The Echinoid Directory

Pygurus L. Agassiz, 1839, p. 68

[=Pseudopygurus Lambert, 1911, p. 184, type species Pseudopygurus letteroni Lambert, 1911; =Kieripygurus Vadet, 1997, p. 59, type species Pygurus jurensis Marcou, 1848 ]

Diagnostic Features	Test large, inflated, posterior margin prolonged, greatest height at apical system. Apical disc tetrabasal, anterior; genital plates large, extending posteriorly, posterior ocular plates typically in contact, four gonopores. Petals broad, long, closed distally; poriferous zones wide with conjugate pores, outer pore slit-like; ambulacral pores all double pored. The petal of ambulacrum III is generally less well developed than those of the paired ambulacra. Periproct inframarginal, longitudinal, with anterior side of opening slightly pointing, posterior blunt. Peristome anterior, pentagonal; with vertical-walled entrance. Bourrelets well developed; ambulacra slightly sunken and interambulacra slightly raised towards peristome. Phyllodes broad, depressed, all double pored, with three series of pore pairs in each half ambulacrum, the first pore pairs in a phyllode widely separated from the edge of the peristome. No buccal pores. Tubercles on adoral surface larger than those on adapical surface.
Distribution	Jurassic (Oxfordian) to Cretaceous (Cenomanian), world wide distribution.
Name gender	masculine
Type	Echinolampas montmollini L. Agassiz, 1836, p. 134, by subsequent designation of Savin, 1902, p. 271.
Species Included	P. (Pygurus) montmollini (L. Agassiz, 1836a); Valanginian, France and Switzerland. P. (P.) blumenbachii (Koch & Dunker, 1837); Oxfordian-Kimmeridgian, Europe. P. (Pygurus) complanatus Tanaka, 1965; Lower Cretaceous, Japan. P. costatus Wright, 1861; Oxfordian, England. P. (Pygurus) letteroni (Lambert, 1911); Callovian - Oxfordian of France, North Africa and Middle East. P. (Pygurus) jurensis Marcou, 1848; Callovian - Valanginian, Europe and North Africa.
Classification and/or Status	Irregularia; Neognathostomata; \'pygurid\'.
Remarks	Kier (1962) restricts Pygurus to those taxa with a somewhat inflated test, an anterior apical system, broad, depressed phyllodes, with from one to three series in each half ambulacrum, with the first pore pairs in a phyllode widely separated from the edge of the peristome. Mepygurus differs from Pygurus by having a low, broad test, with a central or slightly anterior apical system, slightly depressed and not broadened phyllodes with three or four series of pore pairs in each half ambulacrum, and with the first pore pair in a phyllode near the edge of the peristome. P. M. Kier 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144 (3) 262 pp. Agassiz, L. 1839. Description des Échinodermes fossiles de la Suisse. Première partie, Spatangoides et Clypéasteroides. Mémoires de la Société helvétique des Sciences naturelles, 3, i-viii + 1-101, 14 pls. Barras, C. G. 2006. British Jurassic irregular echinoids. Monograph of the Palaeontographical Society no. 625 (part of volume 159 for 2005), 1-168, pls 1-14.