The Echinoid Directory

Temnocidaris (Hirudocidaris) Smith & Wright, 1989, p. 78.

[= Hirudocidaris Smith & Wright, 1989, p. 78]

Diagnostic Features	Apical disc opening similar in diameter to peristome; plating unknown. Ambulacra weakly sinuous; pore-pairs not conjugate with the interporal ridge not much larger than a pore. Perradial zone with horizontal row of subequal tubercles. Interambulacral zones with single adapical plate with rudimentary tubercle. Primary tubercles perforate and non-crenulate (adapical tubercles with traces of crenulation on their adapical side). Areoles sunken. Scrobicular tubercles fully developed; areoles circular and separated throughout. Extrascrobicular zones moderately well developed and densely covered in uniform secondary tubercles. Small pits on horizontal plate sutures in interambulacral zones. Primary spines shorter than test diameter; fusiform; ornamented with rather sharp, weakly beaded ribs; ending in small cap.
Distribution	Cretaceous (Upper Albian to Campanian); Europe.
Name gender	feminine
Type	Cidaris hirudo Sorignet, 1850, p. 17, by original designation.
Species Included	H. uniformis (Sorignet, 1850): Upper Albian to Cenomanian, western Europe. H. hirudo (Sorignet, 1850); Turonian to Campanian, Europe. H. silesiaca (Schlueter, 1892); Turonian to Coniacian, Europe.
Classification and/or Status	Cidaroida; Cidaridae; Stereocidarinae. Monophyletic; a subgenus of Temnocidaris.
Remarks	Close to Temnocidaris (Stereocidaris) but distinguished by the form of its spines: those of Hirudocidaris are short and ornamented with rather well-developed narrow ribs, while those of Stereocidaris are elongate and swollen near the base, with rather well-developed rows of thorns. 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].