96 - Cidaris

Hello friends, Welcome to the Fossil Repository at the Department of Geology, Shivaji Science College, Nagpur. I am Cidaris. I am a fossil. My spherical test skeleton is composed of tightly interlocking plates, giving me a rigid and protective structure. One of the most distinctive features about me is my long, stout spines extending from my test, providing defence against predators. These spines are often covered in small, sharp tubercles. I have five double rows of tube feet called ambulacra, running along my test between the interlocking plates. These tube feet are my means of locomotion, feeding, and sensory perception. The base of my test is typically flattened, forming a sturdy pedestal that allows me to rest securely on the substrate. My small mouth is located on the underside of my test, surrounded by a complex feeding structure known as Aristotle's lantern. This structure consists of five tooth-like plates used for scraping algae and other food from surfaces. My coloration can vary depending on my species and habitat, ranging from shades of brown and red to purple or green. I am typically found in shallow to moderately deep waters, often on rocky substrates or among seagrass beds. Like other sea urchins, I play important roles in marine ecosystems as a grazer, feeding on algae and other organic material, and as prey for various predators. I reproduce sexually, with males releasing sperm and females releasing eggs into the water for external fertilization. Our larvae undergo a planktonic phase before settling and developing into juveniles. Fossil cidaroids like me have been found dating back to the Jurassic period, and we have a long evolutionary history dating back hundreds of millions of years. Thank you for visiting.