1. Their spacing is regular, a telltale mark that the flow field around each sea pen defines the optimum spacing of neighbors.

2. ‘The oldest Anthozoans are probably some of the polyp-like and sea pen-like fossils from the Vendian (late Precambrian).’ ‘In addition to their relevance as model organisms for understanding metazoan evolution, Anthozoans are ecologically important.’

3. Chaetodon capistratus is a browser who feeds on Anthozoans preferring hexacoral such as scleractinians, anemones, and zoantharians.: Most symbiotic Anthozoans live in nutrient-poor tropical waters.: The oldest Anthozoans are probably some of the polyp-like and sea pen-like fossils from the Vendian.: Anthozoans are readily available on coral reefs therefore it's not surprising that Anthozoan