Fossils exemplifying Hamilton’s handwritten numbers. A. 2-digit number (“16”) written in pencil, plus identification (“Duck); right tarsometatarsus of an Anatidae bird, NMNZ S.54262. B. 2-digit number (“44”) written in pencil; right tarsometatarsus of a Phalacrocoracidae bird, NMNZ S.53956. C. 2-digit number (“32”) written in ink, plus the NMNZ number written during the present study; left carpometacarpus of a songbird (Passeriformes), NMNZ S.55301. D. 2-digit number (“75”) written in ink; left tarsometatarsus of a Diomedeidae bird, NMNZ S.54355. Scale bar: 2 cm.