The Echinoid Directory

Tripneustes L. Agassiz, 1841, p. 7

[ =Hipponoe Gray, 1840, p. 65 (nomen nudum), non Hipponoe Audouin & Milne Edwards, 1830; =Heliechinus Girard, 1850, type species Heliechinus Gouldii Girard, 1850 by monotypy (= Echinus ventricosus Lamarck) (subjective).]

Diagnostic Features	Apical disc hemicyclic, without suranal plate in adults. Ambulacral plating trigeminate, with pore-pairs in three distinct columns throughout, these columns being separated by bands of tubercles (juveniles have simple arcs of pore-pairs). Primary tubercle on every third or fourth ambulacral plate only. Interambulacra with small primary tubercle on most but not all plates; secondary tubercles sparse and not regularly developed; plates appear rather naked. Adapical interradial and perradial zones devoid of tubercles. Buccal notches sharp and pronounced. Auricles joined perradially.
Distribution	Miocene to Recent, Caribbean, West coast of America, including Galapagos Islands, Southern Europe, Mediterranean and North Africa, and throughout the Indo-Pacific.
Name gender	feminine
Type	Tripneustes ventricosus (Lamarck, 1816) by monotypy.
Species Included	T. ventricosus (Lamarck, 1816); Recent, Caribbean and Atlantic - littoral to 30 m. T. depressus A. Agassiz, 1863; Recent, Gulf of California, West Coast of Mexico, Galapagos Islands and Clarion Island. T. gratilla (Linneus, 1758); Recent; Indo-Pacific- littoral to 75 m (with subspecies - see Dafni 1983). [Tripneustes fuscus Michelin, 1865 is a junior synonym] T. antiquus Duncan & Sladen, 1855; Miocene of Pakistan. T. proavia Duncan & Sladen, 1855; Miocene of Pakistan. T. parkinsoni L. Agassiz, Miocene of southern France. T. gahardensis (Seunes); middle and late Miocene of France and Spain. T. Schneideri Boehm, Miocene ** T. tobleri Jeannet, 1928; Miocene of Venezuela. T. californicus Kew, 1920; Pliocene of California.
Classification and/or Status	Camarodonta; Echinoida; Toxopneustidae. Monophyletic.
Remarks	The ambulacral structure, combined with the rather deep and sharp buccal notches make this readily identifiable in the fossil record. Only Toxopneustes has similar vertical pore-pair series and deep buccal notches, but in that species there are multiple subequal tubercles on interambulacral plates. Lytechinus tests are rather similar in tuberculation style but have a very different ambulacral pore-pair arrangement. Mortensen, T. (1943) A monograph of the Echinoidea Part III.2, Camarodonta 1. C. A. Reitzel, Copenhagen. Dafni, J. (1983) A new sub-species of Tripneustes gratilla (L.) from the northern Red Sea (Echinodermata: Echinoidea: Toxopneustidae).Israeli Journal of Zoology 32:1-12.