From the bone marrow-derived mouse osteochondral SSCs, the lineage-committed bone, cartilage, and stromal precursor (BCSP) cell gives rise to osteoblasts, chondrocytes, and stromal cells, but not bone marrow adipose. Human perivascular SSCs give rise to bone marrow adipose and under specific circumstances, e.g., fracture—bone, cartilage, and stroma. Aging skews lineage output (indicated by arrows). Surface markers identify skeletal cell types in mice [19,25]. *Chondrocyte generation persists throughout life, however clonal diversity of chondral tissues and generation of articular chondrocytes significantly diminishes with age, while injury-activated SSCs give rise to hypertrophic chondrocytes that generate mostly fibrocartilage [30].