This paper reports the first discovery of a stegodont from Sishui, Shandong, represented by a partial maxilla preserving associated left and right M2–M3 series. The specimen is characterized by the following features: in ventral view, the upper jaw is relatively narrow with the left and right tooth rows converging anteriorly; the M3 crown possesses 8 ridges/lophs; the anterior ridges, upon wear, reveal a faint median sulcus and remnants of the central conule; and the enamel layer is well-folded. The ridge morphology and conelet arrangement pattern conform to the typical characteristics of the genus Stegodon. Based on the presence of 8 ridges on the M3, its large body size, and a notably higher ridge count compared to its direct ancestor, Stegodon zdanskyi (M3 typically with 6–7 ridges), while falling within the known range of variation of Stegodon chiai (M3 with 8–9 ridges), this specimen is referred to Stegodon chiai Chow & Zhai, 1962. Its geological age is likely Early Pleistocene or Late Pliocene. This specimen represents the first discovery of an upper jaw of Stegodon chiai and the first record of stegodont fossils in Shandong Province, providing important new evidence for the morphology, geographic distribution, and evolutionary relationships of this species in East and South Asia. It also provides important support for the reconstruction of paleogeography and paleoclimate.

报道了在山东泗水首次发现的一件大型剑齿象上颌化石，并附有左右M2与M3颊齿。该标本具有以下关键形态特征：上颌腹视相对狭窄，左右齿列在前方靠近；M3齿冠具8个齿脊，前部齿脊磨耗后显示出微弱的中沟及中心小尖残留，釉质层褶皱发育；齿脊形态与乳突排列模式符合剑齿象属典型特征。基于其M3具8个齿脊、体型宏大，且齿脊数显著多于其直接祖先——师氏剑齿象(Stegodon zdanskyi, M3通常具6–7脊), 而与贾氏剑齿象(Stegodon chiai)已知的齿脊数变异范围(M3具8–9脊)一致，因此将标本归入贾氏剑齿象(Stegodon chiai Chow & Zhai, 1962)。其地质时代可能为早更新世或晚上新世。这是贾氏剑齿象上颌骨的首次发现，也是山东地区剑齿象化石的首次记录，为该种的形态解剖、地理分布及与东亚和南亚的相关类群的对比，以及古地理和古气候的重建提供了重要的新材料。