The oldest echinoids are around 450 million years old, from the Ordovician period of the Paleozoic Era which was 220 million years before dinosaurs started appearing. Echinoids still exist today and continue to diversify living among shallow coastal waters across the world. The roots of modern sea urchins can be traced back around 250 million years ago to the Permian period of the Paleozoic Era. The animal consisted of a hard shell, referred to as a test, with spines protruding out from the small knobs, known as tubercles. The primary function of the test was to protect and support the soft body with the spines protecting against predators. Rarely the spines and tests are fossilised together, it is common to find fossilised spines broken away from the knobs.
Pair of Echinoid Fossils
A fine example of an echinoid, sea urchin, fossil. It is distinguishable as part of the Clypeus Ploti genus due to certain characteristic such as its low domed shape, five long petals and its central periproct. The periproct opens into a groove that runs to the lower posterior of the shell.
Period: Jurassic Period
Condition: Good condition.