The Echinoid Directory

Pseudopygurus Lambert, 1911, p. 184

Diagnostic Features	Test large, low, greatest height anterior at apical system, greatest width posterior of centre, anterior margin blunted, posterior pointed, outline roughly pentagonal. Apical system anterior, tetrabasal. Petals flush with test, petals II and IV extending two-thirds distance to margin, petals I and V slightly longer, extending over one-half distance to margin. In paired petals, outer pores very elongate transversely, inner pore slightly elongate transversely, pores strongly conjugate, interporiferous zone twice as wide as poriferous, petals closing distally. Anterior ambulacrum non-petaloid or subpetaloid, with narrower poriferous zones, interporiferous zones wide. Peristome, anterior, longitudinal, pentagonal; ambulacra slightly sunken and interambulacra raised towards peristome. Periproct longitudinal, on oral surface close to posterior margin. Bourrelets well developed. Phyllodes double pored, with three series of pore pairs in each half ambulacrum. No buccal pores.
Distribution	Middle to Upper Jurassic (Callovian - Oxfordian) of France, North Africa and Middle East.
Name gender	masculine
Type	Pseudopygurus letteroni Lambert, 1911, p. 184, by monotypy.
Species Included	P. letteroni Lambert, 1911; Oxfordian,France. P. ambroggii Petitot, 1954; Oxfordian, Algeria and Morocco. P. hathirae Parnes, 1961; Middle Callovian, Israel.
Classification and/or Status	Irregularia; Neognathostomata; 'pygurid'. Subjective junior synonym of Pygurus.
Remarks	Pseudopygurus is very similar to Pygurus, but differs in the reduction of petal III (Kier, 1962). Lambert (1911) stated that ambulacrum III was not petaloid in his species. However, Kier (1962) correctly points out that although petal III is much narrower than the other petals and its outer pores much less elongated, its pores are much larger than those occurring in the ambulacral plates beyond the petals, and should therefore be considered to be subpetaloid. Specimens of Pseudopygurus in the Lambert Collection in Paris show considerable variation in the degree to which ambulacrum III is petaloid. These specimens appear to form a morphological series, and should be considered morphotypes of the same species. P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144 (3) 262 pp. J. Lambert. 1911. Note sur quelques echinides eoceniques des Corbieres septentrionales. Annales de l'Universite de Lyon 30, p. 184.