This interactive phylogenetic tree visualizes the hierarchical relationships within the placental mammal family tree. Branching from a central Placentalia root, nodes represent taxonomic orders, with each level distinguished by a unique color applied to text, circles, and connecting paths. The D3.js v5 code constructs a tree layout using d3.tree, d3.hierarchy, and d3.linkHorizontal, while d3.json loads the embedded data. Node circles scale relative to a fixed value, and labels use Playfair Display font, drawing from a 2017 Scientific American article.