Australophyllia
Benzoni and Arrigoni, 2016, p. 421
Type Species
Symphyllia wilsoni Veron, 1985, p. 167, figs 18–22; Original Designation Arrigoni et al., 2016
Type Specimen: Holotype; WAM Z910; Verified; Dry Preserved
Type Locality: Rat Island, Houtman Abrolhos Islands, Western Australia
Classification
Diagnosis
Colonial; submassive or massive. Budding intracalicular and extracalicular. Corallites monomorphic; uniserial. Monticules may be present. Walls fused. Calice width usually medium (4–15 mm), with medium relief (3–6 mm). Costosepta mostly confluent. Septa in ≥ four cycles (≥ 48 septa). Free septa irregular. Septa spaced 6–11 septa per 5 mm. Costosepta unequal in relative thickness. Columellae trabecular and spongy (> three threads), < 1/4 of calice width, and discontinuous among adjacent corallites with lamellar linkage. Internal lobes usually absent. Epitheca well developed. Endotheca low-moderate (tabular). Tooth base at midcalice elliptical-parallel. Tooth tip orientation parallel. Tooth height medium (0.3–0.6 mm), but may be slightly taller. Tooth spacing medium (0.3–1.0 mm), with > six teeth per septum. Tooth shape equal between first and third order septa. Tooth size equal between wall and septum. Granules scattered, sometimes distributed uniformly, on septal face; weak (rounded). Interarea smooth. Walls formed by dominant paratheca and partial septotheca. Thickening deposits in concentric rings with extensive stereome. Costa centre clusters strong; > 0.6 mm between clusters; medial lines weak. Septum centre clusters weak; > 0.5 mm between clusters; medial lines weak.
Description
'Colonial with submassive to massive coralla. Budding intracalicular and extracalicular. Corallites monomorphic. Corallite uniserial and discrete. Monticules present. Calice width medium (4 – 15 mm). Septa in more than four cycles (≥ 48 septa). Free septa irregular. Between 6 and 11 septa per 5 mm. Costosepta unequal in relative thickness. Adjacent corallite centers discontinuous with lamellar linkage. Columellae trabecular and spongy, < 1/4 of calice width in series although it can be larger in monocentric corallites. At midcalice tooth base elliptical-paral- lel and tooth tip irregular. Septal teeth height medium (0.3 – 0.6 mm). Tooth space medium (0.3 – 1 mm). Interarea smooth. Granules weak, rounded, scattered on septal face. Tooth shape equal between first and third order septa. Tooth size equal between midcalice and inner end in the first two cycles of septa.' (Arrigoni et al., 2016a: 422)
Comparisons
Three autapomorphies, all macromorphological traits, unambiguously define this monotypic genus: exclusively intracalicular budding, presence of monticules, and uniserial corallites. Australophyllia is closely related to Homophyllia and Micromussa, forming a sister taxon to Homophyllia + Micromussa based on molecular data, but a paraphyletic grade with morphological data, Micromussa being the earliest-branching clade. As such, it appears to have an intermediate morphology between Micromussa and Homophyllia, particular with respect to calice width and relief, number of septa, septal tooth height and spacing, as well as uniformity of granule distribution. It shares all other morphological traits (excluding the autapomorphies) with Homophyllia, therefore positioning it between Micromussa and Homophyllia in the grade. Whilst it superficially resembles Symphyllia (= Lobophyllia), in which Australophyllia wilsoni was placed, it can be distinguished easily by the presence of monticules (or broken walls), smaller calices and septa spacing, well-developed epitheca, low-moderate endotheca, lower septal teeth and narrower tooth spacing, similar tooth shape between first and third order septa, comparable tooth size between wall and septum, as well as smooth interarea.
Remarks
Australophyllia was described by Benzoni and Arrigoni in Arrigoni et al. (2016a) to contain the phylogenetically distinct Symphyllia wilsoni Veron, 1985, as a newly-discovered lineage (subclade J). Instead of grouping with its congenerics or the Lobophyllia species (subclade I) as defined in this study, it has been recovered close to Homophyllia and Micromussa based on molecular (Arrigoni et al., 2016a) and morphological data. No other species have been found with a closer relationship relative to Homophyllia or Micromussa despite near-complete sampling of the members of Symphyllia sensu Veron (2000). Australophyllia is restricted to the reefs of southern and Western Australia (Veron, 2000; Arrigoni et al., 2016a).
Distribution
- Indian Ocean; Recent
- Western Pacific; Recent
This page has been in preparation since 20-Jan-2016 11:16
This version was contributed by Danwei Huang on 28-Sep-2016 06:54.
Page authors are: Danwei Huang. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Ann Budd
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