Structure genealogy

Each structure occupies one row, placed at every year a paper reported it; rows are ordered by first appearance (oldest at the bottom). Dot colour marks the object's role, ordered by the year that role first entered the map — so warmer rows arrived later. Dot size = papers that year; a star marks a structure reported by at least two papers that share no author — computed, not hand-assigned. The panel below stacks the same reports into activity per role per year.

This is not a claim that one structure was literally derived from another — the schema doesn't encode structure-to-structure lineage. It shows when each shape entered the literature, how sustained the attention was, and how the mix of mathematical roles shifted over time.

Not yet dated (no paper in data/papers/ lists them) — 1 structure: 2D Grid (Square Lattice).