This interactive visualization shows a hierarchical animal classification tree, mapping the relationships between major taxonomic groups from the root "Animals" down to specific classes like Mammals, Birds, and Insects. The layout uses colored node strokes and level-based colors to distinguish parent categories from leaf nodes. Built with React and D3.js version 3.5, the diagram uses the `d3.layout.tree` function and SVG diagonal paths to draw curved links, with smooth animated transitions when nodes update or expand. The tree data is embedded directly in the code as a JSON array.