Taxonomy

Paraconularia subtilis is the first ever conulariid specimen ever described. Conulariids are extinct marine organisms their fossils are found in rocks that are between about 500 and 200 million years old.

Shells

Paraconularia subtilis shells like all conulariids are

  • four-sided in the shape of a tall pyramid
  • made of calcium phosphate, like bones of vertebrates. 
  • grow from the pointed apex
    • adding new material is added to the edge of the open aperture
  • strongly ribbed
    • each rib formed by a new growth increment like a tree ring
Relatives

For a long time the place of Paraconularia subtilis and other conulariids in the tree of life was unknown. 

It is now believed that Paraconularia subtilis and other conulariids were relatives of 

  • sea-anemones
  • corals 
  • jellyfish

 The closest relatives of conulariids are jellyfish. Conulariids representing  the fixed, so-called polyp stage of extinct jellyfish.