Pavona bronni (Haime, 1850)

Baron-Szabo, Rosemarie C., 2008, Dendrophylliina, Caryophylliina, Fungiina, Microsolenina, and Stylinina, Zootaxa 1952, pp. 1-244 : 128-129

Pavona bronni (Haime, 1850)

Text-Fig. 26

v*1850 Hydnophora Bronni: Haime , in Bellardi, p. 229 (topotypes studied).

v1856 Monticularia venusta: Catullo , p. 76, pl. 17, figs 2a–b (topotypes studied).

1873 Thamnastrea Brevipes : Stoliczka, p. 42, pl. 9, figs 2–3.

1880 Reussastraea grandis, Duncan : Duncan, p. 45, pl. 10, figs 1–4.

1914 Thamnastraea brevipes Stoliczka 1873 : Felix, pars 7, p. 195.

1921 Mycetoseris minuta n. f.: Prever, p. 72, pl. 10, figs 5–6.

1925 Pavonia grandis Duncan sp. 1880: Felix, pars 28, p. 129.

v1973 Hydnophora venusta (Catullo) 1856 : Barta-Calmus, p. 303, pl. 20, figs 1–6..

v1980 Pavona bronni (Haime, 1850) : Pfister, p. 58, pl. 2, figs 1–5, pl. 3, figs 5–8 (older synonyms cited therein). non1995 Fungiastrea ? brevipes ( Stoliczka 1873) : Löser & Raeder, p. 48.

2002 Fungiastrea brevipes ( Stoliczka, 1873) : Baron-Szabo, p. 147.

Dimensions. d= 5–8 mm, in areas of intense budding the distance is around 3 mm; s=24 to up to around 30, around 18 in juvenile corallites; s/mm=5–8/5.

Description. Thamnasterioid colony, corallites irregularly disposed over surface; corallites circumscribed, appear cerioid; costosepta, generally 6–12 of which reach corallite centre, are equal or irregularly alternate in length and thickness; columella often formed by only one papilla, appearing sublamellar or irregularly styliform.

Remarks. For over a century the taxonomic position of Thamnastrea brevipes from the Maastrichtian of India as originally proposed by Stoliczka was accepted. In 1995, Löser & Raeder tentatively grouped this taxon with the genus Fungiastrea . However, the apparent presence of costae as well as thick and very coarsely granulated septa of the agariciid type exclude the species T. brevipes from both genera. In addition to these features, in showing compact to subcompact septa that are confluent or nonconfluent, and corallites that are in thamnasterioid to submeandroid arrangement, the Indian material closely corresponds to the genus Pavona .

Text-Fig. 26 Pavona bronni (Haime, 1850) . A, B, topotype, MPUR 3477, Oligocene of Italy; A, upper surface, scale bar: 4 mm; B, close-up, scale bar: 7 mm; C, sketch of upper surface of colony as figured in Duncan (1880), as type material of Reussastraea grandis , Upper Paleocene of Pakistan, scale bar: 8 mm; D, E, illustrations of upper surface view of colony as figured in Stoliczka (1873, as holotype of Thamnastraea brevipes Stoliczka, 1873 ), Maastrichtian of India; D, scale bar: 14 mm; E, scale bar: 8 mm.

Pfister (1980, p. 58–60) studied around 150 specimens of Pavona bronni (Haime, 1850) including type material and material collections from the Oligocene of Italy. She came to the conclusion that the species P. bronni was characterized by an extremely wide range of variation regarding the dimensions of its skeletal structures such as collines, polyp integration (cerioid, hydnophoroid, meandroid, sometimes circumorally arranged), septal thickness, corallite diameter, number of septa in each corallite, septal density in meandroid/ hydnophoroid series, frequency regarding the occurrence of individual corallites vs. corallites arranged in meandroid series, and a very variably developed columella (spongy, papillose, sublamellar, consisting of only one papilla, etc), the latter of which, in general, is rudimentary at the upper surface. Based on this material, Pfister could show that in many specimens several sets of characteristics co-occurred, each of which had been used to define individual species. Therefore, she taxonomically united these forms with Pavona bronni but grouped them in 5 morphological categories, which form a continuous series with Pavona bronni forma a (= Pavona minuta [ Prever, 1921]) on one end and Pavona bronni forma e (= Monitcularia venusta Catullo, 1856 ) on the other. The specimens presented here (Fig. 26) closely correspond to the morphology and range of variation of Pavona bronni : the specimens in Fig. 26 A and B (= Pavona bronni [Haime, 1850]) and the specimen in Fig. 26 C (= Reussastraea grandis Duncan, 1880 ) correspond to Pavona bronni forma b, whereas the specimen in Fig. 26 D and E (= Thamnastrea brevipes Stoliczka, 1873 ) corresponds to Pavona bronni forma a. Therefore, these species are considered synonymous.

Type locality of species. Oligocene of Italy (Castelgomberto) .

Distribution. Maastrichtian of India (Arrialoor Group), Upper Paleocene of Pakistan, Eocene of northern Spain (Catalonia), Oligocene of Italy.