Riverine flow rate drives widespread convergence in the shell morphology of imperiled freshwater mussels

Frequent and strong morphological convergence suggests that determinism tends to supercede historical contingencies in evolutionary radiations. For many lineages living within the water-column of rivers and streams, hydrodynamic forces drive widespread morphological convergence. Living below the sediment-water interface may release organisms from these hydrodynamic pressures, permitting a broad array of morphologies and thus less convergence. However, here, we show that the semi-infaunal freshwater mussels have environmentally determined convergence in shell morphology. Using 3D morphometric data from 715 individuals among 164 Nearctic species, we find that species occurring in rivers with high flow rates have evolved traits that resist dislodgement from their burrowed position in the streambed: thicker shells for their body size, with the thickest sector of the shell being the most deeply buried. Species occurring in low-flow environments have evolved thinner and more uniformly thicken..., , , # Riverine flow rate drives widespread convergence in the shell morphology of imperiled freshwater mussels

[https://doi.org/10.5061/dryad.dbrv15f75](https://doi.org/10.5061/dryad.dbrv15f75)

## \#\#\# data\.zip

Compressed data directory with the following files and folders:

## \#\#\#\# data/dataset\_Keogh\_etal\_amblemine\.xlsx

\- Spreadsheet with 4 sheets:
1\. field\_codes: definitions of fields in subsequent sheets\.
2\. all\_meshes: the specimens used in this study with taxonomic\, habitat use\, georeferencing\, museum\, and scanning information\.
3\. species\_traits: Aggregated species habitat use traits and phylogenetic tip names\.
4\. phylogeny; in newick format

## \#\#\# data/mesh/

\- 3D mesh files \(\.ply format\) for specimens used in the study\. Includes mesh surfaces cut into interior \(INT\) and exterior \(EXT\) surfaces\.
\- 3D surface mesh files for specimens used in the study are in binary \"Polygon File Format\" or \"\`\.ply\` format\.\" Binary ply files can be opened ...