Acervularia pentagona explained

Acervularia pentagona is an extinct species of tabulate coral. It is described as the smallest Acervularia species known, and most closely resembles A. coronata.^[1]

Notes and References

1. Book: Milne-Edwards. H.. A Monograph of the British Fossil Corals. Haime. Jules. 2015-03-05. Cambridge University Press. 978-1-108-08088-0. en.