Judith Masters and Fabien Génin: An unwavering union in strepsirrhine evolution.

This preamble honors the late evolutionary primatologists Judith Masters and Fabien Génin, synthesizing their profound impact on strepsirrhine anatomy, systematics, and biogeography. Over four decades, Masters applied Hugh Paterson's Recognition Concept of species alongside comprehensive craniodental morphometrics and phylogenetics to reframe the evolutionary trees of nocturnal African galagos, culminating in the formal description of the dwarf galago genus Paragalago. Génin complemented this systematic framework by linking sensory ecology with comparative physiology, providing groundbreaking evidence of energetic plasticity-such as facultative heterothermy and torpor-in Malagasy mouse lemurs. Together, their collaborative research challenged major primatological paradigms by refuting the "primitive" status of cheirogaleids and critiquing standard socio-ecological models in favor of species-recognition frameworks driven by sensory drive. Furthermore, their interdisciplinary work proposed an alternative view of vertebrate colonization of Madagascar. Beyond their empirical contributions, they established the African Primate Initiative for Ecology and Speciation (APIES) and the Primate Ecology and Genetics Group (PEGG), leaving a lasting legacy of regional capacity-building and postgraduate mentorship that reshaped southern African primatology.