Phenotypic macroevolutionary studies provide insight into how ecological
processes shape biodiversity. However, the complexity of phenotype-ecology
relationships underscores the importance of also validating
phenotype-based ecological inference with direct evidence of resource use.
Unfortunately, macroevolutionary scale ecological studies are often
hindered by the challenges of acquiring taxonomically and spatially
representative ecological data for large and widely distributed clades.
The South American cichlid fish tribe Geophagini represents a
continentally distributed radiation whose early locomotor morphological
divergence suggests habitat as one ecological correlate of
diversification, but an association between locomotor traits and habitat
preference has not been corroborated. Field notes accumulated over decades
of collecting across South America provide first-hand environmental
records that can be mined for habitat data in support of macroevolutionary
ecological research. In this study, we applied a newly developed method to
transform descriptive field note information into quantitative habitat
data, and used it to assess habitat preference and its relationship to
locomotor morphology in Geophagini. Field note-derived data shed light on
geophagine habitat use patterns and reinforced habitat as an ecological
correlate of locomotor morphological diversity. Our work emphasizes the
rich data potential of museum collections, including often overlooked
material such as field notes, for evolutionary and ecological research.