A novel bright-yellow pigmented bacterial strain SM2-F^T was isolated from a mangrove sediment collected at the mangrove coast of Luoyang estuary, Quanzhou, China. Strain SM2-F^T was Gram-stain-negative, catalase-weak positive, oxidase-positive, rod-shaped, non-flagellated and non-motile. Growth of strain SM2-F^T was observed at 20–40 °C (optimum, 30 °C), pH 6.0–8.0 (optimum, pH 7.0) and in the presence of 1.0–4.0% NaCl (optimum, 2.0% NaCl). Flexirubin-pigment was absent, and carotenoid-pigment was present. Phylogenetic analysis of 16S rRNA gene sequence placed strain SM2-F^T into the family Flavobacteriaceae and shared the maximum sequence similarity with Aequorivita soesokkakensis RSSK-12 ^T of 92.5%. Whole genomic comparison between strain SM2-F^T and close relatives suggested a novel species of a novel genus. The predominant quinone of strain SM2-F^T was menaquinone (MK)-6. The major fatty acids (> 10%) comprised iso-C_15:1 G (32.4%) and iso-C_15:0 (29.1%). The polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminolipids and four unidentified lipids. The complete genome size was 4,094,245 bp with DNA G + C content of 36.0 mol%. Based on the data of polyphasic study, strain SM2-F^T was considered to represent a novel species of a novel genus, for which the name Aegicerativicinus sediminis gen. nov., sp. nov., was proposed. The type strain was SM2-F^T (= MCCC 1K04383^T = KCTC 82361 ^T).