Milne Edwards and Haime, 1851, p. 130

Mycedium was originally described by Oken (1815). According to ICZN Opinion 417 (September 1956), the names originally proposed by Oken (1815) are rejected. Therefore authorship is assigned to the second person who used the name.

Type Species

Madrepora elephantotus Pallas, 1766, p. 290; Subsequent Designation Verrill, 1901, p. 133

Type Specimen: Neotype; RMBR ZRC.CNI.0916; Verified; Dry Preserved

Type Locality: Raffles Light, Singapore ('Oceanus Indicus'; Pallas, 1766, p. 290) (Recent)

The holotype of Madrepora elephantotus Pallas, 1766, p. 290, is lost (Chevalier, 1975, p. 338).




Colonial, with intracalicular budding only. Corallites polymorphic and organically united; monticules absent. Coenosteum costate, extensive amount (≥ corallite diameter). Calice width medium (4–15 mm), with medium relief (3–6 mm). Costosepta confluent. Septa in 3 cycles (24–36 septa). Free septa present but irregular. Septa spaced < 6 septa per 5 mm. Costosepta unequal in relative thickness. Columellae trabecular and spongy (> 3 threads), < 1/4 of calice width, and discontinuous among adjacent corallites (lamellar linkage). Paliform (uniaxial) lobes weak or moderate. Epitheca absent and endotheca abundant (vesicular). Tooth base at mid-calice circular. Tooth tip at mid-calice irregular; tip orientation perpendicular to septum. Tooth height medium (0.3–0.6 mm) and tooth spacing medium (0.3–1 mm), with no more than 6 teeth per septum. Granules scattered on septal face; irregular in shape. Interarea formed by horizontal bands. Walls formed by dominant paratheca; abortive septa absent. Thickening deposits micro-fibrous. Costa center clusters not distinct; medial lines strong. Septum center clusters not distinct; medial lines strong. Transverse crosses absent. Columella centers clustered.


'Polypier en expansions frondiformes. Calices circonscrits, penchés, submamillaires, et disposés autour de l'individu parent qui reste plus développé que les autres. Plateau commun nu et costulé.' (Milne Edwards and Haime, 1851, vol. 15: 130)


Organically united corallites appear to have independently evolved twice, within Merulinidae in Mycedium + Pectinia, and within Lobophylliidae in Echinophyllia + Oxypora (Budd et al., 2012: fig. 2B). Other synapomorphies of the Mycedium + Pectinia clade are polymorphic corallites, extensive coenosteum, unequal costosepta thickness, discontinuous columellae (lamellar linkage), not more than 6 teeth per septum, interarea made up of horizontal bands, and micro-fibrous deposits. Transverse crosses are also lost in this lineage. The clade is highly supported. Mycedium and Pectinia share all morphological traits examined here, as opposed to the paraphyletic Pectinia recovered by molecular data. Physophyllia is also extremely similar on the basis of macromorphology. The lack of distinction between these three genera, and the paraphyly of Pectinia may be grounds for regarding Mycedium as a synonym of Pectinia and/or Physophyllia, but as Mycedium elephantotus remains the only species placed on the morphology tree, no changes are proposed here. Note that quantitative measurements were based on peripheral corallites as structures of the central corallite may be extremely large in comparison.


This genus has commonly been regarded to be similar to Echinophyllia (Lobophylliidae), because of its laminar growth form (Vaughan and Wells, 1943: 198; Wells, 1956: F419; Veron and Pichon, 1980: 319; Veron, 1986: 382; Veron, 2000, vol. 2: 342). The lack of distinct corallite walls, or corallites being 'organically united' (Vaughan and Wells, 1943: 196), is a distinguishing feature of Pectiniidae, the family in which Mycedium and Echinophyllia were placed prior to revision by Budd et al. (2012). It is now clear based on molecular phylogenetics that this genus is closest to and also nested within Pectinia de Blainville, 1825: 201 (Fukami et al., 2008; Huang et al., 2011, 2014; Huang, 2012; Arrigoni et al., 2012).


  • Southeast Asia; Miocene - Pliocene
  • Southeast Asia; Pliocene
  • North Africa; Pleistocene
  • East Asia; Pleistocene
  • Australasia; Pleistocene
  • West Asia; Pleistocene
  • Southeast Asia; Pleistocene
  • Indian Ocean; Recent
  • Western Pacific; Recent
  • Central Pacific; Recent
Source: Paleobiology database (accessed June 13, 2012), Veron (2000). Historical distribution: Recent., Pacific (Wells, 1956). Distribution compiled by Matthew Tibbits. Recent: Mycedium is widely distributed on reefs of the Indo-Pacific, present as far east as the Gambier Islands in the southern hemisphere (Glynn et al., 2007), but absent eastwards from Hawai'i in the north.

This page has been in preparation since 06-Oct-2009 22:33

This version was contributed by Danwei Huang on 05-Feb-2014 22:54.

Page authors are: Ann Budd Danwei Huang. Please contact the editor if you would like to contribute to the diagnosis of this taxon.

The editor is: Ann Budd

Neotype of Mycedium elephantotus (Pallas, 1766)