Project 4796: T. J. Cotton, R. A. Fortey. 2005. Comparative morphology and relationships of the Agnostida. Crustacea and Arthropod Relationships. 16:95-136.
Abstract
The relationships of the agnostid trilobites have been controversial. They have been claimed as highly derived, neotenously-derived trilobites on the one hand, or as arthropods close to the stem group of crustaceans on the other. On the former view, their distinctive autapomorphies are regarded as specialisations related to their mode of life; on the latter, emphasis is placed on the differences from polymerid trilobites as indicating a separated erivation. We consider it necessary to include Eodiscina in any assessment of agnostid relationships. Previously suggested synapomorphies uniting crustaceans and agnostids to the exclusion of trilobites are reviewed, and the majority is rejected. A number of new synapomorphies uniting agnostids with all, or some eodiscinids are described. These characters are tested in the context of a cladistic analysis of 79 eodiscinid and 3 agnostid taxa. We conclude that agnostids are deeply nested within the eodiscinids. The eodiscinid family Weymouthiidae is strongly supported as sister taxon to the Agnostina. Several supposed agnostid autapomorphies are found to be synapomorphies shared with one or more eodiscinid group. At least as far as exoskeletal characters are concerned, the supposed distinctiveness of agnostids has been over-emphasised. To assert non-trilobite relationships of agnostids would require implausible levels of homoplasy.Read the article »
Article DOI: 10.1201/9781420037548.ch5
Project DOI: 10.7934/P4796, http://dx.doi.org/10.7934/P4796
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 9985 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 123 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 299 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:123/0 |
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MorphoBank Project 4796
MorphoBank Project 4796
- Creation Date:
31 July 2023 - Publication Date:
01 August 2023 - Project views: 4009
- Media downloads: 1
Authors' Institutions
- Natural History Museum, London
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Shreya Jariwala Project Administrator | 85 | 6 | 6 | 123 | 0 | 0 | 9985 (8194, 0, 1791) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29403' (85 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Abakolia minutus Last Modified in 07/31/23 | 2 | 101 | 98 | 0 | 23 | 0 | 0 | 1 |
[2] † Abakolia pauca Last Modified in 07/31/23 | 10 | 97 | 90 | 0 | 23 | 0 | 0 | 1 |
[3] † Acidiscus birdi Last Modified in 07/31/23 | 8 | 96 | 94 | 0 | 21 | 0 | 0 | 1 |
[4] † Acidiscus theristes Last Modified in 07/31/23 | 3 | 105 | 101 | 0 | 19 | 0 | 0 | 1 |
[5] † Acimetopus bilobatus Last Modified in 07/31/23 | 8 | 92 | 91 | 0 | 24 | 0 | 0 | 1 |
[6] † Alaskadiscus spinosus Last Modified in 07/31/23 | 2 | 107 | 104 | 0 | 17 | 0 | 0 | 1 |
[7] † Analox bipunctata Last Modified in 07/31/23 | 12 | 86 | 83 | 0 | 28 | 0 | 0 | 1 |
[8] † Bathydiscus dolichometopus Last Modified in 07/31/23 | 9 | 89 | 86 | 0 | 28 | 0 | 0 | 1 |
[9] † Bolboparia superba Last Modified in 07/31/23 | 12 | 94 | 93 | 0 | 18 | 0 | 0 | 1 |
[10] † Calodiscus lobatus Last Modified in 07/31/23 | 8 | 103 | 95 | 0 | 20 | 0 | 0 | 1 |
[11] † Cephalopyge notabilis Last Modified in 07/31/23 | 9 | 87 | 84 | 0 | 30 | 0 | 0 | 1 |
[12] † Chelediscus acifer Last Modified in 07/31/23 | 0 | 99 | 97 | 0 | 26 | 0 | 0 | 1 |
[13] † Chelediscus chathamensis Last Modified in 07/31/23 | 14 | 87 | 84 | 0 | 25 | 0 | 0 | 1 |
[14] † Cobboldites comleyensis Last Modified in 07/31/23 | 9 | 86 | 84 | 0 | 30 | 0 | 0 | 1 |
[15] † Cobboldites itsariensis Last Modified in 07/31/23 | 10 | 88 | 82 | 0 | 31 | 0 | 0 | 1 |
[16] † Dawsonia bohemicus Last Modified in 07/31/23 | 6 | 94 | 92 | 0 | 25 | 0 | 0 | 1 |
[17] † Dawsonia dawsoni Last Modified in 07/31/23 | 2 | 97 | 95 | 0 | 26 | 0 | 0 | 1 |
[18] † Delgadella caudatus Last Modified in 07/31/23 | 9 | 95 | 91 | 0 | 23 | 0 | 0 | 1 |
[19] † Delgadella lenaicus Last Modified in 07/31/23 | 2 | 98 | 97 | 0 | 24 | 0 | 0 | 1 |
[20] † Delgadella amouslekensis Last Modified in 07/31/23 | 16 | 86 | 84 | 0 | 23 | 0 | 0 | 1 |
[21] † Dicerodiscus tsunyiensis Last Modified in 07/31/23 | 19 | 86 | 84 | 0 | 20 | 0 | 0 | 1 |
[22] † Egyngolia willochra Last Modified in 07/31/23 | 9 | 104 | 100 | 0 | 14 | 0 | 0 | 1 |
[23] † Egyngolia obtusa Last Modified in 07/31/23 | 4 | 109 | 102 | 0 | 17 | 0 | 0 | 1 |
[24] † Egyngolia zaicevi Last Modified in 07/31/23 | 45 | 59 | 57 | 0 | 21 | 0 | 0 | 1 |
[25] † Ekwipagetia marginata Last Modified in 07/31/23 | 9 | 106 | 100 | 0 | 14 | 0 | 0 | 1 |
[26] † Ekwipagetia plicofimbria Last Modified in 07/31/23 | 8 | 105 | 100 | 0 | 15 | 0 | 0 | 1 |
[27] † Eodiscus borealis Last Modified in 07/31/23 | 3 | 100 | 96 | 0 | 24 | 0 | 0 | 1 |
[28] † Eodiscus scanicus Last Modified in 07/31/23 | 2 | 108 | 98 | 0 | 23 | 0 | 0 | 1 |
[29] † Hebediscina sardoa Last Modified in 07/31/23 | 8 | 104 | 99 | 0 | 16 | 0 | 0 | 1 |
[30] † Hebediscina blagonravovi Last Modified in 07/31/23 | 16 | 97 | 90 | 0 | 16 | 0 | 0 | 1 |
[31] † Hebediscina yuqingensis Last Modified in 07/31/23 | 12 | 104 | 99 | 0 | 12 | 0 | 0 | 1 |
[32] † Hebediscus attleborensis Last Modified in 07/31/23 | 16 | 86 | 84 | 0 | 23 | 0 | 0 | 1 |
[33] † Helepagetia bitruncula Last Modified in 07/31/23 | 8 | 107 | 101 | 0 | 14 | 0 | 0 | 1 |
[34] † Jinghediscus nummularius Last Modified in 07/31/23 | 11 | 93 | 89 | 0 | 23 | 0 | 0 | 1 |
[35] † Kiskinella cristata Last Modified in 07/31/23 | 11 | 99 | 98 | 0 | 14 | 0 | 0 | 1 |
[36] † Korobovia ocellata Last Modified in 07/31/23 | 8 | 97 | 94 | 0 | 21 | 0 | 0 | 1 |
[37] † Lenadiscus unicus Last Modified in 07/31/23 | 15 | 96 | 91 | 0 | 16 | 0 | 0 | 1 |
[38] † Leptochilodiscus punctulatus Last Modified in 07/31/23 | 8 | 89 | 85 | 0 | 30 | 0 | 0 | 1 |
[39] † Leptochilodiscus succinctus Last Modified in 07/31/23 | 1 | 100 | 95 | 0 | 27 | 0 | 0 | 1 |
[40] † Litometopus longispinus Last Modified in 07/31/23 | 9 | 87 | 86 | 0 | 28 | 0 | 0 | 1 |
[41] † Luvsanodiscus gammatus Last Modified in 07/31/23 | 0 | 104 | 101 | 0 | 22 | 0 | 0 | 1 |
[42] † Macannaia maladensis Last Modified in 07/31/23 | 1 | 115 | 110 | 0 | 12 | 0 | 0 | 1 |
[43] † Mallagnostus desideratus Last Modified in 07/31/23 | 47 | 53 | 52 | 0 | 24 | 0 | 0 | 1 |
[44] † Mallagnostus limbatus Last Modified in 07/31/23 | 8 | 87 | 84 | 0 | 31 | 0 | 0 | 1 |
[45] † Mallagnostus llarenai Last Modified in 07/31/23 | 6 | 96 | 91 | 0 | 26 | 0 | 0 | 1 |
[46] † Meniscuchus menetus Last Modified in 07/31/23 | 8 | 92 | 88 | 0 | 27 | 0 | 0 | 1 |
[47] † Meniscuchus nanus Last Modified in 07/31/23 | 12 | 85 | 84 | 0 | 27 | 0 | 0 | 1 |
[48] † Natalina incita Last Modified in 07/31/23 | 15 | 96 | 90 | 0 | 18 | 0 | 0 | 1 |
[49] † Natalina dilata Last Modified in 07/31/23 | 20 | 89 | 86 | 0 | 17 | 0 | 0 | 1 |
[50] † Neocobboldia dentata Last Modified in 07/31/23 | 3 | 99 | 97 | 0 | 23 | 0 | 0 | 1 |
[51] † Neopagetina rjonsnitzkii Last Modified in 07/31/23 | 9 | 104 | 101 | 0 | 13 | 0 | 0 | 1 |
[52] † Ninadiscus strobulatus Last Modified in 07/31/23 | 12 | 94 | 89 | 0 | 22 | 0 | 0 | 1 |
[53] † Oodiscus subgranulatus Last Modified in 07/31/23 | 10 | 88 | 87 | 0 | 26 | 0 | 0 | 1 |
[54] † Opsidiscus bilobatus Last Modified in 07/31/23 | 12 | 102 | 95 | 0 | 16 | 0 | 0 | 1 |
[55] † Opsidiscus microspinus Last Modified in 07/31/23 | 1 | 112 | 107 | 0 | 15 | 0 | 0 | 1 |
[56] † Opsidiscus longispinus Last Modified in 07/31/23 | 40 | 71 | 69 | 0 | 14 | 0 | 0 | 1 |
[57] † Pagetia bootes Last Modified in 07/31/23 | 1 | 111 | 109 | 0 | 13 | 0 | 0 | 1 |
[58] † Pagetia prolata Last Modified in 07/31/23 | 1 | 113 | 110 | 0 | 12 | 0 | 0 | 1 |
[59] † Pagetides elegans Last Modified in 07/31/23 | 1 | 115 | 109 | 0 | 13 | 0 | 0 | 1 |
[60] † Pagetides fragum Last Modified in 07/31/23 | 8 | 106 | 101 | 0 | 14 | 0 | 0 | 1 |
[61] † Pseudocobboldia pulchra Last Modified in 07/31/23 | 10 | 97 | 93 | 0 | 20 | 0 | 0 | 1 |
[62] † Runcinodiscus index Last Modified in 07/31/23 | 8 | 93 | 91 | 0 | 24 | 0 | 0 | 1 |
[63] † Semadiscus sollennis Last Modified in 07/31/23 | 40 | 59 | 58 | 0 | 25 | 0 | 0 | 1 |
[64] † Serrodiscus speciosus Last Modified in 07/31/23 | 1 | 103 | 98 | 0 | 24 | 0 | 0 | 1 |
[65] † Serrodiscus gravestocki Last Modified in 07/31/23 | 11 | 95 | 91 | 0 | 21 | 0 | 0 | 1 |
[66] † Serrodiscus daedalus Last Modified in 07/31/23 | 10 | 95 | 91 | 0 | 22 | 0 | 0 | 1 |
[67] † Serrodiscus ctenoa Last Modified in 07/31/23 | 0 | 101 | 98 | 0 | 25 | 0 | 0 | 1 |
[68] † Sinodiscus shipaiensis Last Modified in 07/31/23 | 0 | 103 | 101 | 0 | 22 | 0 | 0 | 1 |
[69] † Sinodiscus subquadratus Last Modified in 07/31/23 | 8 | 98 | 94 | 0 | 21 | 0 | 0 | 1 |
[70] † Sinopagetia jinnanensis Last Modified in 07/31/23 | 10 | 97 | 96 | 0 | 17 | 0 | 0 | 1 |
[71] † Stigmadiscus stenometopus Last Modified in 07/31/23 | 15 | 86 | 84 | 0 | 24 | 0 | 0 | 1 |
[72] † Tannudiscus altus Last Modified in 07/31/23 | 10 | 89 | 83 | 0 | 30 | 0 | 0 | 1 |
[73] † Tannudiscus balanus Last Modified in 07/31/23 | 0 | 97 | 94 | 0 | 29 | 0 | 0 | 1 |
[74] † Tchernyshevioides ninae Last Modified in 07/31/23 | 8 | 99 | 96 | 0 | 19 | 0 | 0 | 1 |
[75] † Tsunyidiscus niutitangensis Last Modified in 07/31/23 | 1 | 112 | 109 | 0 | 13 | 0 | 0 | 1 |
[76] † Tsunyidiscus kaiyangensis Last Modified in 07/31/23 | 5 | 112 | 106 | 0 | 12 | 0 | 0 | 1 |
[77] † Tsunyidiscus aclis Last Modified in 07/31/23 | 9 | 107 | 103 | 0 | 11 | 0 | 0 | 1 |
[78] † Tsunyidiscus orientalis Last Modified in 07/31/23 | 1 | 108 | 104 | 0 | 18 | 0 | 0 | 1 |
[79] † Tsunyidiscus longquanensis Last Modified in 07/31/23 | 0 | 107 | 104 | 0 | 19 | 0 | 0 | 1 |
[80] † Weymouthia nobilis Last Modified in 07/31/23 | 27 | 74 | 72 | 0 | 24 | 0 | 0 | 1 |
[81] † Yukonia intermedia Last Modified in 07/31/23 | 1 | 112 | 105 | 0 | 17 | 0 | 0 | 1 |
[82] † Yukonides lacrinus Last Modified in 07/31/23 | 9 | 105 | 98 | 0 | 16 | 0 | 0 | 1 |
[83] † Condylopyge amitina Last Modified in 07/31/23 | 2 | 96 | 94 | 0 | 27 | 0 | 0 | 1 |
[84] † Peronopsis roddyi Last Modified in 07/31/23 | 2 | 95 | 92 | 0 | 29 | 0 | 0 | 1 |
[85] † Ptychagnostus gibbus Last Modified in 07/31/23 | 1 | 99 | 97 | 0 | 25 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 4009 | |
Project overview | 290 | |
Documents list | 136 | |
Matrix views | 147 | Matrix landing page (141 views); Cotton and Fortey 2005 (6 views); |
Media views | 999 | Media search (456 views); M890501 (84 views); M890502 (78 views); M890503 (75 views); M890504 (82 views); M890505 (143 views); M890506 (81 views); |
Views for media list | 165 | |
Taxon list | 1438 | |
Specimen list | 729 | |
Bibliography | 105 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 1 | |
Media downloads | 1 | M890505 (1 download); |