Reptiles unique to Senegal include the Gabou File Snake Mehelya gabouensis (Google Books) and the Senegal Worm Lizard Cynisca senegalensis (p. 65 of AMNH Digital Library 19 MB pdf file). The skink Trachylepis breviparietalis (Internet Archive) known from a single specimen is considered a synonym of Trachylepis perrotetii (p. 29 of BzB pdf file).
A freshwater fish known solely from Senegal is the recently described catfish Auchenoglanis senegali (PlanetCatfish).
Marine fishes exclusive to Senegal include a blenny Malacoctenus africanus
and two snake eels known only from single specimens: Dalophis multidentatus (p. 73 of IRD pdf file)
Insects found only in Senegal include a plant bug Dominiquella vitellina (AMNH), a vivid metallic ground beetle Chlaenius oligochrysus (Carabidae of the World), a dung beetle Onthophagus quiproquo (Association Troglorites), a longhorned beetle Phyllocnema jeanneli (Association Troglorites), a skin beetle Ctesias dakariensis (naturkundemuseum-bw.de pdf file), the ants Monomorium dakarense (AntWiki) and Tetraponera claveaui (AntWiki), a bee Meliturgula senegaliae (Discover Life), a cuckoo wasp Chrysis senegalana (p. 12 of BioNames pdf file), a butterfly Lycaena (or Chilades) serrula (BHL), and a damselfly Elattoneura pluotae (IUCN).
Endemic arachnids include a pholcid spider Pholcus berlandi (Internet Archive) and a jumping spider Rhene sulfurea (Jumping Spiders). Potamonautes senegalensis
(p. 19 of AToL
Decapoda pdf file) is an endemic freshwater crab. Endemic
marine invertebrates include a sponge Axinyssa djiferi (MDPI), a nudibranch Berghia marinae (p. 11 of ResearchGate), and several cone snails including Conus pineaui (Eddie
Hardy), Conus unifasciatus (ARKive), Conus
Biodiversity), Conus echinophilus (IUCN), Conus hybridus (ARKive), and Conus mercator (IUCN).
Vascular plants restricted to Senegal (p. 83 of USAID pdf file) include Abutilon macropodum (JSTOR), Digitaria (or Paspalum) gentilis (MNHN), Eriocaulon inundatum (JSTOR), Ilysanthes congesta (JSTOR), Oldenlandia parva (JSTOR), Pandanus columellatus (JSTOR), Panicum calocarpum (JSTOR), Scirpus (or Hibiscus hasirikus (JSTOR), and Scleria chevalieri (JSTOR).
Terrestrial ecoregions in Senegal include the West Sudanian Savanna (WWF), the Sahelian Acacia Savanna (WWF), and the Guinean Forest-savanna Mosaic (Wikipedia). For an overview of the biota see the "Senegal Biodiversity and Tropical Forests Assessment" (USAID pdf file).