The terracotta animals and fish which decorate the Mineral Gallery were thought to be extinct at the time Waterhouse designed them. These include the tapir-like palaeotherium and shelled ammonites peeking out of foliage at the tops of the columns, with fish swimming through the rippling water below.
The coelacanth, featured on some of the terracotta columns here and pictured above, is a major exception. Coelacanths were found swimming off the coast of South Africa in 1938, 80 million years after their presumed date of extinction. A specimen of the coelacanth, first known to be living 380 million years ago, is on display in one of the archways in Hintze Hall (formerly the Central Hall).