The Echinoid Directory

• Test cordate with modest frontal sulcus running from apex to peristome.
• Apical disc ethmolytic, with 3 gonopores (no gonopore in genital plate 2).
• Anterior ambulacrum narrow and sunken adapically. Pore-pairs uniserial and enlarged adapically.
• Other ambulacra with parallel-sided and sunken petals. Petals ending some distance from the ambitus. One or more occluded plates at the petal ends.
• Periproct towards top of short vertically-truncate posterior face.
• Peristome ovate to kidney-shaped with labral plate projecting to a greater or lesser extent.
• Labral plate generally not much longer than wide; extending to second ambulacral plate. Sternal plates triangular and fully tuberculate. Succeeding episternal plates subquadrate and a little offset.
• Interambulacrum 1 amphiplacous (two plates abut basicoronal plate).
• No primary tubercles differentiated. Aboral tuberculation set in groundmass of fine granules.
• Peripetalous and marginal fascioles developed; independent in type species. Marginal fasciole crossing plate 4a,b in all interambulacra. Peripetalous fasciole deeply indented behind anterior petals.

Lower Eocene to Recent, worldwide.

Hemiaster (Pericosmus) latus Desor, in Agassiz & Desor, 1847, p. 19, by subsequent designation of de Loriol, 1875, p. 115.

• P. latus (Agassiz & Desor, 1847); Lower - Middle Miocene, circum-Mediterranean.
• P. macronesicus Koehler, 1914; Recent,
• P. cordatus Mortensen, 1950; Recent,
• P. bidens Mortensen, 1950; Recent,
• P. tenuis Mortensen, 1950, Recent,
• P. keiensis Mortensen, 1950; Recent,
• P. mauritanus Mortensen, 1950; Recent
• P. oblongus Mortensen, 1950; Recent,
• P. porphyrocardius McNamara, 1984; Recent, NW shelf of Australia.
• P. celsus McNamara & Philip, 1984; Middle Miocene, Australia
• P. compressus (Duncan, 1877); Middle Miocene, Murray Basin, Australia.
• P. maccoyi Gregory, 1890; Late Oligocene, early Miocene, Mount Gambier, South Australia.
• P. quasimodo McNamara & Philip, 1984; Middle Miocene, Australia
• P. torus McNamara & Philip, 1984; Early to Middle Miocene, Victoria, Australia.
• P. crawfordi (Hutton, 1873); Oligocene - Lower Miocene, New Zealand.
• P. borraeus Henderson, 1975; Lower Miocene, New Zealand.
• P. scaevus Henderson, 1975; Lower Miocene, New Zealand.
• P. fallati (Mazzetti, 1882); Miocene, Italy.
• P. annosus Henderson,1975; Upper Eocene, New Zealand.
• P. granulosus Herklots, 1854; Miocene, Java.
• P. cameli Bajarunas, 1969; Ypresian, Lower Eocene, Mangyshlak.

Spatangoida, Paleopneustina, Pericosmidae.

Possibly paraphyletic (by exclusion of Faorina).

The Recent species were mostly described by Mortensen (1951), with additions by McNamara (1984). A general revision of the genus and overview of fossil species was given by McNamara & Philip (1984). Pericosmus differs from Faorina primarily in having its interambulacra all amphiplacous adorally. In Faorina plating in interambulacrum 1 is meridoplacous and the marginal fasciole is often incomplete or absent in adults.

Agassiz, L. & Desor, P. J. 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.

McNamara, K. J. 1984. Living Australian species of the echinoid Pericosmus (Spatangoida: Pericosmidae). Records of the Western Australia Museum 11, 87-100.

McNamara, K. J. & Philip, G.M. 1984. A revision of the spatangoid echinoid Pericosmus from the Tertiary of Australia. Records of the Western Australia Museum 11, 319-356.

Mortensen, T. 1951. A monograph of the Echinoidea V. Spatangoida 2. C. A. Reitzel, Copenhagen.