First appearing in the Precambrian era, these invertebrates possess a central digestive cavity, and radial symmetry.
First appearing in the Precambrian era, these invertebrates possess a central digestive cavity, and radial symmetry. They are divided into four major groups – anthozoa, hydrozoa, cuboza, and scyphozoan. Their name is derived from them Greek for "stinging nettle" and they are characterized by the presence of stinging cells called nematocysts. For ten points, identify this phylum that includes siphonophores, medusas, hydroids, and jellyfish.
First appearing in the Precambrian era, these invertebrates possess a central digestive cavity, and radial symmetry.
Cnidaria (Also accept Coelenterata, though technically colenterates include animals that Cnidaria does not)