Linkages between hatchling and adult sauropods concerning morphological and ontogenetic growth remain enigmatic, which is even more tenuous in early sauropods. However, discoveries from Southeast Asia could provide significant insights into these questions of developmental history with the recent discovery of a partial juvenile vertebral series from an early sauropod from the early Middle Jurassic Nam Phong Formation, Chaiyaphum province, northeastern Thailand. Here we present the anatomical description of preserved portions of the axial skeleton, including cervical and dorsal vertebrae. Our study demonstrates the presence of 1) incipient laminae and fossae on the centrum; 2) unfused neural arch (cervical and dorsal); and 3) well-marked vertebral lamination system, all of which are osteological hallmarks of an immature growth phase. Particularly, we note that in this hatchling-juvenile specimen, the vertebral lamination complex resembles an adult early sauropod's form, along with no true pleurocoel in the vertebral arches. The co-occurrence of these two characters would strongly indicate a non-eusauropod sauropod affinity. With the presence of the lamination pattern, and the temporal placement of the specimen in the early Middle Jurassic, our material mostly resembles the Tazoudasaurus, so we assign the material to the Vulcanodontidae. Further analysis of this hatchling-juvenile specimen will provide crucial insights into the ontogenetic developmental history and musculoskeletal function, successfully filling a current knowledge gap within early sauropods evolutionary studies.