Conulariid

an extinct invertebrate, most often assigned to Coelenterata. The conulariids inhabited the seas from the early Cambrian to the early Triassic. They had a pyramid- or cigarshaped skeleton with a thin wall that was possibly elastic in life. The top part was divided by cross ridges into chambers. Fourfold symmetry is usually characteristic of the skeletal elements. The majority of conulariids led a natatorial mode of existence.