The Echinoid Directory

• Test domed in profile.
• Apical disc relatively small, dicyclic, with 5 gonopores; hydropores confined to genital plate 2. Periproct opening oval.
• Ambulacra straight.  Above the ambitus plating is simple with all elements subequal and reaching the perradius.  At the ambitus and adorally plates are trigeminate with compounding in the diadematoid style.  These compound plates bear a large primary tubercle, but plates above the ambitus have only dense uniform granulation.
• Pore-pairs uiserially arranged at the ambitus and aborally; expanded into short phyllodes adorally.  Pore-pairs above the ambitus distinctly larger than adorally.
• Interambulacral plates wider than tall.  Two subequal primary tubercles on ambital and subambital plates .  Above the ambitus plates are covered in a fine, dense, uniform granulation.
• Primary tubercles imperforate and non-crenulate.
• Peristome large with shallow scalloped buccal notches.
• lantern and spines unknown.

Lower Jurassic (Pliensbachian), Morocco.

Baronechinus baroni Vadet & Nicolleau, 2005, p. 29, by original designation.

Only the type species.

Euechinoidea, Echinacea, Stomechinidae

This taxon appears very similar to some arbacioids, such as Codiopsis, in having enlarged aboral pores uniserially arranged.  However, its ambulacral plating is very different, with all three elements in a triad equal in size and extending to the median suture.
Very close to Diplechinus, which occurs at the same horizon, but without such well differentiated zones of tuberculation style.

Vadet, A. & Nicolleau, P. 2005. Les oursins Domeriens de la region de Rich (Maroc). Annales de la Societe d\'Histoire Naturelle du Boulonnais 5(1), Echinides nouveaux peu ou mal connus Tome II, fascicule 5, pp. 1-36.