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Oxypora

Saville Kent, 1871, p. 283

Type Species

Trachypora lacera Verrill, 1864, p. 53; Subsequent Designation Wells, 1936: 122

Type Specimen: Syntype; MCZ IZ 44065, IZ 44066; Verified; Dry Preserved

Type Locality: Singapore (Recent)

Saville Kent (1871) proposed the name "Oxypora" to replace Verrill's Trachypora, because the name "Trachypora" had already been proposed by Milne Edwards.

Classification

Synonyms

Diagnosis

Colonial; laminar. Budding intracalicular. Corallites may be polymorphic; organically united and lacking distinct calical walls. Monticules absent. Coenosteum spinose; extensive amount (≥ corallite diameter). Calice width medium (4–15 mm), with low relief (< 3 mm). Costosepta mostly confluent. Septa in < three cycles (< 24 septa). Free septa irregular. Septa spaced < 6 septa per 5 mm. Costosepta unequal in relative thickness. Columellae trabecular and compact (1–3 threads), ≥ 1/4 of calice width, and discontinuous among adjacent corallites with lamellar linkage. Internal lobes absent. Epitheca absent. Endotheca low-moderate (tabular). Tooth base at midcalice elliptical-parallel. Tooth tip forming multiaxial bulb. Tooth height medium (0.3–0.6 mm). Tooth spacing medium (0.3–1.0 mm), with ≤ six teeth per septum. Tooth size equal between wall and septum. Granules scattered on septal face; weak (rounded). Interarea smooth. Walls formed by dominant paratheca and partial septotheca. Thickening deposits with extensive stereome. Costa centre clusters weak; > 0.6 mm between clusters; medial lines strong. Septum centre clusters weak; 0.3–0.5 mm between clusters; medial lines weak.

Description

'This name is proposed in place of Trachypora of A. E. Verrill (Bulletin Mus. Comp. Zoology, Cambridge, U. S. p. 53, 1863), which has been already adopted by Milne-Edwards for a genus of the Cyathophylliidæ. He separates it from Echinopora on account of the echinate and coarsely costate character of the lower surface of the corallum.' (Saville Kent, 1871: 283–284)

Comparisons

There are no unambiguous apomorphies for Oxypora, although compact columellae (1–3 threads) and the absence of distinct paliform (uniaxial) lobes are synapomorphies on the morphological phylogeny. The three representatives analysed here are nested within the clade dominated by Echinophyllia (subclade F + G sensu Arrigoni et al., 2014c), as a polyphyletic group on the molecular tree, and as a monophyly on the morphological tree. Together with Echinomorpha, these genera form a well-supported clade with a bootstrap value of 71 and decay index of 4, and are defined by four synapomorphies: (1) organically united corallites (likelihood of 0.86 based on the Mk1 model); (2) extensive coenosteum (≥ corallite diameter) (likelihood 0.75); (3) columellae ≥ 1/4 of calice width (likelihood 0.92); and (4) loss of epitheca (likelihood 0.84). Historically, the affiliation between Oxypora and Echinophyllia has been extremely close. The latter was synonymised under the former by Crossland (1952), who found no morphological traits to separate the two genera. Chevalier (1975) also placed Oxypora glabra Nemenzo, 1959: 122, under Echinophyllia based on a specimen from New Caledonia. This resulted in Oxypora lacera (Verrill, 1864: 53) being the sole species classed in Oxypora during that time. Interestingly, the position of Oxypora glabra on the molecular phylogeny does show that Oxypora glabra is more closely related to all Echinophyllia species except E. echinata, which forms a clade with Oxypora lacera and O. convoluta Veron, 2000, vol. 2: 340. The close relationship between Echinophyllia and Oxypora is further supported by the presence of alveoli, which are small pits on the exotheca forming at points of insertion of new septocostae (Chevalier, 1975; Wood, 1983; Veron, 1986; Veron, 2000; Benzoni, 2013). As explained above for Echinophyllia, the unexpected split of this group into the molecular clades F and G, not accompanied by consistent morphological variation, indicates that the Echinophyllia-Oxypora dichotomy ought to be tested with more comprehensive taxonomic and genetic sampling of Oxypora.

Remarks

Oxypora was established by Saville Kent (1871: 283) to replace Trachypora Verrill, 1864: 53, which was represented by Trachypora lacera Verrill, 1864: 53, but had already been used by Milne Edwards and Haime (1851a, vol. 5: 158) for a Devonian tabulate coral (Wells, 1936). Saville Kent's proposal was probably unknown to Klunzinger (1879), who placed Trachypora lacera in Echinophyllia Klunzinger, 1879: 69 (Quelch, 1886). Partly as a result of this affiliation, Oxypora was grouped by Wells (1935) with Echinophyllia, Tridacophyllia de Blainville, 1830: 327 (= Pectinia de Blainville, 1825: 201), Mycedium, and Physophyllia Duncan, 1884: 118, in Tridacophylliidae Thiel, 1932: 96, which was originally placed in Fungida (see Yabe and Eguchi, 1935b). Trachypora lacera was later designated as the type of Oxypora by Wells (1936), validating it as a separate genus from Echinophyllia. Oxypora was placed in the newly-established Pectiniidae by Vaughan and Wells (1943: 196), along with the five Tridacophylliidae genera above. Until relatively recently, this classification remained stable (e.g. Wells, 1956; Nemenzo, 1959; Chevalier, 1975; Wood, 1983; Veron, 2000). Molecular-based phylogenies have indicated that Pectinia, Mycedium and Physophyllia are in the Merulinidae clade, distinct from the sister groups comprising Echinophyllia and Oxypora (subclade F + G sensu Arrigoni et al., 2014c) that are nested within Lobophylliidae (clade XIX sensu Fukami et al., 2008; Arrigoni et al., 2014b, c, 2015, 2016a). Consequently, Pectiniidae has been synonymised (Budd et al., 2012; see also Huang et al., 2011, 2014b; Arrigoni et al., 2012). Oxypora is widely distributed on the reefs of Indo-Pacific, present from the Red Sea and East Africa to as far east as the Marshall Islands in the Northern Hemisphere and Samoa in the Southern Hemisphere (Veron, 2000).

Distribution

  • West Asia; Miocene
  • Southeast Asia; Miocene
  • Melanesia; Pliocene
  • East Asia; Pleistocene
  • Southeast Asia; Pleistocene
  • Indian Ocean; Recent
  • Western Pacific; Recent
  • Central Pacific; Recent
  • East Asia; Holocene
Source: Paleobiology database (accessed 6-18-12), Veron (2000). Historical distribution: Recent., Pacific (Wells 1956). Distribution compiled by Matthew Tibbits.

This page has been in preparation since 20-Jul-2010 03:59

This version was contributed by Danwei Huang on 29-Jan-2016 14:00.

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


holotype of Trachypora lacera Verrill
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holotype of Trachypora lacera Verrill
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holotype of Trachypora lacera Verrill
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