1997/08/01 by Simon J. Braddy, Jason A. Dunlop · 36 citations
Biochemistry, Genetics and Molecular Biology · Environmental Science · Earth and Planetary Sciences · #Spider Taxonomy and Behavior Studies #Amphibian and Reptile Biology #Subterranean biodiversity and taxonomy #Biology #Spermatheca #Spermatophore #Appendage #Anatomy #Mating #Zoology #Operculum (bryozoa) #Sex organ #Sperm #Botany
paper · doi:10.1111/j.1096-3642.1997.tb01282.x
published in Zoological Journal of the Linnean Society 120(4), 435-461 (Oxford University Press)
openalex publication_date 1997/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The functional morphology of the genital appendages, horn organs and modified prosomal limb III of the Silurian eurypterid, Baltoeurypterus tetragonophthalmus (Fischer, 1839) (Chelicerata: Eurypterida) is investigated. The longer type A genital appendage, interpreted as a female structure, is associated with a pair of horn organs, regarded as spermathecae. The shorter type B appendage, interpreted as male, is associated with scimitar lobes on prosomal limb III, regarded as clasping structures. A mechanism is proposed by which the type A appendage was lowered through flexure of the genital operculum acting along sutures in the cuticle. A model of mating is suggested, involving the male depositing an unstalked spermatophore on the substrate and the female retrieving it for storage in the spermathecae. This model is more arachnid-like than mating in Limutus (an extant aquatic chclicerate), and suggests that sperm transfer using spermatophores and storage of sperm in spermathecae, allowed the timing of egg production in eurypterids to be controlled.