Anatomy of a polyp (Source: NOAA) Coral biology Corals are invertebrate animals belonging to a large group of colourful and fascinating animals called Cnidaria. Other animals in this group that you may have seen in rock pools or on the beach include jelly fish and sea anemones. Although Cnidarians exhibit a wide variety of colours, shapes and sizes, they all share the same distinguishing ...
It appears that you have stumbled upon some pretty interesting marine fossils. 2 appears to be a rugose coral and 3 appears to be a series of internal molds of rugose coral calices. For 3, imagine that sediment filled the hollow area of your second specimen, hardened into rock, and later the original coral dissolved away.
The recently released report, Coral Reefs of the Gulf of Mannar, Tamil Nadu, India: Decadal Changes in Status and Management Paradigms, by ICRI Member, Suganthi Devadason Marine Research Institute (SDMRI), and the Tamil Nadu government, provides an in-depth analysis of two decades of changes in the Gulf of Mannar’s coral reefs. This region, recognized for its ecological and economic ...
Coral reefs of the Gulf of Mannar, Tamil Nadu, India - Decadal changes ...
So, I bought a book called The Rugose Coral Genera by Geoffrey Cotton (1973) and it does an excellent job of giving a short description of what looks like thousands of different rugose corals (both colonial and solitary). Here is my original list of five filled out and corrected with information from the book. Let me know if you want to know what it says about any others. I don't mind copying ...