From Wikipedia, the free encyclopedia
Jump to: navigation, search
Eucidaris tribuloides (Slate-pencil Urchin).jpg
Eucidaris tribuloides on a brain coral
Scientific classification
Kingdom: Animalia
Phylum: Echinodermata
Class: Echinoidea
Subclass: Perischoechinoidea
Order: Cidaroida
Family: Cidaridae
Genus: Eucidaris
Pomel, 1883[1]
Type species
Cidarites monilifera Goldfuss, 1829
See text

Eucidaris is a genus of cidaroid sea urchins known as slate pencil urchins. They are characterised by a moderately thick test, a usually monocyclic apical disc, perforate and non-crenulate tubercles and nearly straight ambulacra with horizontal pore pairs. The primary spines are few and widely spaced, stout with blunt flat tips and beaded ornamentation and the secondary spines are short and apressed. They originated in the Miocene and extant members of the genus are found in the tropical Indo-Pacific Ocean, East Pacific, Atlantic Ocean and Caribbean Sea.[2]


The World Register of Marine Species lists the following species:[1]

Species brought into synonymy
  • Eucidaris clavata Mortensen, 1928: synonym of Eucidaris tribuloides (Lamarck, 1816)


  1. ^ a b Kroh, Andreas (2012). "Eucidaris Pomel, 1883". World Register of Marine Species. Retrieved 2013-03-22. 
  2. ^ "Eucidaris Pomel, 1883". The Echinoid Directory. The Natural History Museum. Retrieved 2013-03-22.