Data from: Elucidating the morphology and ecology of Eoandromeda octobrachiata from the Ediacaran of South Australia
Data files
Nov 14, 2023 version files 260.32 KB
Abstract
Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral-octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda. Here we use the novel application of rotational geometric morphometrics together with palaeoenvironmental information to provide a better insight into their palaeobiology and ecology and to address conflicting hypotheses regarding mode of life and taxonomic affinity. We find that Eoandromeda likely had a radially symmetrical shape in life, was cone-shaped and had a high relief off the microbial mat. Analysis of the symmetric and asymmetric shape components revealed they deform strongly in the direction of palaeocurrent, therefore are thought to be made of a flexible material. Almost all specimens are compressed flat. Specimens that appear to have not fully collapsed support the idea that Eoandromeda was likely cone-shaped and further suggest that they possibly collapsed spirally. Our shape analysis along with observed morphological features support the benthic mode of life hypothesis rather than pelagic. Morphological and ecological inconsistencies do not fully support the hypothesis of a Ctenophora taxonomic affinity.
README: Elucidating the morphology and ecology of Eoandromeda octobrachiata from the Ediacaran of South Australia
Tory L. Botha: Principal investigator, University of Adelaide, ORCiD: 0000-0002-2519-9365
Description of files and data:
coEo:
Text file dictating how the landmarks are rotated and relabeled
SymmetryFunctions:
R Function written by Savriama (Frontier in Plant Science, 2018) that rotates and relabels the specimens
R code:
R Code for analysis of Eoandromeda
Collections_7armlmk:
* .tps file containing the standardised landmarks for collection specimens that were landmarked
* Three columns present in the files representing X, Y, Z coordinates of the landmarks
Eo + Float_7armlmk:
* .tps file containing the standardised landmarks for LV-Eo Bed + Float specimens that were landmarked
* Three columns present in the files representing X, Y, Z coordinates of the landmarks
Parv Bed_7armlmk:
* .tps file containing the standardised landmarks for WS-Parv Bed specimens that were landmarked
* Three columns present in the files representing X, Y, Z coordinates of the landmarks
Sub Bed_7armlmk:
* .tps file containing the standardised landmarks for WS-Parv Bed specimens that were landmarked
* Three columns present in the files representing X, Y, Z coordinates of the landmarks
Arms.csv:
raw measurements (in mm) of average arm width, average arm length and centroid size per specimen (centroid size was calculated from landmarked specimens during the generalised Procrustes analysis (GPA))
| For Arms.csv file - <br>Specimens beginning with: | |
|---|---|
| P | <ul><li>from the South Australian Museum (SAMA) collections</li></ul> |
| Eo Bed | <ul><li>from LV-Eo Bed</li></ul> |
| Parv Bed | <ul><li>from WS-Parv Bed</li></ul> |
| Sub Bed | <ul><li>from WS-Sub Bed</li></ul> |
| L | <ul><li>from Lower float section associated with LV-Eo Bed</li></ul> |
| M | <ul><li> from Middle float section associated with LV-Eo Bed</li></ul> |
| U | <ul><li>from Upper float section associated with LV-Eo Bed</li></ul> |
8 of the collection’s scans were analysed within the LV-Eo bed + Float dataset as this was a float piece found associated with the bed and brought back to SAMA previously.
- P55445
- P55446
- P55447
- P55449
- P55451
- P55452
- P55457
- P55458
Methods
Three-dimensional (3D) surfaces of these specimens were captured using the HDI Compact C506 and 3Shape TROIS 4 Intraoral 3D laser scanners (accuracies reported to 12µm and c.5µm respectively). Scans were prepared using the FlexScan3D and TRIOS Design Studio software (correspondingly) and processed (landmarked/measured) in the MeshLab software (Cignoni et al. 2008).
Usage notes
R and excel required to view and process the files.