Patterns in schizomid flagellum shape from elliptical Fourier analysis

Area of Science:

• Arachnology
• Evolutionary Biology
• Morphometrics

Background:

• Schizomida, an understudied arachnid order, inhabits soil globally.
• Male flagella exhibit diverse shapes crucial for taxonomy and courtship.

Purpose of the Study:

• Quantify male flagellum shape diversity in Schizomida.
• Analyze shape variation across taxonomic and biogeographic categories.
• Investigate evolutionary allometry and shape clustering.

Main Methods:

• Elliptical Fourier analysis applied to nearly 550 dorsal and lateral flagellum outlines.
• Categorization by genus, family, biogeographic realm, and habitat (focus on Caribbean/Cuba).
• Statistical tests for allometry, disparity, and morphospace clusters.

Main Results:

• Significant flagellum shape differences identified across genera, families, and biogeographic realms.
• Evidence of evolutionary allometry and discrete shape clusters in morphospace.
• Overlapping morphospace does not negate distinct shape variations.

Conclusions:

• Male flagellum shape is a valuable taxonomic character in Schizomida.
• Shape diversity reflects evolutionary processes and biogeographic history.
• This study provides a foundation for future research on Schizomida evolution and diversification.