This interactive tree diagram displays the animal taxonomy hierarchy from a root down through kingdoms, classes, orders, and species. It uses d3.stratify to convert a flat parent-child dataset into a hierarchy and d3.tree to compute the layout, then renders nodes and links as SVG elements. Each depth level is color-coded via CSS classes, and node circles are clickable with a tooltip. The example shows a color legend for depth layers and relies on d3.v7 for all data binding and layout operations.