Testing the applicability of automated size and shape analyses in non-marine ostracods-A case study from the Tibetan Plateau

Evolutionary developmental biology seeks to elucidate the developmental mechanisms underlying phenotypic evolution. Central to this endeavour is the quantitative analysis of morphological variation, for which morphometric approaches have become indispensable tools across micropaleontology.

The suitability of ostracods (bivalved microcrustaceans) for evolutionary, developmental, and paleoecological investigations stems from several key attributes: near-ubiquitous distribution across marine and freshwater habitats, remarkable taxonomic and morphological diversity, sensitivity to environmental parameters, and an exceptional fossil record with calcified carapace valves that preserve fine morphological details across geological time scales. These characteristics make ostracods powerful proxies for paleoenvironmental reconstruction and biostratigraphy. While morphometric methods are widely applied to other microfossil groups, their use in ostracods remains comparatively limited, largely because the labor-intensive nature of manual data acquisition constrains dataset size, scalability, and reproducibility despite their considerable potential.

To address this bottleneck, we evaluate the efficacy of AutoMorph (Hsiang et al. 2016), a high-throughput imaging pipeline, for automated extraction of size and shape data from ostracod valves. We apply this approach to two lacustrine ostracod species, Leucocythere dorsotuberosa and Leucocytherella sinensis, sampled from four lakes across the Tibetan Plateau—a region offering both exceptional ecological diversity and significant paleoclimatic archives.

Our findings demonstrate that AutoMorph successfully extracts morphometric measurements and coordinate data from ostracod valves, reducing processing time by approximately 90% compared to traditional manual methods while minimizing subjective bias inherent in landmark placement.

This methodological advancement facilitates the generation of large-scale spatial and temporal datasets from both modern and fossil assemblages, which enables more comprehensive investigations of ecological responses to environmental change and evolutionary processes. The utilization of tools like AutoMorph can, thus, fundamentally expand existing micropaleontological methodologies, enabling robust, high-throughput quantitative analyses and opening new avenues for comparative and integrative research not only for ostracods.