Upon observing the lower jawbone of a horse at the side of a road he was travelling, Linnaeus remarked: "If I only knew how many teeth and of what kind every animal had, how many teats and where they were placed, I should perhaps be able to work out a perfectly natural system for the arrangement of all quadrupeds."
Despois de observar a mandíbula inferior dun cabalo na beira dunha estrada pola que estaba a viaxar, Linné comentou: "Se tan só coñecese cantos dentes e de que tipo ten cada tipo de tódolos animais, cantas mamilas e onde están situadas, quizais podería facer un sistema natural perfecto para a organización de tódolos cuadrúpedes."