With regard to the article by Damian Carrington (‘Technofossils’: how humanity’s eternal testament will be plastic bags, cheap clothes and chicken bones, 22 February), the geologists Sarah Gabbott and Jan Zalasiewicz are right to point to the extraordinary stratigraphic legacy of technofossils like plastics, textiles and concrete, and associated biological matter such as the billions of factory-farmed chicken bones in landfill.
But they are wrong to link the increasing size and abundance of chicken bones in strata with a precisely defined “start” of the Anthropocene. As with plastics and concrete, the signal of chicken bones, while clearly an intensifying one, is manifestly spread out through time and space, and cannot be pinned down to a single date.
