Lizards are the closest relatives of humans able to suppress fibrosis and regrow multiple tissue lineages following appendage regeneration. As amniotes capable of tail, but not limb regrowth, lizards are also distinguished as the only vertebrate group that include both regenerative and non-regenerative appendages in the same animal. Lizard tail stumps naturally form blastemas - heterogenous collections of fibroblasts, adult stem cells, and immune cells that suppress scar formation and potentiate new tissue growth. Conversely, amputated lizard limbs form scars similar to those observed in human patients. Lizard blastema formation is dependent upon tail spinal cord tissue, which contains distinct populations of radial glia and microglia. Using the parthenogenetic lizard