Data From: Palaeoecology of Middle Devonian epizoans and their Paraspirifer hosts
Data files
Mar 19, 2026 version files 174.12 KB
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Data1MeasurementData.csv
6.10 KB
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Data2EpibiontLocationData.csv
122.64 KB
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Data3ProcrustesAndPC.csv
41.63 KB
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README.md
3.76 KB
Abstract
The Silica Shale brachiopod, Paraspirifer bownockeri, of Ohio and Michigan, USA preserve a unique window into Middle Devonian communities, as they hosted numerous epibionts. Herein, we use qualitative and quantitative methods to test hypotheses regarding the palaeoecology of these brachiopod hosts and their epibionts. We analysed the number and type of epibionts on the dorsal valve, ventral valve, hinge, and commissure of over 200 specimens. Using a variety of statistical techniques, we tested hypotheses regarding the relationships of these epibionts both to their host and to one another. We also produced 3D models of these specimens to explore hypotheses as to how epibiont colonization impacted host morphology. Finally, we compare our results to previous work on Silica Shale brachiopods. Our data show a correlation between shell morphology and epibiont placement that may indicate preferential placement in the water column or epibiont influence on host morphology. We found an average of 1.96 epibionts per host, with several significant correlations between co-occurring pairs. By applying this new data to previously published life position models and epibiont placement data, we reevaluated the life position of these brachiopods and found that the most likely position these brachiopods would have been found in life would have been with the commissure 30–45˙ angled above the sea floor. Our interpretation of the results differs from original work on these brachiopods with regards to the epibiont relationships to one another, colonization patterns, and life position but supports more recent work evaluating spirifer life position and morphology.
Dataset DOI: 10.5061/dryad.rxwdbrvq1
Description of the data and file structure
These data were collected from specimens at the University of Michigan Museum of Paleontology. Measurement data and epibiont location and identification data were collected on specimens of Paraspirifer bownockeri.
Files and variables
Data1MeasurementData.csv
This .csv file includes the raw measurement data used to test if size bins were needed for specimen analysis (supplementary Figure 2). All measurements are reported in centimeters. Metrics measured in ImageJ are illustrated in Fig. 2.
The following information is included:
- UMMP Catalog Number: Specimen number from the University of Michigan Museum of Paleontology catalog
- Hinge Line Width: Width as measured across the hinge axis of the brachiopod.
- Length: Measured from the beak to commissure across the axis of symmetry.
- Maximum Width: Measured parallel to the hinge axis.
- Height: Measured from the apex of the fold to the bottom of the ventral valve, when viewed from the commissure.
Data2EpibiontLocationData.csv
This .csv file includes the raw location data of each epibiont location, used to create Data 3-4, Supplementary Figures 1, 3, and 4, and Figures 4–10. The methods used to describe relative epibiont location may result in an overrepresentation of epibiont abundance if not read as presence/absence per location, as single epibionts can cover multiple of the measured locations (e.g., a single encruster may cover a portion of both the fold and the right side of the dorsal valve). Each individual instance (as distinguishable) is marked by a 1 in the respective location of the epibiont, to allow conversion to presence/absence data. Missing values indicated by blank cells.
The following information is included:
- UMMP IP #: Specimen number from the University of Michigan Museum of Paleontology catalog.
- Specimen Identification: Brachiopod identification, in this case all, Paraspirifer bownockeri.
- Encrusting material: Identification of encrusting epibiont to the highest degree of certainty.
- Encrusted Location: Location of the encruster identified in the previous column, denoted here in shorthand PD (Pedicle, or ventral valve) and BV (Brachial, or dorsal valve).
- PD (Left, Middle, Right): Relative position of the encrusting material on the ventral valve, with the hinge line oriented “up” and “middle” meaning within the sulcus. The value in “PD” is the total number of individual epibiont occurrences on the ventral valve.
- BV (Left, Middle, Right): Relative position of the encrusting material on the dorsal valve, with the hinge line oriented “up” and “middle” meaning within the fold. The value in “BV” is the total number of individual epibiont occurrences on the dorsal valve.
- F: Fold
- S: Sulcus
- HC: Hinge Line
- C: Commissure
- Notes: Additional notes on placement, identification, over-encrustation, or other notable features of the specimen.
Data3ProcrustesAndPC.csv
This .csv file compiles the Procrustes and pc data from the 54 specimens that were 3D modeled and used for morphometric analysis. This data correlates to Supplementary Figure 4 and Figures 7–9. All corresponding 3D data are available on https://umorf.ummp.lsa.umich.edu/wp/
Access information
Other publicly accessible locations of the data:
- 3D model data referenced in Fig. 3, Fig. 7, Fig. 8, Fig. 9, and Supplementary Figure 4, and Data 4 is available on https://umorf.ummp.lsa.umich.edu/wp/