The Guardian has an article on the greatest discoveries in zoology:
At BBC Wildlife magazine, a panel of judges has been mulling over the question. Today, the results of their deliberations are published as the top 10 breakthroughs in zoology. The list in full is below, in descending order. How have they fared?
Leeuwenhoek places second, just below the discovery of the fossilised remains of Archaeopteryx:
The 17th century Dutch scientist Antonie Philips van Leeuwenhoek made some of the best microscopes of his time, using them to discover microorganisms, or “animalcules”. His work led to dramatic re-evaluations of the causes of disease and improvements in hygiene.