Oulophyllia

Milne Edwards and Haime, 1848, p. 492

Type Species

Meandrina crispa Lamarck, 1816, p. 247; Original Designation Milne Edwards and Haime, 1848, p. 492

Type Specimen: Holotype; MNHN IK-2010-526; Verified; Dry Preserved

Type Locality: 'lOcéan indien?' (Lamarck, 1816, p. 247) (Recent)

Classification

• Family: Merulinidae Verrill, 1865, p. 146

Synonyms

• Coelogyra Nemenzo, 1959, p. 109
• Ulophyllia Milne Edwards and Haime, 1857, p. 377

Diagnosis

Colonial, with intracalicular budding only. Corallites monomorphic and discrete (1–3 centers) or uniserial; monticules absent. Walls fused. 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 equal in relative thickness. Columellae trabecular and spongy (> 3 threads), < 1/4 of calice width, and continuous among adjacent corallites. 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 > 6 teeth per septum. Granules scattered on septal face; irregular in shape. Interarea palisade. Walls formed by dominant paratheca; abortive septa absent. Thickening deposits fibrous. Costa center clusters not distinct; medial lines strong. Septum center clusters not distinct; medial lines strong. Transverse crosses present. Columella centers clustered.

Description

'Diffère du précédent [Tridacophyllia = Pectinia] par des murailles beaucoup moins élevées, par la présence d'une columelle spongieuse bien marquée, et par des cloisons très-granulées dont le bord est très-profondément divisé, surtout inférieurement.' (Milne Edwards and Haime, 1848, vol. 27: 492)

Comparisons

Oulophyllia is a moderately supported clade, and the singular synapomorphy is wall fusion, with a two-step change from moderate coenosteum to fused walls at its most recent common ancestor with Caulastraea. The genus is frequently associated with Favites and Platygyra, primarily because of their cerioid corallites (Vaughan and Wells, 1943: 169; Veron, 1986: 498, 2000, vol. 3: 195). The phylogeny based on both molecular and morphological evidence clearly shows this trait arising at least three times independently within Merulinidae, in the lineages represented by Favites + Platygyra, Coelastrea and Oulophyllia. The initial placement of Oulophyllia bennettae in Favites also underscores the homoplastic nature of this character (see remarks for Favites above). Another homoplastic character exemplified by this genus is corallite integration, which is polymorphic in this genus (uniserial in Oulophyllia crispa and O. levis; discrete in O. bennettae), Goniastrea and Platygyra. Among close relatives, these features may still be useful distinguishing characters, separating Oulophyllia from Caulastraea (phaceloid) and Pectinia + Mycedium (extensive coenosteum), as well as Oulophyllia and Caulastraea from Pectinia + Mycedium (organically united corallites). Few subcorallite characters are distinct for Oulophyllia within this clade, but a combination of medium tooth height (0.3–0.6 mm), more than 6 teeth per septum, palisade interarea and transverse septal crosses would be diagnostic.

Remarks

Oulophyllia Milne Edwards and Haime, 1848, vol. 27: 492 is a small genus that has been recovered genetically as a well-supported clade (Fukami et al., 2004; Huang et al., 2009, 2011; but see Fukami et al., 2008; Arrigoni et al., 2012). It was established for the type species O. crispa, and compared to Pectinia as having lower walls and more spongy columellae (Milne Edwards and Haime, 1848, vol. 27: 492). The walls of Pectinia however refer to laminae that project upwards and may contain corallites formed by budding. Their corallites are organically united and thus the laminae may not be considered homologous to the walls of Oulophyllia, or other discrete or uniserial taxa. In spite of this, the two genera are indeed closely related, and together with Caulastraea and Mycedium form a well-supported molecular clade (Fukami et al., 2008; Huang et al., 2011; Arrigoni et al., 2012). Only Oulophyllia crispa and O. bennettae have been studied phylogenetically. The third species, O. levis, is very similar to the type in terms of macromorphology, differing only in having smaller valleys and less developed columellae (Veron, 2000, vol. 3: 198). In fact, it was originally described as having no columellae, with a 'loose mass of septal spines' in its place (Nemenzo, 1959: 109), thus expanding the morphological range specified by Milne Edwards and Haime, 1848, vol. 27: 492.

Distribution

• Southern Europe; Oligocene
• South Asia; Miocene
• Caribbean; Miocene
• Southeast Asia; Miocene
• Southeast Asia; Pliocene - Pleistocene
• East Asia; Pliocene
• Melanesia; Pliocene
• Southeast Asia; Pliocene
• East Asia; Pleistocene - Holocene
• East Asia; Pleistocene
• Australasia; Pleistocene
• Melanesia; Pleistocene
• Indian Ocean; Recent
• Western Pacific; Recent
• Central Pacific; Recent
• Micronesia; Holocene

This page has been in preparation since 04-Oct-2009 01:26

This version was contributed by Danwei Huang on 05-Feb-2014 23:18.

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