|Blue button (Porpita porpita)|
The most familiar members of the family Porpitidae are the blue button (Porpita porpita) and the by-the-wind sailor (Velella velella).
Chondrophores may look like a jellyfish, but they really are not. Like the siphonophores they are not a single animal. They are a colony of clones, genetically identical zooids. These zooids are small, highly modified individual polyps. Though structurally similar to other cnidarians, the zooids do not live by themselves: they are attached to each other. Each type of zooid depends for survival on the others doing what it cannot do by itself.
A rare soft-bodied fossil was got from Mississippian strata in northeastern Kentucky. It was interpreted as a chondrophorine float. The origin of the group was probably in the Neoproterozoic era, some 650–540 million years ago.
- Schuchert, Peter 2012. The hydrozoa directory. Muséum Geneve
- Yochelson, Ellis L. and Mason, Charles E. 1986. A chondrophorine coelenterate from the Borden Formation (Lower Mississippian) of Kentucky, Journal of Paleontology. 60, 5, 1025-1028.