The dry semi-desert that is South Africa’s Karoo began as an ice cap on the supercontinent Pangea, when Euramerica and Gondwana were joined into one large land mass. The Karoo ice cap was kilometers deep and peaked between 359 and 299 million years ago. Planetary temperatures dropped in that period, since the evolution of land plants elsewhere on the planet took up so much CO2 that earth lost its greenhouse roof. 1 Many paleontologists think it was an early form of termites that ended...