The dung beetle genus Scarabaeus (Coleoptera, Scarabaeinae, Scarabaeini), predominantly found in the arid regions of the Old World, includes three endemic species inhabiting the dry ecosystems of western and southern Madagascar. These species are presumed to form a monophyletic clade nested within the African Scarabaeus. Semantic modelling of phenotypes using ontologies represents a transformative approach to species description in biology, making phenotypic data FAIR and computable. The recently developed Phenoscript language enables the creation of semantic, computable species descriptions using a syntax akin to human natural language (NL). However, Phenoscript has not yet been tested as a tool for describing new taxa. In this study, we test the utility of Phenoscript by describing a new species, Scarabaeus (sensu lato) sakalava sp. nov. from Madagascar. The initial description is composed directly in Phenoscript, replacing the traditional natural language format. This Phenoscript description is then translated into a human-readable form using the Phenospy tool for publication purposes. Additionally, the Phenoscript description is converted into an RDF graph, making it understandable by computers using semantic technologies. Scarabaeus sakalava sp. nov. is found in western central Madagascar and is closely related to S. viettei (Paulian, 1953) from north-western Madagascar. We provide an updated identification key and distribution map for all Malagasy Scarabaeus and discuss their systematic placement.