Project 4905: T. E. Guensburg, J. Sprinkle, R. Mooi, B. Lefebvre. 2021. Evolutionary significance of the blastozoanEumorphocystisand its pseudo-arms. Journal of Paleontology. 95 (2):327-343.
Abstract
Twelve specimens of Eumorphocystis Branson and Peck, 1940 provide the basis for new findings and a more informed assessment of whether this blastozoan (a group including eocrinoids, blastoids, diploporites, rhombiferans) constitutes the sister taxon to crinoids, as has been recently proposed. Both Eumorphocystis and earliest-known crinoid feeding appendages express longitudinal canals, a demonstrable trait exclusive to these taxa. However, the specimen series studied here shows that Eumorphocystis canals constrict proximally and travel within ambulacrals above the thecal cavity. This relationship is congruent with a documented blastozoan pattern but very unlike earliest crinoid topology. Earliest crinoid arm cavities lie fully beneath floor plates; these expand and merge directly with the main thecal coelomic cavity at thecal shoulders. Other associated anatomical features echo this contrasting comparison. Feeding appendages of Eumorphocystis lack two-tiered cover plates, podial basins/pores, and lateral arm plating, all features of earliest crinoid ‘true arms.’ Eumorphocystis feeding appendages are buttressed by solid block-like plates added during ontogeny at a generative zone below floor plates, a pattern with no known parallel among crinoids. Eumorphocystis feeding appendages express brachioles, erect extensions of floor plates, also unknown among crinoids. These several distinctions point to nonhomology of most feeding appendage anatomy, including longitudinal canals, removing Eumorphocystis and other blastozoans from exclusive relationship with crinoids. Eumorphocystis further differs from crinoids in that thecal plates express diplopores, respiratory structures not present among crinoids, but ubiquitous among certain groups of blastozoans. Phylogenetic analysis places Eumorphocystis as a crownward blastozoan, far removed from crinoids.Read the article »
Article DOI: 10.1017/jpa.2020.84
Project DOI: 10.7934/P4905, http://dx.doi.org/10.7934/P4905
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 940 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 39 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 93 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:39/0 |
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MorphoBank Project 4905
MorphoBank Project 4905
- Creation Date:
03 October 2023 - Publication Date:
23 November 2023 - Project views: 2415
- Matrix downloads: 1
Authors' Institutions
- University of Texas at Austin
- Université de Lyon (University of Lyon)
- California Academy of Sciences
- Field Museum of Natural History
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Shreya Jariwala Project Administrator | 25 | 8 | 8 | 39 | 0 | 0 | 940 (638, 0, 302) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29506' (25 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Stromatocystites pentangularis Last Modified in 10/03/23 | 0 | 19 | 19 | 0 | 20 | 0 | 0 | 1 |
[2] † Kailidiscus chinensis Last Modified in 10/03/23 | 1 | 17 | 17 | 0 | 21 | 0 | 0 | 1 |
[3] † Camptostroma roddyi Last Modified in 10/03/23 | 0 | 21 | 21 | 0 | 18 | 0 | 0 | 1 |
[4] † Totiglobus lloydi Last Modified in 10/03/23 | 0 | 18 | 18 | 0 | 21 | 0 | 0 | 1 |
[5] Pseudedriophus guensburgi Last Modified in 10/03/23 | 2 | 17 | 17 | 0 | 20 | 0 | 0 | 1 |
[6] † Kinzercystis durhami Last Modified in 10/03/23 | 0 | 18 | 18 | 0 | 21 | 0 | 0 | 1 |
[7] † Lepidocystis wanneri Last Modified in 10/03/23 | 2 | 16 | 16 | 0 | 21 | 0 | 0 | 1 |
[8] † Gogia kitchnerensis Last Modified in 10/03/23 | 2 | 16 | 16 | 0 | 21 | 0 | 0 | 1 |
[9] † Rhopalocystis destombesi Last Modified in 10/03/23 | 2 | 18 | 18 | 0 | 19 | 0 | 0 | 1 |
[10] † Macrocystella mairae Last Modified in 10/03/23 | 2 | 17 | 17 | 0 | 20 | 0 | 0 | 1 |
[11] † Hemicosmites pocillum Last Modified in 10/03/23 | 2 | 17 | 17 | 0 | 20 | 0 | 0 | 1 |
[12] † Stephanocrinus gemmiformis Last Modified in 10/03/23 | 1 | 18 | 18 | 0 | 20 | 0 | 0 | 1 |
[13] † Eumorphocystis multiporata Last Modified in 10/03/23 | 0 | 20 | 20 | 0 | 19 | 0 | 0 | 1 |
[14] † Ceratocystis perneri Last Modified in 10/03/23 | 0 | 23 | 23 | 0 | 16 | 0 | 0 | 1 |
[15] † Aethocrinus moorei Last Modified in 10/03/23 | 2 | 35 | 35 | 0 | 2 | 0 | 0 | 1 |
[16] † Alphacrinus mansfieldi Last Modified in 10/03/23 | 2 | 35 | 35 | 0 | 2 | 0 | 0 | 1 |
[17] † Apektocrinus ubaghsi Last Modified in 10/03/23 | 0 | 36 | 36 | 0 | 3 | 0 | 0 | 1 |
[18] † Athenacrinus broweri Last Modified in 10/03/23 | 0 | 37 | 37 | 0 | 2 | 0 | 0 | 1 |
[19] † Carabocrinus treadwelli Last Modified in 10/03/23 | 1 | 35 | 35 | 0 | 3 | 0 | 0 | 1 |
[20] † Gaurocrinus nealli Last Modified in 10/03/23 | 2 | 33 | 33 | 0 | 4 | 0 | 0 | 1 |
[21] † Hybocrinus nitidus Last Modified in 10/03/23 | 0 | 39 | 39 | 0 | 0 | 0 | 0 | 1 |
[22] † Eknomocrinus wahwahensi Last Modified in 10/03/23 | 4 | 33 | 33 | 0 | 2 | 0 | 0 | 1 |
[23] † Proxenocrinus inyoensis Last Modified in 10/03/23 | 4 | 32 | 32 | 0 | 3 | 0 | 0 | 1 |
[24] † Glenocrinus globularis Last Modified in 10/03/23 | 5 | 32 | 32 | 0 | 2 | 0 | 0 | 1 |
[25] † Titanocrinus sumralli Last Modified in 10/03/23 | 1 | 36 | 36 | 0 | 2 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 2415 | |
Project overview | 104 | |
Matrix views | 93 | Matrix landing page (84 views); Guensberg et al 2020 (9 views); |
Media views | 688 | Media search (277 views); M894663 (49 views); M894664 (56 views); M894665 (51 views); M894666 (52 views); M894667 (50 views); M894668 (50 views); M894669 (51 views); M894670 (52 views); |
Documents list | 85 | |
Bibliography | 64 | |
Views for media list | 101 | |
Specimen list | 618 | |
Taxon list | 662 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 1 | |
Matrix downloads | 1 | Guensberg et al 2020 (1 download); |