👉 The term "diplacanthidae" refers to a group of extinct marine and terrestrial animals that lived during the Late Cretaceous period, approximately 69 million years ago. These animals were part of a large family called Diplacanthidae, which also includes other extinct marine and terrestrial animals such as the Hymenoptera, Antennophyta, and Pteropoda. The name "diplacanthidae" is derived from "dipl
