Project 4817: C. Aria, J. Caron. 2019. A middle Cambrian arthropod with chelicerae and proto-book gills. Nature. 573 (7775):586-589.
Abstract
The chelicerates are a ubiquitous and speciose group of animals that has a considerable ecological effect on modern terrestrial ecosystems—notably as predators of insects and also, for instance, as decomposers¹. The fossil record shows that chelicerates diversified early in the marine ecosystems of the Palaeozoic era, by at least the Ordovician period². However, the timing of chelicerate origins and the type of body plan that characterized the earliest members of this group have remained controversial. Although megacheirans3–5 have previously been interpreted as chelicerate-like, and habeliidans⁶ (including Sanctacaris7,8) have been suggested to belong to their immediate stem lineage, evidence for the specialized feeding appendages (chelicerae) that are diagnostic of the chelicerates has been lacking. Here we use exceptionally well-preserved and abundant fossil material from the middle Cambrian Burgess Shale (Marble Canyon, British Columbia, Canada) to show that Mollisonia plenovenatrix sp. nov. possessed robust but short chelicerae that were placed very anteriorly, between the eyes. This suggests that chelicerae evolved a specialized feeding function early on, possibly as a modification of short antennules. The head also encompasses a pair of large compound eyes, followed by three pairs of long, uniramous walking legs and three pairs of stout, gnathobasic masticatory appendages; this configuration links habeliidans with euchelicerates (‘true’ chelicerates, excluding the sea spiders). The trunk ends in a four-segmented pygidium and bears eleven pairs of identical limbs, each of which is composed of three broad lamellate exopod flaps, and endopods are either reduced or absent. These overlapping exopod flaps resemble euchelicerate book gills, although they lack the diagnostic operculum⁹. In addition, the eyes of M. plenovenatrix were innervated by three optic neuropils, which strengthens the view that a complex malacostracan-like visual system10,11 might have been plesiomorphic for all crown euarthropods. These fossils thus show that chelicerates arose alongside mandibulates¹² as benthic micropredators, at the heart of the Cambrian explosion.Read the article »
Article DOI: 10.1038/s41586-019-1525-4
Project DOI: 10.7934/P4817, http://dx.doi.org/10.7934/P4817
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 23046 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 267 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 579 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:267/0 |
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MorphoBank Project 4817
MorphoBank Project 4817
- Creation Date:
07 August 2023 - Publication Date:
16 August 2023 - Project views: 4610
- Matrix downloads: 1
This research
supported by
Authors' Institutions
- Chinese Academy of Sciences
- University of Toronto
- Royal Ontario Museum
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Shreya Jariwala Project Administrator | 101 | 7 | 7 | 267 | 0 | 0 | 23046 (12424, 0, 10622) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29423' (101 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Jianshanopodia Last Modified in 08/07/23 | 23 | 33 | 33 | 0 | 211 | 0 | 0 | 1 |
[2] † Megadictyon Last Modified in 08/07/23 | 25 | 30 | 30 | 0 | 212 | 0 | 0 | 1 |
[3] † Opabinia Last Modified in 08/07/23 | 36 | 56 | 56 | 0 | 175 | 0 | 0 | 1 |
[4] † Anomalocaris Last Modified in 08/07/23 | 27 | 62 | 62 | 0 | 178 | 0 | 0 | 1 |
[5] † Hurdia Last Modified in 08/09/23 | 51 | 55 | 55 | 0 | 161 | 0 | 0 | 1 |
[6] † Aegirocassis Last Modified in 08/07/23 | 64 | 46 | 46 | 0 | 157 | 0 | 0 | 1 |
[7] † Schinderhannes Last Modified in 08/09/23 | 80 | 40 | 40 | 0 | 147 | 0 | 0 | 1 |
[8] † Surusicaris Last Modified in 08/09/23 | 43 | 62 | 62 | 0 | 162 | 0 | 0 | 1 |
[9] † Isoxys Last Modified in 08/09/23 | 98 | 67 | 63 | 0 | 106 | 0 | 0 | 1 |
[10] † Yohoia Last Modified in 08/09/23 | 56 | 132 | 132 | 0 | 79 | 0 | 0 | 1 |
[11] † Fortiforceps Last Modified in 08/09/23 | 65 | 126 | 126 | 0 | 76 | 0 | 0 | 1 |
[12] † Jianfengia Last Modified in 08/09/23 | 76 | 118 | 118 | 0 | 73 | 0 | 0 | 1 |
[13] † Sklerolibyon Last Modified in 08/09/23 | 91 | 108 | 108 | 0 | 68 | 0 | 0 | 1 |
[14] † Parapeytoia Last Modified in 08/09/23 | 141 | 70 | 70 | 0 | 56 | 0 | 0 | 1 |
[15] † Haikoucaris Last Modified in 08/09/23 | 97 | 101 | 101 | 0 | 69 | 0 | 0 | 1 |
[16] † Leanchoiliidae Last Modified in 08/09/23 | 38 | 155 | 152 | 0 | 77 | 0 | 0 | 1 |
[17] † Kiisortoqia Last Modified in 08/09/23 | 76 | 115 | 115 | 0 | 76 | 0 | 0 | 1 |
[18] † Kuamaia Last Modified in 08/09/23 | 56 | 131 | 129 | 0 | 82 | 0 | 0 | 1 |
[19] † Kwanyinaspis Last Modified in 08/09/23 | 61 | 121 | 121 | 0 | 85 | 0 | 0 | 1 |
[20] † Marrella Last Modified in 08/09/23 | 36 | 119 | 119 | 0 | 112 | 0 | 0 | 1 |
[21] † Burgessia Last Modified in 08/07/23 | 76 | 93 | 93 | 0 | 98 | 0 | 0 | 1 |
[22] † Emeraldella Last Modified in 08/09/23 | 48 | 139 | 139 | 0 | 80 | 0 | 0 | 1 |
[23] † Sidneyia Last Modified in 08/09/23 | 45 | 142 | 142 | 0 | 80 | 0 | 0 | 1 |
[24] † Aglaspidida Last Modified in 08/07/23 | 73 | 110 | 110 | 0 | 84 | 0 | 0 | 1 |
[25] † Olenoides Last Modified in 08/09/23 | 23 | 153 | 153 | 0 | 91 | 0 | 0 | 1 |
[26] † Hongshiyanaspis Last Modified in 08/09/23 | 37 | 139 | 139 | 0 | 91 | 0 | 0 | 1 |
[27] † Naraoia Last Modified in 08/09/23 | 25 | 146 | 145 | 0 | 97 | 0 | 0 | 1 |
[28] † Xandarella Last Modified in 08/09/23 | 47 | 135 | 135 | 0 | 85 | 0 | 0 | 1 |
[29] † Pycnogonida Last Modified in 08/09/23 | 12 | 117 | 117 | 0 | 138 | 0 | 0 | 1 |
[30] † Sanctacaris Last Modified in 08/09/23 | 60 | 122 | 122 | 0 | 85 | 0 | 0 | 1 |
[31] † Habelia Last Modified in 08/09/23 | 34 | 139 | 138 | 0 | 95 | 0 | 0 | 1 |
[32] † Mollisonia Last Modified in 08/09/23 | 60 | 134 | 133 | 0 | 74 | 0 | 0 | 1 |
[33] † Offacolus Last Modified in 08/09/23 | 64 | 130 | 130 | 0 | 73 | 0 | 0 | 1 |
[34] † Dibasterium Last Modified in 08/09/23 | 70 | 126 | 126 | 0 | 71 | 0 | 0 | 1 |
[35] † Weinbergina Last Modified in 08/09/23 | 78 | 116 | 116 | 0 | 73 | 0 | 0 | 1 |
[36] Limulus Last Modified in 08/07/23 | 2 | 185 | 185 | 0 | 80 | 0 | 0 | 1 |
[37] † Chasmataspis Last Modified in 08/09/23 | 83 | 113 | 112 | 0 | 72 | 0 | 0 | 1 |
[38] Megalograptus Last Modified in 08/07/23 | 46 | 139 | 136 | 0 | 85 | 0 | 0 | 1 |
[39] Scorpiones Last Modified in 08/07/23 | 0 | 179 | 177 | 0 | 90 | 0 | 0 | 1 |
[40] Pseudoscorpiones Last Modified in 08/07/23 | 9 | 160 | 159 | 0 | 99 | 0 | 0 | 1 |
[41] Opiliones Last Modified in 08/07/23 | 3 | 166 | 164 | 0 | 100 | 0 | 0 | 1 |
[42] † Palpigradi Last Modified in 08/09/23 | 8 | 152 | 152 | 0 | 107 | 0 | 0 | 1 |
[43] Solifugae Last Modified in 08/07/23 | 9 | 159 | 158 | 0 | 100 | 0 | 0 | 1 |
[44] Ricinulei Last Modified in 08/07/23 | 9 | 160 | 159 | 0 | 99 | 0 | 0 | 1 |
[45] † Haptopoda Last Modified in 08/09/23 | 26 | 149 | 149 | 0 | 92 | 0 | 0 | 1 |
[46] Trigonotarbida Last Modified in 08/07/23 | 17 | 157 | 157 | 0 | 93 | 0 | 0 | 1 |
[47] Thelyphonida Last Modified in 08/07/23 | 1 | 173 | 173 | 0 | 93 | 0 | 0 | 1 |
[48] Schizomida Last Modified in 08/07/23 | 0 | 160 | 160 | 0 | 107 | 0 | 0 | 1 |
[49] † Amblypygi Last Modified in 08/07/23 | 1 | 173 | 171 | 0 | 95 | 0 | 0 | 1 |
[50] Uraraneida Last Modified in 08/07/23 | 42 | 137 | 137 | 0 | 88 | 0 | 0 | 1 |
[51] † Araneae Last Modified in 08/07/23 | 1 | 170 | 169 | 0 | 97 | 0 | 0 | 1 |
[52] † Acari Last Modified in 08/07/23 | 2 | 177 | 166 | 0 | 99 | 0 | 0 | 1 |
[53] † Aquilonifer Last Modified in 08/07/23 | 73 | 106 | 106 | 0 | 88 | 0 | 0 | 1 |
[54] † Shankouia Last Modified in 08/09/23 | 67 | 114 | 114 | 0 | 86 | 0 | 0 | 1 |
[55] † Fuxianhuia Last Modified in 08/09/23 | 67 | 117 | 117 | 0 | 83 | 0 | 0 | 1 |
[56] † Chengjiangocaris Last Modified in 08/09/23 | 64 | 115 | 115 | 0 | 88 | 0 | 0 | 1 |
[57] † Euthycarcinoidea Last Modified in 08/09/23 | 59 | 113 | 113 | 0 | 95 | 0 | 0 | 1 |
[58] † Clypecaris Last Modified in 08/09/23 | 132 | 64 | 64 | 0 | 71 | 0 | 0 | 1 |
[59] † Odaraia Last Modified in 08/09/23 | 117 | 84 | 84 | 0 | 66 | 0 | 0 | 1 |
[60] † Nereocaris Last Modified in 08/09/23 | 149 | 59 | 59 | 0 | 59 | 0 | 0 | 1 |
[61] † Canadaspis Last Modified in 08/07/23 | 97 | 106 | 104 | 0 | 66 | 0 | 0 | 1 |
[62] † Perspicaris Last Modified in 08/09/23 | 136 | 64 | 64 | 0 | 67 | 0 | 0 | 1 |
[63] † Waptia Last Modified in 08/09/23 | 37 | 127 | 127 | 0 | 103 | 0 | 0 | 1 |
[64] † Branchiocaris Last Modified in 08/07/23 | 64 | 113 | 113 | 0 | 90 | 0 | 0 | 1 |
[65] † Tokummia Last Modified in 08/09/23 | 58 | 120 | 119 | 0 | 90 | 0 | 0 | 1 |
[66] † Tanazios Last Modified in 08/09/23 | 61 | 120 | 120 | 0 | 86 | 0 | 0 | 1 |
[67] † Cascolus Last Modified in 08/07/23 | 64 | 130 | 130 | 0 | 73 | 0 | 0 | 1 |
[68] † Arthropleura Last Modified in 08/07/23 | 116 | 80 | 80 | 0 | 71 | 0 | 0 | 1 |
[69] Pauropoda Last Modified in 08/07/23 | 6 | 147 | 147 | 0 | 114 | 0 | 0 | 1 |
[70] Symphyla Last Modified in 08/07/23 | 6 | 147 | 147 | 0 | 114 | 0 | 0 | 1 |
[71] Chilopoda Last Modified in 08/07/23 | 0 | 166 | 164 | 0 | 103 | 0 | 0 | 1 |
[72] Diplopoda Last Modified in 08/07/23 | 2 | 156 | 156 | 0 | 109 | 0 | 0 | 1 |
[73] Ostracoda Last Modified in 08/07/23 | 10 | 160 | 158 | 0 | 99 | 0 | 0 | 1 |
[74] † Argulus Last Modified in 08/07/23 | 20 | 159 | 159 | 0 | 88 | 0 | 0 | 1 |
[75] † Artemia Last Modified in 08/07/23 | 3 | 170 | 170 | 0 | 94 | 0 | 0 | 1 |
[76] Triops Last Modified in 08/09/23 | 0 | 174 | 172 | 0 | 95 | 0 | 0 | 1 |
[77] Copepoda Last Modified in 08/07/23 | 12 | 166 | 166 | 0 | 89 | 0 | 0 | 1 |
[78] † Lepidocaris Last Modified in 08/09/23 | 46 | 142 | 142 | 0 | 79 | 0 | 0 | 1 |
[79] † Cephalocarida Last Modified in 08/09/23 | 7 | 162 | 162 | 0 | 98 | 0 | 0 | 1 |
[80] Remipedia Last Modified in 08/07/23 | 7 | 178 | 174 | 0 | 86 | 0 | 0 | 1 |
[81] † Nahecaris Last Modified in 08/09/23 | 74 | 122 | 122 | 0 | 71 | 0 | 0 | 1 |
[82] † Cinerocaris Last Modified in 08/09/23 | 58 | 132 | 132 | 0 | 77 | 0 | 0 | 1 |
[83] Isopoda Last Modified in 08/07/23 | 5 | 184 | 182 | 0 | 80 | 0 | 0 | 1 |
[84] Euphausiacea Last Modified in 08/07/23 | 7 | 184 | 183 | 0 | 77 | 0 | 0 | 1 |
[85] † Anaspidacea Last Modified in 08/07/23 | 10 | 186 | 183 | 0 | 74 | 0 | 0 | 1 |
[86] Stomatopoda Last Modified in 08/07/23 | 4 | 199 | 198 | 0 | 65 | 0 | 0 | 1 |
[87] Leptostraca Last Modified in 08/09/23 | 7 | 176 | 176 | 0 | 84 | 0 | 0 | 1 |
[88] Collembola Last Modified in 08/07/23 | 6 | 168 | 165 | 0 | 96 | 0 | 0 | 1 |
[89] Zygentoma Last Modified in 08/07/23 | 0 | 176 | 176 | 0 | 91 | 0 | 0 | 1 |
[90] Odonata Last Modified in 08/07/23 | 2 | 168 | 168 | 0 | 97 | 0 | 0 | 1 |
[91] Coleoptera Last Modified in 08/07/23 | 0 | 170 | 169 | 0 | 98 | 0 | 0 | 1 |
[92] Diptera Last Modified in 08/09/23 | 0 | 171 | 170 | 0 | 97 | 0 | 0 | 1 |
[93] Hymenoptera Last Modified in 08/07/23 | 2 | 174 | 173 | 0 | 92 | 0 | 0 | 1 |
[94] † Nematoda Last Modified in 08/09/23 | 0 | 24 | 24 | 0 | 243 | 0 | 0 | 1 |
[95] Priapulida Last Modified in 08/07/23 | 0 | 24 | 24 | 0 | 243 | 0 | 0 | 1 |
[96] † Hallucigenia Last Modified in 08/09/23 | 15 | 32 | 32 | 0 | 220 | 0 | 0 | 1 |
[97] Collinsium Last Modified in 08/07/23 | 26 | 30 | 30 | 0 | 211 | 0 | 0 | 1 |
[98] † Luolishania Last Modified in 08/09/23 | 18 | 29 | 29 | 0 | 220 | 0 | 0 | 1 |
[99] † Aysheaia Last Modified in 08/07/23 | 16 | 31 | 31 | 0 | 220 | 0 | 0 | 1 |
[100] Tardigrada Last Modified in 08/07/23 | 3 | 43 | 42 | 0 | 222 | 0 | 0 | 1 |
[101] Onychophora Last Modified in 08/07/23 | 1 | 45 | 45 | 0 | 221 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 4610 | |
Project overview | 205 | |
Matrix views | 136 | Matrix landing page (128 views); Aria and Caron 2019 (8 views); |
Views for media list | 158 | |
Bibliography | 99 | |
Taxon list | 1859 | |
Specimen list | 927 | |
Media views | 1099 | Media search (467 views); M890559 (90 views); M890560 (76 views); M890561 (150 views); M890562 (80 views); M890563 (78 views); M890564 (76 views); M890565 (82 views); |
Documents list | 127 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 1 | |
Matrix downloads | 1 | Aria and Caron 2019 (1 download); |