:; other species are known only from fragmentary material or limited sample sizes.
3143:
1870:(Matthew) from the Burgess Shale and Ogygopsis Shale, British Columbia, Canada".
3380:
3352:
2138:
Butterfield, N.J. (1990). "A reassessment of the enigmatic Burgess Shale fossil
1369:
1272:
1155:
851:
from the Burgess Shale. Mouthparts are visible in enlargement. From Smith (2013)
706:
408:
358:
55:
2793:
1445:, in the Middle Cambrian beds of the Tyrovice Member, Buchava Formation of the
2918:
2871:
2711:
2167:
1600:
1527:
1400:
1384:
1295:
1232:
1228:
1214:
1105:
989:
942:
934:
844:
815:
739:
723:
668:
651:
555:
369:
133:
122:
100:
65:
3343:
2222:
1825:
2075:
2073:
2071:
1283:
that includes molluscs. Scheltema has also highlighted similarities between
1138:
802:
Nick Butterfield, then a postgraduate paleontologist at Harvard inspired by
791:
684:
673:
167:
105:
49:
2626:
2575:
2521:
2512:
2416:
2365:(1911). "Middle Cambrian annelids. Cambrian geology and paleontology, II".
2331:
2322:
2214:
2043:
2025:
1891:
1744:
1684:
1608:
3007:
2990:
3337:
3193:
2253:"Ontogeny, morphology and taxonomy of the soft-bodied Cambrian 'mollusc'
1942:"Ontogeny, morphology and taxonomy of the soft-bodied Cambrian 'mollusc'
1792:"New records of Burgess Shale-type taxa from the middle Cambrian of Utah"
1504:
Isolated spines are more common than sclerites in localities with a poor
1033:
966:
786:
746:
698:
544:
501:
497:
496:
The animal was covered in eight rows of small ribbed armor plates called
347:
329:
197:
95:
90:
75:
70:
60:
3255:
3230:
van Roy, Peter; Briggs, Derek E.G.; Gaines, Robert R. (September 2015).
2801:
1816:
1791:
764:
agreed that there were similarities to polychaetes, but considered that
3432:
3372:
2618:
2408:
2281:
2252:
2175:
1970:
1941:
1899:
1438:
1388:
1299:
891:
779:
742:
532:
343:
110:
85:
42:
3385:
3216:
3045:. In Smith, Martin R.; O'Brien, Lorna J.; Caron, Jean-Bernard (eds.).
1726:
1666:
3178:
3100:
2583:
2472:
1374:
1268:
926:
819:
782:
754:
750:
718:
517:
505:
177:
3314:
1477:
Biota of Siberia, Russia. Isolated sclerites are also common in the
1771:
from Early-Middle Cambrian Kaili Formation in Taijiang, Guizhou".
1474:
1280:
1239:
843:
827:
823:
811:
727:
663:
The long dorsal spines may have been a defense against predators.
650:
321:
3051:
International Conference on the Cambrian Explosion (Walcott 2009)
1418:, where they comprise 0.88% of the community. Eventually in 1985
789:. When he later described the first fairly complete specimens of
694:
586:
520:
3318:
1637:
Yang, J.; Smith, M.R.; Lan, T.; Hou, J.B.; Zhang, X.G. (2014).
3198:
from the temperate palaeolatitudes of Colombia, South America"
826:) that project from the bodies of modern annelids and in some
357:
mouthparts, scales, and growth history. The name derives from
1220:
The halkieriids which Conway Morris had found in Greenland's
933:
was fairly closely related to and in fact descended from the
3050:
2496:"Exceptional Fossil Preservation and the Cambrian Explosion"
1364:
in 1911 as a result of one of his field trips to the nearby
894:, in other words an evolutionary "aunt" of modern annelids.
388:, which is known from hundreds of complete specimens in the
2112:
10.1666/0022-3360(2004)078<0574:HIMCPL>2.0.CO;2
1872:
Philosophical Transactions of the Royal Society of London B
941:
sclerites that were clearly hollow. They presented a large
639:
individual. Each checkered square has an area of 1 mm.
623:
individual. Each checkered square has an area of 1 mm.
607:
individual. Each checkered square has an area of 1 mm.
3040:
from the Cambrian of the Barrandian Area (Czech Republic)"
1441:, China, and in China's lowermost Miaolingian beds of the
1290:
Danish zoologist Danny Eibye-Jacobsen argued in 2004 that
2893:
Sun, H.J.; Zhao, Y.L.; Peng, J.; Yang, Y.N. (2014). "New
913:. Conway Morris and Peel also wrote that one specimen of
2306:"The Cambrian Fossil Record and the Origin of the Phyla"
1866:
Conway Morris, S. (1985). "The Middle Cambrian metazoan
1485:
had a truly cosmopolitan distribution, occurring at all
2549:
2547:
2545:
2203:
Proceedings of the Royal Society B: Biological Sciences
589:, but in fact represents a single, folded, individual.
1696:
1694:
585:. One juvenile specimen was originally interpreted as
1643:
from the Cambrian stage 3 Xiaoshiba lagerstätte"
1294:
lacks any characters that would firmly place it as a
810:
could not be a member of the "Coeloscleritophora", a
1701:
Zhang, Zhifei; Smith, Martin R.; Shu, Degan (2015).
3327:
2597:Scheltema, A.H.; Kerth, K.; Kuzirian, A.M. (2003).
1573:
1571:
3072:
3070:
2382:
2380:
2133:
2131:
2129:
2010:: Implications for the ancestral molluscan radula"
1861:
1859:
1857:
1855:
1853:
1851:
1849:
1847:
1845:
1843:
795:, he suggested that these were closely related to
3124:Palaeogeography, Palaeoclimatology, Palaeoecology
2556:Philosophical Transactions of the Royal Society B
2142:(Matthew) and its relationship to the polychaete
925:feeding apparatus was much more like a molluscan
3292:. Virtual Museum of Canada. 2011. Archived from
1632:
1630:
1628:
1626:
2751:. London: Hutchinson Radius. pp. 77, 189.
2727:Philosophical Transactions of the Royal Society
2393:: fossil lophotrochozoans in the Burgess Shale"
2686:Eibye-Jacobsen, D. (2004). "A reevaluation of
2357:
2355:
1481:record. Taken together, these finds show that
689:have been found attached to dorsal sclerites.
2984:
2982:
2980:
2246:
2244:
2242:
709:to gather food particles from the sea-floor.
376:as well as several similar Cambrian animals.
8:
2825:Journal of Australian Geology and Geophysics
1935:
1933:
1931:
1929:
3511:Paleozoic life of the Northwest Territories
3030:Kraft, Petr; Fatka, Oldrich (August 2009).
2690:and the polychaetes of the Burgess Shale".
1995:
1993:
1991:
1989:
1927:
1925:
1923:
1921:
1919:
1917:
1915:
1913:
1911:
1909:
3315:
1762:
1760:
1758:
1756:
1754:
1207:Cladogram: Conway Morris & Peel (1995)
841:dorsal spines. including the halkieriids.
476:
145:from the Burgess Shale. From Smith (2014)
132:
20:
3006:
2848:from the Cambrian Chengjiang lagerstätte"
2511:
2321:
2280:
2230:
2101:
2033:
2002:"Mouthparts of the Burgess Shale fossils
1969:
1815:
1734:
1674:
1267:feeding apparatus is very similar to the
384:This article concentrates on the species
1767:Zhao, Y.L.; Qian, Y.; Li, X.S. (1994). "
577:scleritome; this size is ~15 mm in
3501:Taxa named by Charles Doolittle Walcott
2943:Acta Geologica Sinica - English Edition
1567:
3194:"Sclerites and possible mouthparts of
1453:(Mackenzie Mountains, Canada), in the
1383:; he classified it as a member of the
619:Computer reconstruction of adolescent
562:, although questioned in later study.
2367:Smithsonian Miscellaneous Collections
1256:Marine biologist Amélie H. Scheltema
1248:, was a "great aunt" of annelids and
248:
7:
3438:E749AE89-056D-4391-91FD-FE4418A8FAAC
705:that covered the sea-floor, or as a
603:Computer reconstruction of juvenile
3491:Cambrian Series 2 first appearances
2310:Integrative and Comparative Biology
1130:
1026:
1019:
1012:
1005:
981:
959:
952:
2963:10.1111/j.1755-6724.2005.tb00928.x
2673:10.1111/j.1744-7410.2002.tb00124.x
2014:Proceedings of the Royal Society B
730:. Debate is ongoing as to whether
635:Computer reconstruction of mature
14:
3236:Journal of the Geological Society
717:During the Cambrian, most of the
1530:
1437:, Cambrian Series 2 deposits in
1406:In 1966 and 1967, a team led by
855:Butterfield also contended that
628:
612:
596:
432:
154:
1546:Paleobiota of the Burgess Shale
504:-shaped, rather like flattened
491:sclerite zones, seen from front
554:, its sclerites may have been
1:
3486:Fossil taxa described in 1911
3476:Prehistoric protostome genera
2995:Acta Palaeontologica Polonica
1473:, and in the Middle Botomian
1395:, citing similarities to the
581:but substantially smaller in
529:scanning electron microscopes
274:Zhang, Smith & Shu, 2015
3290:Burgess Shale Fossil Gallery
3144:10.1016/j.palaeo.2004.01.022
2197:Parker, A. R. (1998-06-07).
141:Fossil showing underside of
1773:Acta Palaeontologica Sinica
1414:are known from the Greater
282:Zhao, Qian & Lee, 1994
3532:
3516:Cambrian genus extinctions
3471:Prehistoric marine animals
2794:10.2110/palo.2003.P05-070R
2494:Butterfield, N.J. (2003).
2387:Butterfield, N.J. (2006).
1271:of some modern shell-less
1252:was an "aunt" of annelids.
3481:Enigmatic protostome taxa
2919:10.1017/S0016756813000216
2872:10.1017/S0016756814000648
2712:10.1080/00241160410002027
2389:"Hooking some stem-group
2251:Smith, Martin R. (2014).
2168:10.1017/S0094837300010009
1601:10.1007/s00114-019-1623-z
1479:small carbonaceous fossil
1362:Charles Doolittle Walcott
1227:were a "sister" group to
1153:
1135:
1128:
1096:
1072:
1046:
1031:
1024:
1017:
1010:
1003:
986:
979:
964:
957:
719:main groupings of animals
247:
242:
151:Scientific classification
149:
140:
131:
23:
16:Genus of Cambrian animals
3302:"Orthrozanclus reburrus"
1449:, in the Lower Cambrian
929:. They also argued that
867:as a member of a modern
778:feeding apparatus and a
3496:Miaolingian extinctions
2082:Journal of Paleontology
2064:. Royal Ontario Museum.
1796:Journal of Paleontology
1391:worms in its own genus
1377: million years ago
875:, and pointed out that
405:bilaterally symmetrical
254:(Matthew, 1899) (type)
3466:Cambrian invertebrates
2576:10.1098/rstb.1995.0029
2215:10.1098/rspb.1998.0385
2026:10.1098/rspb.2012.1577
1892:10.1098/rstb.1985.0005
1506:preservation potential
1345:was indeed a mollusc.
852:
738:, he regarded it as a
660:
3461:Burgess Shale fossils
3420:Paleobiology Database
3008:10.4202/app.2011.0028
2607:Journal of Morphology
1581:The Science of Nature
847:
654:
2661:Invertebrate Biology
2513:10.1093/icb/43.1.166
2323:10.1093/icb/43.1.157
2000:Smith, M.R. (2012).
1940:Smith, M.R. (2014).
1408:Harry B. Whittington
945:according to which:
3310:(blog). 2007-03-02.
3256:10.1144/jgs2015-017
3248:2015JGSoc.172..541V
3171:2012Geo....40...71B
3136:2005PPP...220...69I
3093:1994Natur.369..477B
2955:2005AcGlS..79..751Z
2911:2014GeoM..151..339S
2899:Geological Magazine
2864:2015GeoM..152..378Z
2852:Geological Magazine
2786:2006Palai..21..451C
2704:2004Letha..37..317E
2568:1995RSPTB.347..305C
2465:1990Natur.345..802M
2304:Budd, G.E. (2003).
2273:2014Palgy..57..215S
2160:1990Pbio...16..287B
2094:2004JPal...78..574P
2058:"Wiwaxia corrugata"
2020:(1745): 4287–4295.
1962:2014Palgy..57..215S
1884:1985RSPTB.307..507M
1817:10.1017/jpa.2015.26
1808:2015JPal...89..411C
1719:2015NatSR...514810Z
1659:2014NatSR...4E4643Y
1593:2019SciNa.106...27K
1551:Coeloscleritophoran
1538:Paleontology portal
1451:Mount Cap formation
1420:Simon Conway Morris
1260:(2003) argued that
1238:Another halkieriid
762:Simon Conway Morris
701:off the top of the
560:diffraction grating
558:due to evidence of
368:The proposed clade
117:Possible record of
2619:10.1002/jmor.10121
2500:Integr. Comp. Biol
2409:10.1002/bies.20507
2282:10.1111/pala.12063
1971:10.1111/pala.12063
1707:Scientific Reports
1647:Scientific Reports
1379:) in the Canadian
1279:was a member of a
853:
749:as similar to the
661:
3448:
3447:
3407:Open Tree of Life
3321:Taxon identifiers
3284:Wiwaxia corrugata
3217:10.1111/let.12154
3087:(6480): 477–479.
3060:978-0-9812885-1-2
2844:"First report of
2758:978-0-09-174271-3
2601:Wiwaxia corrugata
2562:(1321): 305–358.
2459:(6278): 802–805.
2403:(12): 1161–1166.
2209:(1400): 967–972.
2140:Wiwaxia corrugata
1878:(1134): 507–582.
1868:Wiwaxia corrugata
1727:10.1038/srep14810
1667:10.1038/srep04643
1393:Wiwaxia corrugata
1202:
1201:
1193:
1192:
1184:
1183:
1175:
1174:
1166:
1165:
1117:
1116:
1085:
1084:
1061:
1060:
849:Wiwaxia corrugata
804:Stephen Jay Gould
657:Wiwaxia corrugata
637:Wiwaxia corrugata
621:Wiwaxia corrugata
605:Wiwaxia corrugata
386:Wiwaxia corrugata
313:
312:
307:
295:
283:
275:
267:
255:
238:
219:
143:Wiwaxia corrugata
126:
3523:
3441:
3440:
3428:
3427:
3415:
3414:
3402:
3401:
3389:
3388:
3376:
3375:
3363:
3362:
3361:
3348:
3347:
3346:
3316:
3311:
3297:
3268:
3267:
3227:
3221:
3220:
3202:
3189:
3183:
3182:
3179:10.1130/G32580.1
3154:
3148:
3147:
3119:
3113:
3112:
3101:10.1038/369477a0
3074:
3065:
3064:
3044:
3027:
3021:
3020:
3010:
2986:
2975:
2974:
2937:
2931:
2930:
2890:
2884:
2883:
2839:
2833:
2832:
2820:
2814:
2813:
2769:
2763:
2762:
2741:
2735:
2734:
2722:
2716:
2715:
2683:
2677:
2676:
2656:
2650:
2649:
2647:
2646:
2637:. Archived from
2594:
2588:
2587:
2551:
2540:
2539:
2537:
2536:
2515:
2491:
2485:
2484:
2473:10.1038/345802a0
2446:
2440:
2439:
2437:
2436:
2427:. Archived from
2384:
2375:
2374:
2359:
2350:
2349:
2347:
2346:
2325:
2301:
2295:
2294:
2284:
2248:
2237:
2236:
2234:
2194:
2188:
2187:
2135:
2124:
2123:
2105:
2077:
2066:
2065:
2054:
2048:
2047:
2037:
1997:
1984:
1983:
1973:
1937:
1904:
1903:
1863:
1838:
1837:
1819:
1787:
1781:
1780:
1764:
1749:
1748:
1738:
1698:
1689:
1688:
1678:
1634:
1621:
1620:
1575:
1540:
1535:
1534:
1533:
1491:palaeocontinents
1378:
1322:
1315:
1308:
1266:
1131:
1027:
1020:
1013:
1006:
982:
960:
953:
924:
882:lack of obvious
881:
861:
840:
777:
770:
632:
616:
600:
575:
480:
472:
471:
469:
462:
457:
452:
447:
442:
436:
419:
363:British Columbia
356:
341:
301:
289:
281:
279:W. taijiangensis
273:
261:
253:
236:
229:
217:
212:
201:
159:
158:
136:
116:
115:
52:
29:Temporal range:
21:
3531:
3530:
3526:
3525:
3524:
3522:
3521:
3520:
3451:
3450:
3449:
3444:
3436:
3431:
3423:
3418:
3410:
3405:
3397:
3392:
3384:
3379:
3371:
3366:
3357:
3356:
3351:
3342:
3341:
3336:
3323:
3300:
3280:
3277:
3272:
3271:
3229:
3228:
3224:
3200:
3191:
3190:
3186:
3156:
3155:
3151:
3121:
3120:
3116:
3076:
3075:
3068:
3061:
3047:Abstract Volume
3042:
3029:
3028:
3024:
2988:
2987:
2978:
2939:
2938:
2934:
2892:
2891:
2887:
2841:
2840:
2836:
2822:
2821:
2817:
2771:
2770:
2766:
2759:
2743:
2742:
2738:
2724:
2723:
2719:
2685:
2684:
2680:
2658:
2657:
2653:
2644:
2642:
2596:
2595:
2591:
2553:
2552:
2543:
2534:
2532:
2493:
2492:
2488:
2448:
2447:
2443:
2434:
2432:
2386:
2385:
2378:
2361:
2360:
2353:
2344:
2342:
2303:
2302:
2298:
2250:
2249:
2240:
2196:
2195:
2191:
2144:Canadia spinosa
2137:
2136:
2127:
2103:10.1.1.573.6134
2079:
2078:
2069:
2056:
2055:
2051:
1999:
1998:
1987:
1939:
1938:
1907:
1865:
1864:
1841:
1789:
1788:
1784:
1766:
1765:
1752:
1700:
1699:
1692:
1636:
1635:
1624:
1577:
1576:
1569:
1564:
1536:
1531:
1529:
1526:
1487:palaeolatitudes
1463:South Australia
1459:Kangaroo Island
1443:Kaili Formation
1381:Rocky Mountains
1373:
1351:
1320:
1313:
1306:
1264:
1210:
1209:
1208:
1205:
1204:
1203:
1194:
1185:
1176:
1167:
1118:
1103:
1086:
1062:
922:
879:
859:
838:
775:
768:
715:
649:
644:
643:
642:
641:
640:
633:
625:
624:
617:
609:
608:
601:
583:W. taijengensis
573:
568:
537:Lophotrochozoan
494:
493:
492:
487:
482:
481:
474:
473:
470: = Frontal
467:
466:
465:
463:
460:
458:
455:
453:
450:
448:
445:
443:
440:
437:
427:
417:
398:
382:
354:
339:
299:W. douposiensis
235:
227:
216:
210:
199:
153:
127:
114:
113:
108:
103:
98:
93:
88:
83:
78:
73:
68:
63:
58:
47:
46:
35:Middle Cambrian
27:
17:
12:
11:
5:
3529:
3527:
3519:
3518:
3513:
3508:
3503:
3498:
3493:
3488:
3483:
3478:
3473:
3468:
3463:
3453:
3452:
3446:
3445:
3443:
3442:
3429:
3416:
3403:
3390:
3377:
3364:
3349:
3333:
3331:
3325:
3324:
3319:
3313:
3312:
3298:
3296:on 2020-11-12.
3276:
3275:External links
3273:
3270:
3269:
3242:(5): 541–549.
3222:
3211:(3): 393–397.
3184:
3149:
3130:(1–2): 69–88.
3114:
3066:
3059:
3022:
3001:(2): 423–436.
2976:
2949:(6): 751–765.
2932:
2905:(2): 339–348.
2885:
2858:(2): 378–382.
2834:
2815:
2764:
2757:
2749:Wonderful Life
2736:
2717:
2698:(3): 317–335.
2678:
2651:
2613:(2): 219–245.
2589:
2541:
2506:(1): 166–177.
2486:
2441:
2376:
2351:
2316:(1): 157–165.
2296:
2267:(1): 215–229.
2238:
2189:
2154:(3): 287–303.
2125:
2088:(3): 574–590.
2067:
2049:
2004:Odontogriphus
1985:
1956:(1): 215–229.
1905:
1839:
1802:(3): 411–423.
1782:
1750:
1690:
1622:
1566:
1565:
1563:
1560:
1559:
1558:
1553:
1548:
1542:
1541:
1525:
1522:
1518:Fezouata Biota
1471:Lower Cambrian
1447:Czech Republic
1428:Georgina Basin
1359:paleontologist
1350:
1347:
1254:
1253:
1236:
1218:
1206:
1200:
1199:
1196:
1195:
1191:
1190:
1187:
1186:
1182:
1181:
1178:
1177:
1173:
1172:
1169:
1168:
1164:
1163:
1160:
1159:
1152:
1149:
1148:
1145:
1144:
1134:
1129:
1127:
1124:
1123:
1120:
1119:
1115:
1114:
1111:
1110:
1095:
1092:
1091:
1088:
1087:
1083:
1082:
1079:
1078:
1071:
1068:
1067:
1064:
1063:
1059:
1058:
1055:
1054:
1045:
1042:
1041:
1038:
1037:
1030:
1025:
1023:
1018:
1016:
1011:
1009:
1004:
1002:
999:
998:
995:
994:
985:
980:
978:
975:
974:
971:
970:
963:
958:
956:
951:
950:
949:
948:
947:
907:Burgessochaeta
745:worm, and its
726:" of a modern
714:
713:Classification
711:
648:
645:
634:
627:
626:
618:
611:
610:
602:
595:
594:
593:
592:
591:
567:
564:
542:As known from
484:
483:
475:
464:
461:Ventro-lateral
459:
454:
449:
444:
439:
438:
431:
430:
429:
428:
426:
423:
397:
394:
381:
378:
311:
310:
309:
308:
296:
290:Conway Morris
284:
276:
268:
256:
245:
244:
240:
239:
225:
221:
220:
208:
204:
203:
195:
191:
190:
188:Lophotrochozoa
185:
181:
180:
175:
171:
170:
165:
161:
160:
147:
146:
138:
137:
129:
128:
109:
104:
99:
94:
89:
84:
79:
74:
69:
64:
59:
54:
53:
31:Early Cambrian
28:
15:
13:
10:
9:
6:
4:
3:
2:
3528:
3517:
3514:
3512:
3509:
3507:
3506:Wheeler Shale
3504:
3502:
3499:
3497:
3494:
3492:
3489:
3487:
3484:
3482:
3479:
3477:
3474:
3472:
3469:
3467:
3464:
3462:
3459:
3458:
3456:
3439:
3434:
3430:
3426:
3421:
3417:
3413:
3408:
3404:
3400:
3395:
3391:
3387:
3382:
3378:
3374:
3369:
3365:
3360:
3354:
3350:
3345:
3339:
3335:
3334:
3332:
3330:
3326:
3322:
3317:
3309:
3308:
3303:
3299:
3295:
3291:
3287:
3285:
3279:
3278:
3274:
3265:
3261:
3257:
3253:
3249:
3245:
3241:
3237:
3233:
3226:
3223:
3218:
3214:
3210:
3206:
3199:
3197:
3188:
3185:
3180:
3176:
3172:
3168:
3164:
3160:
3153:
3150:
3145:
3141:
3137:
3133:
3129:
3125:
3118:
3115:
3110:
3106:
3102:
3098:
3094:
3090:
3086:
3082:
3081:
3073:
3071:
3067:
3062:
3056:
3052:
3048:
3041:
3039:
3035:
3026:
3023:
3018:
3014:
3009:
3004:
3000:
2996:
2992:
2985:
2983:
2981:
2977:
2972:
2968:
2964:
2960:
2956:
2952:
2948:
2944:
2936:
2933:
2928:
2924:
2920:
2916:
2912:
2908:
2904:
2900:
2896:
2889:
2886:
2881:
2877:
2873:
2869:
2865:
2861:
2857:
2853:
2849:
2847:
2838:
2835:
2830:
2826:
2819:
2816:
2811:
2807:
2803:
2799:
2795:
2791:
2787:
2783:
2780:(5): 451–65.
2779:
2775:
2768:
2765:
2760:
2754:
2750:
2746:
2740:
2737:
2732:
2728:
2721:
2718:
2713:
2709:
2705:
2701:
2697:
2693:
2689:
2682:
2679:
2674:
2670:
2666:
2662:
2655:
2652:
2641:on 2012-12-08
2640:
2636:
2632:
2628:
2624:
2620:
2616:
2612:
2608:
2604:
2602:
2593:
2590:
2585:
2581:
2577:
2573:
2569:
2565:
2561:
2557:
2550:
2548:
2546:
2542:
2531:
2527:
2523:
2519:
2514:
2509:
2505:
2501:
2497:
2490:
2487:
2482:
2478:
2474:
2470:
2466:
2462:
2458:
2454:
2453:
2445:
2442:
2431:on 2011-08-13
2430:
2426:
2422:
2418:
2414:
2410:
2406:
2402:
2398:
2394:
2392:
2383:
2381:
2377:
2372:
2368:
2364:
2363:Walcott, C.D.
2358:
2356:
2352:
2341:
2337:
2333:
2329:
2324:
2319:
2315:
2311:
2307:
2300:
2297:
2292:
2288:
2283:
2278:
2274:
2270:
2266:
2262:
2261:Palaeontology
2258:
2256:
2247:
2245:
2243:
2239:
2233:
2228:
2224:
2220:
2216:
2212:
2208:
2204:
2200:
2193:
2190:
2185:
2181:
2177:
2173:
2169:
2165:
2161:
2157:
2153:
2149:
2145:
2141:
2134:
2132:
2130:
2126:
2121:
2117:
2113:
2109:
2104:
2099:
2095:
2091:
2087:
2083:
2076:
2074:
2072:
2068:
2063:
2062:Burgess Shale
2059:
2053:
2050:
2045:
2041:
2036:
2031:
2027:
2023:
2019:
2015:
2011:
2009:
2005:
1996:
1994:
1992:
1990:
1986:
1981:
1977:
1972:
1967:
1963:
1959:
1955:
1951:
1950:Palaeontology
1947:
1945:
1936:
1934:
1932:
1930:
1928:
1926:
1924:
1922:
1920:
1918:
1916:
1914:
1912:
1910:
1906:
1901:
1897:
1893:
1889:
1885:
1881:
1877:
1873:
1869:
1862:
1860:
1858:
1856:
1854:
1852:
1850:
1848:
1846:
1844:
1840:
1835:
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1827:
1823:
1818:
1813:
1809:
1805:
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1793:
1786:
1783:
1779:(3): 359–366.
1778:
1774:
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1639:"Articulated
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1510:Phyllopod bed
1507:
1502:
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1488:
1484:
1480:
1476:
1472:
1469:Stage of the
1468:
1464:
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1456:
1455:Emu Bay Shale
1452:
1448:
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1425:
1421:
1417:
1416:Phyllopod bed
1413:
1409:
1404:
1402:
1398:
1394:
1390:
1386:
1382:
1376:
1371:
1367:
1366:Burgess Shale
1363:
1360:
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1282:
1278:
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1247:
1246:
1245:Thambetolepis
1241:
1237:
1234:
1230:
1226:
1223:
1222:Sirius Passet
1219:
1216:
1213:The earliest
1212:
1211:
1198:
1197:
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1188:
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1179:
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1100:Thambetolepis
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486:
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456:Lower lateral
451:Upper lateral
435:
424:
422:
416:
412:
410:
406:
402:
395:
393:
391:
390:Burgess Shale
387:
379:
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371:
366:
364:
360:
353:
349:
345:
338:
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323:
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260:
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252:
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246:
241:
237:Walcott, 1911
234:
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226:
223:
222:
218:Walcott, 1911
215:
209:
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205:
202:
196:
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184:Superphylum:
183:
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172:
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162:
157:
152:
148:
144:
139:
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120:
119:Late Cambrian
112:
107:
102:
97:
92:
87:
82:
77:
72:
67:
62:
57:
51:
48:520–505
44:
40:
36:
32:
26:
22:
19:
3328:
3305:
3294:the original
3289:
3283:
3239:
3235:
3225:
3208:
3204:
3195:
3187:
3165:(1): 71–74.
3162:
3158:
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2660:
2654:
2643:. Retrieved
2639:the original
2610:
2606:
2600:
2592:
2559:
2555:
2533:. Retrieved
2503:
2499:
2489:
2456:
2450:
2444:
2433:. Retrieved
2429:the original
2400:
2396:
2390:
2370:
2366:
2343:. Retrieved
2313:
2309:
2299:
2264:
2260:
2254:
2206:
2202:
2192:
2151:
2148:Paleobiology
2147:
2146:. Walcott".
2143:
2139:
2085:
2081:
2061:
2052:
2017:
2013:
2007:
2003:
1953:
1949:
1943:
1875:
1871:
1867:
1799:
1795:
1785:
1776:
1772:
1768:
1710:
1706:
1650:
1646:
1640:
1584:
1580:
1556:Lystrosaurus
1514:
1503:
1499:W. corrugata
1498:
1495:W. corrugata
1494:
1489:and on most
1482:
1432:
1423:
1411:
1405:
1397:Aphroditidae
1392:
1353:
1352:
1342:
1340:
1335:
1333:
1328:
1324:
1317:
1310:
1303:
1291:
1289:
1284:
1276:
1273:aplacophoran
1261:
1257:
1255:
1249:
1243:
1154:
1137:
1136:
1098:
1097:
1074:
1073:
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1047:
1032:
987:
965:
938:
930:
919:
914:
910:
906:
902:
898:
896:
887:
884:segmentation
876:
873:Phyllodocida
864:
856:
854:
848:
835:
807:
801:
796:
790:
772:
765:
759:
735:
731:
716:
690:
687:bellicostata
683:
679:
676:bellicostata
672:
664:
662:
656:
636:
620:
604:
582:
579:W. corrugata
578:
570:
569:
550:
543:
541:
510:
495:
488:
414:
413:
400:
399:
385:
383:
373:
367:
351:
336:
335:
325:
316:
315:
314:
303:
298:
291:
286:
278:
270:
263:
258:
251:W. corrugata
250:
231:
230:
213:
142:
24:
18:
3381:iNaturalist
3353:Wikispecies
2745:Gould, S.J.
1587:(5–6): 27.
1370:Miaolingian
1229:brachiopods
1225:lagerstätte
1215:halkieriids
1156:BRACHIOPODA
1141:evangelista
935:halkieriids
816:halkieriids
539:sclerites.
409:rectangular
380:Description
359:Wiwaxy Peak
3455:Categories
3307:Pharyngula
2831:: 119–144.
2645:2008-08-05
2535:2006-12-02
2435:2008-08-06
2373:: 109–144.
2345:2006-08-20
1562:References
1435:Chengjiang
1401:Polynoidae
1385:polychaete
1349:Occurrence
1296:polychaete
1233:lophophore
1106:halkieriid
990:halkieriid
988:"Siberian
822:bristles (
787:hyolithids
740:polychaete
724:stem group
697:to scrape
669:brachiopod
556:iridescent
370:Halwaxiida
271:W. papilio
259:W. foliosa
214:Wiwaxiidae
123:Ordovician
3264:129319753
2971:128691091
2927:131422014
2880:129654292
2397:BioEssays
2223:0962-8452
2120:131557288
2098:CiteSeerX
1826:0022-3360
1713:: 14810.
1617:164217158
1387:group of
1139:Halkieria
943:cladogram
832:follicles
820:chitinous
792:Halkieria
780:molluscan
760:In 1985,
747:sclerites
685:Diraphora
674:Diraphora
655:Juvenile
518:mammalian
514:follicles
498:sclerites
425:Sclerites
372:contains
200: (?)
174:Kingdom:
168:Eukaryota
3338:Wikidata
3017:56212659
2810:53646959
2802:20173022
2747:(1990).
2733:: 39–68.
2667:: 1–10.
2635:32940079
2627:12833382
2530:38973589
2522:21680421
2425:29130876
2417:17120226
2340:41959378
2332:21680420
2291:84616434
2184:88100863
2044:22915671
1980:84616434
1834:55050961
1745:26443243
1685:24717918
1653:: 4643.
1609:31129730
1524:See also
1467:Botomian
1465:, upper
1034:ANNELIDA
967:MOLLUSCA
699:bacteria
566:Ontogeny
545:Marrella
502:crescent
348:molluscs
344:annelids
330:Cambrian
287:W. herka
243:Species
207:Family:
198:Mollusca
194:Phylum:
178:Animalia
164:Domain:
3433:ZooBank
3412:4987728
3399:1023354
3373:2318801
3359:Wiwaxia
3344:Q132565
3329:Wiwaxia
3244:Bibcode
3205:Lethaia
3196:Wiwaxia
3167:Bibcode
3159:Geology
3132:Bibcode
3109:4326311
3089:Bibcode
3038:Wiwaxia
3034:Eldonia
2951:Bibcode
2907:Bibcode
2895:Wiwaxia
2860:Bibcode
2846:Wiwaxia
2782:Bibcode
2774:PALAIOS
2700:Bibcode
2692:Lethaia
2688:Wiwaxia
2564:Bibcode
2481:4324153
2461:Bibcode
2269:Bibcode
2255:Wiwaxia
2232:1689164
2176:2400789
2156:Bibcode
2090:Bibcode
2035:3441091
2008:Wiwaxia
1958:Bibcode
1944:Wiwaxia
1900:2396338
1880:Bibcode
1804:Bibcode
1769:Wiwaxia
1736:4595806
1715:Bibcode
1676:3982170
1655:Bibcode
1641:Wiwaxia
1589:Bibcode
1483:Wiwaxia
1439:Guizhou
1424:Wiwaxia
1412:Wiwaxia
1389:annelid
1354:Wiwaxia
1343:Wiwaxia
1336:Wiwaxia
1329:Wiwaxia
1325:Wiwaxia
1318:Wiwaxia
1311:Wiwaxia
1304:Wiwaxia
1300:annelid
1292:Wiwaxia
1285:Wiwaxia
1277:Wiwaxia
1269:radulas
1262:Wiwaxia
1250:Wiwaxia
1075:Wiwaxia
1050:Canadia
939:Wiwaxia
931:Wiwaxia
920:Wiwaxia
915:Wiwaxia
911:Canadia
903:Wiwaxia
899:Wiwaxia
892:annelid
888:Wiwaxia
877:Wiwaxia
865:Wiwaxia
857:Wiwaxia
836:Wiwaxia
808:Wiwaxia
797:Wiwaxia
773:Wiwaxia
766:Wiwaxia
743:annelid
736:Wiwaxia
732:Wiwaxia
691:Wiwaxia
680:Wiwaxia
665:Wiwaxia
647:Ecology
587:molting
571:Wiwaxia
551:Canadia
533:monocot
525:optical
506:bananas
489:Wiwaxia
415:Wiwaxia
401:Wiwaxia
374:Wiwaxia
352:Wiwaxia
337:Wiwaxia
326:Wiwaxia
317:Wiwaxia
294:, 2015
266:, 2014
232:Wiwaxia
224:Genus:
43:Wuliuan
39:Stage 3
25:Wiwaxia
3386:355982
3262:
3107:
3080:Nature
3057:
3015:
2969:
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2808:
2800:
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2452:Nature
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1307:'s
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1258:et al.
927:radula
923:'s
880:'s
860:'s
839:'s
828:genera
783:radula
776:'s
769:'s
755:phylum
751:elytra
574:'s
468:
446:Dorsal
418:'s
355:'s
340:'s
306:, 2024
304:et al.
292:et al.
264:et al.
125:period
3394:IRMNG
3260:S2CID
3201:(PDF)
3105:S2CID
3043:(PDF)
3013:S2CID
2967:S2CID
2923:S2CID
2876:S2CID
2806:S2CID
2798:JSTOR
2631:S2CID
2584:55950
2580:JSTOR
2526:S2CID
2477:S2CID
2421:S2CID
2391:worms
2336:S2CID
2287:S2CID
2180:S2CID
2172:JSTOR
2116:S2CID
1976:S2CID
1896:JSTOR
1830:S2CID
1613:S2CID
1475:Sinsk
1281:clade
1240:genus
869:order
824:setae
812:taxon
728:taxon
441:Spine
322:genus
320:is a
262:Yang
3425:7314
3368:GBIF
3055:ISBN
3036:and
2753:ISBN
2623:PMID
2518:PMID
2413:PMID
2328:PMID
2219:ISSN
2040:PMID
2006:and
1822:ISSN
1741:PMID
1681:PMID
1605:PMID
1399:and
909:and
707:rake
695:rasp
548:and
527:and
521:hair
403:was
396:Body
302:Sun
121:and
56:Preęž’
3252:doi
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