The Echinoid Directory

Agassizia Valenciennes, in Agassiz & Desor, 1847, p. 20

[= Agassisia Valenciennes, in Du Petit-Thouars, 1846 (original incorrect spelling); ?=Eoagassizia Grant & Hertlein, 1938, p. 115, type species E. alta A. Clark in Grant & Hertlein, 1938 ]

Diagnostic Features	Test ovate with no anterior sulcus at ambitus; rounded in profile. Apical disc ethmolytic, with 4 gonopores; central. Anterior ambulacrum narrow and weakly depressed adapically; pore-pairs specialised bearing small penicillate tube-feet; uniserially arranged. Other ambulacra petaloid and weakly sunken, anterior petals considerably longer than posterior petals and flexed anteriorly; anterior column with rudimentary pore-pairs; anterior and posterior columns made up of the same number of plates. Posterior petals shorter; weakly depressed and with both columns equally developed in type species (A. excentrica has reduced pores in the outer column). Periproct on vertical, truncate face. Two or three subanal penicillate tube-feet. Peristome large and D-shaped; labral plate not projecting strongly and peristome facing downwards. Labral plate short and wide; not extending beyond first ambulacral plate; in broad contact with both sternal plates. Aboral tuberculation fine, uniform and dense. Oral tubercles also dense and uniform. Well-developed peripetalous fasciole passing a little below the anterior petals (ca. 3 plates below end) and inframarginal anteriorly, crossing plate 3 in anterior interambucrum. Lateroanal fasciole present.
Distribution	Middle Eocene to Recent, North America, Caribbean, Middle East, East Pacific. Shallow water silts and muds - infaunal.
Name gender	feminine
Type	Agassizia scrobiculata Val. Agassiz & Desor, 1847, p. 20, by original designation [Valenciennes reference to this genus the year before is a nomen nudum].
Species Included	A. scrobiculata Valenciennes, 1846; Recent, west coast of central America, Galapagos. A. algarbiensis Ferreira, 1961; Miocene, Portugal. A. excentrica Agassiz, 1869; Recent, Caribbean. A. powersi Kier, 1972; Miocene, Dam Formation, Saudi Arabia. A. wilmingtonica Cooke, 1942; Middle Eocene, South East USA. A. persica Clegg, 1933; Middle Miocene, Qatar. A. lovisatoi Cotteau, 1895; Lower and Middle Miocene, France, Sardinia. A. alta Grant & Hertlein, 1938; Eocene, California USA.
Classification and/or Status	Spatangoida, Paleopneustina, Prenasteridae. Presumed monophyletic.
Remarks	Differs from Anisaster in having no respiratory tube-feet (and associated pore-pairs) in the anterior column of the anterior paired petals. Prenaster also lacks a frontal groove, but its apical disc lies much closer to the anterior border and the paired anterior petals diverge at almost 180 degrees. Agassiz, L. & Desor, E. 1846-1847. Catalogue raisonné des familles, des genres, et des espèces de la classe des échinodermes. Annales des Sciences Naturelles, Troisième Série, Zoologie: 6 (1846), 305-374, pls 15-16; 7 (1847), 129-168; 8 (1847), 5-35, 355-380. Mortensen, T. 1951 A. monograph of the Echinoidea. V. Spatangoida 2. C. A. Reitzel, Copenhagen. Kier, P. M. 1972. Tertiary and Mesozoic echinoids of Saudi Arabia. Smithsonian Contributions to Paleobiology 10, 1-242. Kier, P. M. 1980. The echinoids of the Middle Eocene Warley Hill Formation, Santee Limestone and Castle Hayne Limestone of North and South Carolina. Smithsonian Contributions to Paleobiology 39, 1-102.