Hypnovenator matsubaraetoheorum was named by Kubota et al. (2024) [Kubota et al. (2024): on Holotype: "MNHAH D1033340, consisting of two caudal vertebrae, two dorsal ribs, thirty-eight gastralia, a chevron, left humerus, left radius, left ulna, left carpal, left metacarpals I to III, the distal end of right metacarpal I, left manual phalanges I-1, I-2, II-1, II-3, and III-1 to 4, the distal part of left femur, left tibia and fibula missing the mid-shaft, the distal end of right tibia, left astragalus, the distal end of right astragalus, the proximal parts of left metatarsals II to V, the proximal ends of right metatarsals II and IV, right pedal phalanges II-3, III-1 to 4, and IV-1 to 5 (Figs. 2, 3; Supplementary Figs. S1–S13 and Table S1)."]. Its type specimen is MNHAH D1033340, a partial skeleton, and it is a 3D body fossil. Its type locality is Nishikosa, which is in an Albian/Albian fluvial sandstone in the Ohyamashimo Formation of Japan. It is the type species of Hypnovenator.