The Echinoid Directory

• Test thick, ambitus rounded.
• Apical disc dicyclic; similar in diameter to peristome. Genital plates all similar in size. All plates densely covered in tubercles/spines.
• Ambulacral zones sinuous; pore-pairs narrow, non-conjugate. Interporal zone with larger marginal tubercles and smaller perradial tubercles generally arranged in horizontal rows.
• Interambulacral plates with perforate, non-crenulate tubercles and deeply sunken areoles surrounded by contiguous scrobicular tubercles.
• Scrobicular tubercles clearly differentiated. Dense and uniform granulation outside the scrobicular circle.
• One or both fully formed adapical plates in each interambulacral zone with a rudimentary primary tubercle. Adapical plates taller than wide.
• Interambulacral plates with small but distinct sutural pits on horizontal sutures and at triple suture junctions interradially.
• Primary spines stout, fusiform, with ornament of thorned narrow ribs.

Lower Cretaceous (Aptian) to Recent, Europe, North America, North Africa, Middle East, Indo-Pacific.

Cidaris cretosa Mantell, 1835, p. 205 [=Cidaris sceptrifera Mantell, 1822, p. 194], by subsequent designation of Lambert & Thiery, 1909, p. 152.

• S. lardyi (Desor, 1856); Berriasian - Aptian, Europe.
• S. pretiosa (Desor, 1856);
• S. malum (Gras, 1848); Aptian, Europe.
• S. dissimilis (Woodward); Albian-Cenomanian, UK.
  
• S. sceptrifera (Mantell, 1822); Turonian to Campanian; Europe.
• S. carteri (Forbes, 1856); Cenomanian, England, Germany.
• S. intermedia (Wiltshire, in Wright, 1868); Turonian - Coniacian, Europe.
• S. serrata (Desor, 1858); Upper Campanian, Europe.
• S. campaniensis (Lambert,
• S. herthae (Schlueter, 1892); Maastrichtian, Europe, Ukraine.
• S. alcocki (Anderson, 1894); Recent, Indian Ocean.
• S. capensis Doderlein, 1901; Recent, South Africa.
• S. grandis (Doderlein, 1885); Recent, Indo-Pacific.
• S. granularis Mortensen, 1928; Recent, Philippines.
• S. hawaiiensis Mortensen, 1928; Recent, Hawaii.
• S. indica Doderlein, 1901; Recent, Indian Ocean, Japan, Philippines.
• S. ingolfiana Mortensen, 1903; Recent, North Atlantic.
• S. leucacantha Agassiz & Clark, 1907; Recent, Hawaii
• S. microtuberculata (Yoshiwara, 1898); Recent, Japan.
• S. namadica Duncan, 1887; Turnonian-Coniacian, India.
• S. sceptriferoides Doderlein, 1887; Recent, Japanese Seas
• S. sulcatispina Mortensen, 1928; Recent, Indo-West Pacific.
• S. squamosa Mortensen, 1928; Recent, Indian Ocean.
• S. stylifera Mortensen, 1928; Recent, Philippines.
• S. purpurascens Mortensen, 1928; Recent, Philippines.
• S. sulcatispinis Mortensen, 1928; Recent, Philippines.
• S. tubifera Mortensen, 1928; Recent, Philippines.

Cidaroida; Cidaridae, Stereocidarinae.

Presumably paraphyletic by exclusion of T. (Temnocidaris).

The fusiform spines with their relatively dense rows of spinules distinguish Stereocidaris from T.  (Hirudocidaris), while the lack of small pits in the extrascrobicular zone of adapical interambulacral plates separates it from T. (Temnocidaris).

Pomel, A. 1883. Classification méthodique et Genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris 503, A. Jourdan, Alger, 131 pp.

Smith, A. B. & Wright, C. W. 1989. British Cretaceous echinoids. Part 1, General introduction and Cidaroida. Monograph of the Palaeontographical Society [publication no. 578, issued as part of volume 141]. 1-101, pls 1-32.