Coral reef terraces are investigated in five localities around Marsa Alam on the Egyptian Red Sea Coast. The reefal limestones and the alternating terrigenous clastics are assigned to the Pleistocene Samadai Formation. Sixty-one scleractinian coral species belonging to 25 genera and 10 families were identified. Thirteen scleractinian species, for the first time recorded from the Egyptian Red Sea coastal plain, are systematically studied. The stratigraphic distribution of these fossils is illustrated and discussed. Six species are extended to the Miocene and five other species are recorded from the Pliocene and still living in the present Red Sea and the Indo-Pacific. The geographic distributions of the identified coral species are illustrated on maps. These maps show that, all the identified coral species are distributed only throughout the Indo-Pacific realm, increasing from the central part westwards across the Indian Ocean to the Red Sea. There are four species that are restricted to the Red Sea, Arabian region and West Indian Ocean.
The study area lies along the Red Sea coastal plain between latitudes 24°30′ and 25°30′N in the Marsa Alam area, forming a strip that stretches 95 km along the coast and ranging in width from 1 to 6 km. The area is covered by Miocene and younger deposits with conspicuously raised coral reef terraces of Pleistocene age which run parallel to the shore line in a discontinuous pattern and at different elevations (Fig. 1). The Pleistocene succession is represented mostly by conglomerates that grade laterally or vertically into reefal limestones usually referred to as the Samadai Formation of Philobbos et al. (1989), which is conformably overlain by the Pleistocene raised beaches and coral reefs. The present study extends using the Samadai Formation to include the overlying raised beaches and coral reefs, as there is no remarkable lithological difference between them and it is rather difficult to separate them on maps. The studied succession overlies unconformably the Pliocene Shagra Formation or the Miocene Samh Formation (Fig. 2).
The aim of the present work is to shed more light on the systematics and palaeobiogeography of the scleractinian corals building the Pleistocene succession in the Marsa Alam area. To carry out this study, five stratigraphic successions have been investigated, measured and sampled. The selected localities include Wadi Abu Dabbab and Wadi Asalay (north of Marsa Alam) and Wadi Samadai, Sharm El-Fuquiri and Sharm El-Luli (south of Marsa Alam). The Pleistocene succession in the area varies in thickness from about 33 m at Sharm El-Luli, to about 23 m at Wadi Abu Dabbab (Fig. 2). An average thickness of about 27 m is recorded around Marsa Alam City. About 100 rock samples and 550 coral specimens were collected and studied in detail. All the collected sources are deposited at the Geology Department, Faculty of Science, Mansoura University, Mansoura, Egypt.
The Pleistocene macrofauna of the Red Sea Coast have been considered as a rich material for many paleontological studies, e.g., Hassan et al. (1975), Al-Rifaiy and Cherif (1989), Ziko et al. (1993a, b), El-Sorogy (1997), Gameil (1998), Kora and Abdel-Fattah (2000), El-Sorogy (2002), Abd El-Wahab and El-Sorogy (2003) and El-Sorogy (2008). Geochronological, age dating and isotopic composition investigations for the Pleistocene-emerged coral reef terraces have been done by many workers, e.g., Gvirtzman et al. (1992), El Moursi et al. (1994), Strasser and Strohmenger (1997) and El-Asmar (1997). However, Plaziat et al. (2008) reviewed the dating of reefs on the coasts of the Red Sea including those of Egypt, Jordan, Sudan, Eritrea, Saudi Arabia and Djibouti and suggested a revision of dating of corals supposedly younger or older than the age assigned to the high-level isotopic substage MIS 5.5 (=5e).
The terminology, systematic classification and the criteria of identification of the encountered coral fossils are generally in accordance with Wells (1956), Scheer and Pillai (1983), Sheppard and Sheppard (1991) and Veron (2000a, b, c), but taking into consideration the modern prospectives on cnidarian diversity proposed by Daly et al. (2007), Glynn et al. (2007), Benzoni et al. (2007, 2011), etc. The description of the corallite wall and septal microstructure used is based on the work of Budd and Stolarski (2011). The Coral ID online version prepared by Veron and Stafford-Smith (2011) is also used to check out the identifications.
The present study led to the recognition of 61 scleractinian coral species, representing about 53 % from the previously recorded Pleistocene corals along the Egyptian Red Sea Coast reaching 116 species, belonging to 10 families (Table 1). Thirteen species namely Acropora stoddarti, A. spicifera, A. squarrosa, Stylophora wellsi, Pseudosiderastrea tayamai, Psammocora haimeana, Favites chinensis, F. vasta, Plesiastrea devantieri, Leptastrea purpurea, L. pruinosa, Echinopora hirsutissima and Porites lobata are described here for the first time from the Pleistocene Samadai Formation including the raised reefs along the Egyptian Red Sea Coast. Moreover, Acropora stoddarti and Plesiastrea devantieri are described here for the first time from the Red Sea in the fossil and living coral records. A systematic description for the newly recorded corals is summarized below.
2004 Acropora stoddarti Pillai & Scheer.—Edward et al.: 17.
Material. Two specimens collected from the southern side of Wadi Sharm El-Fuquiri (Sh.F 3-b2) and from Wadi Samadai (TI, S 18-2).
Description. Main branches of the corallum prostrate and coalescent to form a flattened solid plate with oval spaces. Corallites are immersed, occasionally sub-immersed to appressed tubular with rounded openings. On the upper surface, radials are more crowded, while those of the lower surface are widely spaced. They are 2–2.5 mm in outer diameter and 0.5–1 mm in inner calice diameter. Coenosteum is echinulate and porous.
Geographic distribution. Seychelles, Maldives, Houtman Abrolhos Islands on the west coast of Australia (Veron 1986, 2000a) and Gulf of Mannar southeast India (Edward et al. 2004).
Material. Two specimens collected from the Pleistocene Samadai Formation at Wadi Samadai and Wadi Sharm El-Luli (S 17-10 and Sh.L 5-12).
Description. Colonies are small with 5–9 mm thick anastomosing, tapering branches with blunt or rounded tips. Axial corallites are distinct but not exsert. Radial corallites are nariform with rounded openings; occasionally sub-immersed to immersed. Inner calice diameters of radials are 0.7–1 mm, while those of axial corallites are about 1 mm. Coenosteum is reticulate with spinules. Walls are synapticulothecate.
Geographic distribution. Red Sea, Malaysia, Singapore, South China Sea, Japan, Papua New Guinea, Marshall Islands and Fiji (Wallace 1999), Houtman Abrolhos Islands, south-west Australia (Veron 2000a).
Habitat Acropora spicifera (Dana) is found on reef slopes (Veron 2000a).
Material. Only one ramose corallum, collected from the Pleistocene raised reefs at the northern side of Marsa Samadai (T III, S 20-15).
Description. The main branch is 1.5 cm thick and up to 7 cm long. Branchlets are up to 0.5 cm thick and 1.5 cm long. Axial corallites are dome-shaped with thick rounded walls, 2–3 mm in average diameter, very small calice openings (0.5 mm), 1.5–2 mm exsert. Radials are 1.5 mm in outer diameter, 2–4 mm long. They are narifom with rostrate development or thick lip and rounded small openings.
Geographic distribution. Red Sea, Seychelles, Maldives, Philippines, Great Barrier Reef, Murray Islands, Marshall Islands, Tahiti (Scheer and Pillai 1983).
Habitat. The species is common in sheltered water between 5 and 25 m (Sheppard and Sheppard 1991).
Material. One well-preserved corallum collected from the Pleistocene Samadai Formation at Wadi Abu Dabbab (Ad 25-a 7).
Description. Branches are short, knobby and thick (up to 3 cm thick). Calices are closely spaced, 0.6–0.1 mm in diameter. They contain 12 septa, arranged in two cycles; six primary septa are short or fused with the columellae, the other six are rudimentary. Columellae are styliform. Coenosteum is spiny. Calices are leveled with the coenosteum and there are no hoods.
Remark. S. wellsi Scheer is clearly distinguished from other Stylophora spp. by its short, knobby, thick and blunt ended branches.
Geographic distribution. S. wellsi is common in the northern and central parts and less so in the southern parts (Sheppard and Sheppard 1991), it is also recorded from Madagascar (Veron 2000b).
Habitat. S. wellsi Scheer grows only in very shallow water exposed to strong swell and wave action. It is very rare below 3 m deep (Sheppard and Sheppard 1991; Veron 2000b).
Material. Four moderately well-preserved coralla collected from the Pleistocene Samadai Formation at Sharm El-Fuquiri (Sh.F 3b-1) and Sharm El-Luli (Sh.L 5-4) and from the raised reefs (TI) at Wadi Abu Dabbab (Ad 26-7) and Wadi Sharm El-Luli (Sh.L 7-b 5).
Description. Coralla are encrusting to sub-massive. Corallites are cerioid, polygonal, usually elongated, monocentric and 2.5–5 mm in diameter. Septa are up to 32 per calice. Columellae consist of several pinnules. Interseptal dissepiments are narrow, thin, have various shapes from convex sub-horizontal to slightly concave, vesicular dissepiments also exist.
Geographic distribution. Arabian Gulf, Arabian Sea (Sheppard and Sheppard 1991), Bali in Indonesia, Great Barrier Reef of Australia, Papua New Guinea and Maldive Islands (Veron 2000b), Western Indian Ocean, Gulf of Kutch, Gulf of Mannar, west coast of Kerala, Andamans, Celebes, Aru Island (Pillai and Patel 1988), Madagascar, Singapore, Philippines (Veron and Pichon 1980).
Habitat. According to Sheppard and Sheppard (1991); this species is fairly common in shallow sheltered water of reef slopes.
2007 Psammocora profundicella Gardiner.—Benzoni et al.- 40, fig. 2.
Material. One moderately well-preserved small corallum (up to 6 cm long and 5 cm spread), collected from the Pleistocene Samadai Formation at Wadi Sharm El-Fuquiri (Sh.F 3-b 19).
Description. Corallum is sub-massive with uneven surface. Corallites are polygonal, 2–3 mm in diameter; they are either single or arranged in short series (up to 4 calices per series). Petaloid septo-costae are inconspicuous. Up to 12 septa reach the columella and they ramify at the collines. Corallite walls have on its both sides two rows of synapticulae connecting the septo-costae.
Remarks. According to Sheppard and Sheppard (1991) in their extensive study on a large collection of specimens that collected from the Red Sea and Arabian Gulf; P. nierstraszi, P. profundicella and P. superficialis are junior synonyms of P. haimeana. The present specimen differs from P. haimeana and P. superficialis of Veron (2000b) in that the petaloid septo-costae are inconspicuous rather than that of Veron (2000b) where the primary septo-costae are distinctly petaloid. The present specimen has corallites shallower than those of P. haimeana; it matches with P. profundicella of Veron (2000b).
Geographic distribution. Red Sea, Arabian Gulf and Arabian Sea (Sheppard and Sheppard 1991), Seychelles, South Africa, Lakshadweep, Cocos-Keeling Islands, Java, Great Barrier Reef, Solomon Islands, Marshall Islands, Funafuti, Cook Islands and Tahiti (Scheer and Pillai 1983), Maldive Islands, Ashmore Reef of Western Australia, Guam, Scott Reef in Western Australia, Ryukyu Islands in Japan, Papua New Guinea and Negros in Philippines (Veron 2000b).
Habitat. It is very common and abundant species at depths from 8 to 30 m on reefs with clear or even moderately turbid water, such as the central barrier reefs and exposed fringing reefs (Sheppard and Sheppard 1991).
Material. Two specimens collected from the Pleistocene Samadai Formation at Wadi Samadai (S 17-2) and from the Pleistocene raised reefs at Wadi Abu Dabbab (T I), Ad 26-6.
Description. Coralla are massive. Corallites are cerioid, polygonal, angular, 5–13 mm in diameter. Walls are thin (0.5 mm thick). Endothecal dissepiments exist. Septa are 30–62 in number per calice according to its diameter. They are arranged in two orders. Paliform lobes are formed in some calices but inconspicuous. Columellae are trabecular. Walls are parathecal.
Remark. Favites chinensis (Verrill) is close to F. abdita (Ellis & Solander) but is distinguished by having smaller corallites which are usually angular, with fewer septa and (less reliably) fewer but more elongated septal dentations (Veron et al. 1977).
Geographic distribution. Red Sea, Arabian Gulf and Arabian Sea (Sheppard and Sheppard 1991), recorded from Ceylon, Indonesia, Japan, New Caledonia and the Great Barrier Reef (Veron et al. 1977), Calamian Islands (Veron 2000c).
Habitat. This species is a hardy one which is common on reef flats. It is especially common in pockets and depressions on the reef flat, but appears to require good water movement as it is much less common nearer back reef slopes of offshore reefs than on fore-reef crests (Sheppard and Sheppard 1991).
2000c Favites vasta (Klunzinger).—Veron 3: 152, figs. 1–5.
Material. Three large colonial parts, collected from the Pleistocene raised reefs at Sharm El-Luli, T I, Sh.L 7-b (10, 11, 12).
Description. Coralla are massive with well-developed epitheca at the lower surface. Corallites are cerioid, polygonal and angular in shape, 10–25 mm in long calice diameter, deep (up to 8.5 mm). Walls are thick (up to 3.5 mm thick). Up to 65 septa per calice according to its size are arranged in two orders. Endothecal dissepiments are prominent. Walls are septothecal.
Remarks. According to Veron (2000c); this species was incorrectly synonymized with Favites flexuosa by Veron et al. (1977), Scheer and Pillai (1983) and Sheppard and Sheppard (1991).
Geographic distribution. Red Sea (Klunzinger 1879), Papua New Guinea, Pemba Island and Zanzibar in Tanzania, Great Barrier Reef (Veron 2000c).
2011 Plesiastrea devantieri Veron.—Benzoni et al.: 235, figs. 1C, 2C.
Material. Two specimens collected from the Pleistocene raised reefs at Sharm El-Luli, TI, (Sh.L 7-b 6, 9).
Description. Coralla are massive. Corallites are rounded, plocoid, 2.5–5 mm in diameter. Both intra- and extratentacular budding exist. Up to 30 septa per calice are arranged in three orders; only septa of the first order (6–8 septa) reach the axis forming pali. Coenosteum is vesicular. Columellae are poorly developed. Walls are septothecal. Dissepiments are vesicular.
Geographic distribution. Recorded only from Socotra in the Gulf of Aden and Madagascar (Veron 2002).
Habitat. Shallow reef environments, especially lagoons (Veron 2002).
2004 Leptastrea purpurea (Dana).—Edward et al.: 56.
2007 Leptastrea purpurea (Dana).—Glynn et al.: fig. 8G.
Material. Two well-preserved coralla (S 19-5, 6), collected from the Pleistocene raised reefs (T II) at Wadi Samadai.
Description. Coralla are small and incrusting. Corallites are angular, cerioid to sub-cerioid, discrete, 2–6.5 mm inner calice diameter. Wall thickened (1–2 mm) with intercorallite groove in the middle. There are 30–60 septa per calice depending on its width. Primary septa are the thickest and the longest, they drop vertically to reach the columella and form Paliform lobes.
Remark. This study follows Wijsman-Best (1980) and Scheer and Pillai (1983) in listing Leptastrea ehrenbergana Milne-Edwards & Haime that was recorded by Klunzinger (1879b) from the Red Sea as a synonym of Leptastrea purpurea (Dana).
Geographic distribution. Widespread from Red Sea to Hawaii (Scheer and Pillai 1983), Arabian Sea and Arabian Gulf (Sheppard and Sheppard 1991), Great Barrier Reef and Ashmore Reef in Australia (Veron 2000c), Samoa and Fiji islands (Hoffmeister 1925).
Habitat. This species is found on reefs subject to strong wave action, to fairly deep sheltered water (Sheppard and Sheppard 1991). Frick and Schuhmacher (1983) recoded it from the northern Red Sea, Sinai coast at depths ranging from 2 to 82 m.
Material. Two small parts of moderately well-preserved encrusting coralla (Sh.L 5-1, 2), are collected from the Pleistocene Samadai Formation at Wadi Sharm El-Fuquiri.
Description. Coralla are small and incrusting, with angular, cerioid and discrete corallites. Corallites are 2–6 mm in diameter. Calices are relatively shallow with 35–50 septa arranged mostly in four cycles. The first two cycles are hard to separate, reach the columellae centers and form paliform lobes. Septa of the third and the forth cycles are shorter. Columella composed of several pinnules.
Geographic distribution. This species does not have a wide distribution; it is only recorded in the Indonesian Archipelago, Great Barrier Reef of Australia and New Caledonia (Wijsman-best 1980) and Calamian Islands in Philippines, Ryukyu Islands in Japan, Guam, Vanuatu and Sinai Peninsula in Egypt (Veron 2000c).
Habitat. This species is found in shallow clear water (Veron 2000c).
Material. Two incomplete well-preserved specimens, Sh.L 9-1 and Sh.L 9-2, collected from the Pleistocene raised reefs at Sharm El-Luli, T III.
Description. Coralla are sub-massive to laminar with a well-developed epitheca on the lower surface. Corallites are 5–7.5 mm in diameter, plocoid, rounded, conical or cylindrical with thick walls (1.5–2 mm). They are highly exsert over the theca (up to 7.5 mm). Spiny exothecal costae are well developed. There are 23–30 septa in each calice. Walls are septothecal. Exothecal vesicular dissepiments are abundant.
Remark. Echinopora hirsutissima Milne-Edwards & Haime is almost similar to E. gemmacea (Lamarck), but the latter has smaller corallites and less coarse structures. Exothecal costae in E. hirsutissima are more beaded and spiny than any other Echinopora.
Geographic distribution. Widely distributed from the Red Sea to New Caledonia (Wijsman-Best 1980), Chagos, Reunion Island and Maldives (Pillai and Scheer 1976), South-west Indian Ocean (Riegl 1996), Pemba Island and Zanzibar in Tanzania, Seychelles, Madagascar and Sinai Peninsula in Egypt (Veron 2000c).
Habitat. Exposed, shallow reef environments (Riegl 1996 and Veron 2000c).
Material. Five specimens, collected from the Pleistocene raised reefs (T II), at Wadi Sharm El-Luli (Sh.L 8).
Description. Coralla are massive, hemispherical. Corallites are polygonal, 0.8–1.2 mm in average calice diameter. All skeletal elements inside the corallites including columellae, septa, paliform lobes and the denticles are ornamented with spines. Columella is styliform and compressed in the direction of the directive septa.
Remarks. P. lobata Dana can be differentiated from P. lutea Milne-Edwards & Haime, as the former has free triplet septa, while these are fused in P. lutea Milne-Edwards & Haime. It is characterized by having distinct paliform lobes, which differentiate it from P. solida (Forskål).
Geographic distribution. Red Sea and Gulf of Aden (Sheppard and Sheppard 1991), Easter (Rapa Nui) and Sala-y-Gómez Islands (Glynn et al. 2007), Great Barrier Reef of Australia, Clipperton Atoll, eastern Pacific (Veron 2000c).
Habitat. P. lobata Dana dominates in back reef margins, lagoons and some fringing reefs (Veron 2000c).
Stratigraphic distribution and correlation
The total number of species recorded in the present work represents about 7.7 % from the living coral species recorded by Veron (2000a, b, c) from the world, reaching 793 species. On the generic level, the studied corals in the Marsa Alam area represent 25 genera compared to 34 genera previously recorded from the Egyptian Red Sea coastal plain (about 74 %). All scleractinian coral families recorded by previous workers from the Pleistocene succession along the Egyptian Red Sea Coast (12 families) are recorded here from the Marsa Alam area except for the Pectiniidae and Dendrophylliidae (Table 1). These are representing two-thirds (12/18) of the known scleractinian coral families.
The vertical distribution of these fossils is illustrated in Fig. 7, and the age ranges of the specifically identified corals, based on their previous records in/and outside Egypt, known from the available literature, are given in Fig. 8. Among the recorded coral fossils, the faviid family (27 species) is the highest in diversity (about 44 % from the total number of the recorded species) and also is the most abundant in the collected material, followed by the acroporid, fungiid and poritid families (Table 1). Stratigraphically, 24 species are recorded from the lower part of the Samadai Formation, usually referred to as the older reef, and are also present in the raised beaches and coral reefs (Fig. 7). The rest of the coral fauna is recorded from the overlying coral reef terraces, of which 13 are, restricted to the youngest Pleistocene terrace (III) and still surviving in the fringing reefs.
The stratigraphic range of the majority (50 species) of the identified species which have been previously recorded from the corals still living in the present Red Sea and the Indo-Pacific is extended down to the Pleistocene (Fig. 8). The following six species are extended to the Miocene; Stylophorapistillata (Esper), Goniastrea pectinata (Ehrenberg), Echinopora gemmacea (Lamarck) Porites solida (Forskål), Pavona sp. and Leptastrea sp. There are other five species recorded from the Pliocene and still living in the present Red Sea and the Indo-Pacific; Pseudosiderastreatayamai Yabe & Sugiyama, Hydnophoramicroconos (Lamarck), Cyphastrea serailia (Forskål), Platygyra daedalea (Ellis & Solander) and Goniastrearetiformis (Lamarck).
It is rather difficult to compare the scleractinian coral fauna of different regions due to the differences in sampling intensity and in the taxonomic interpretations of different authors. However, as far as the published data permits, a low diversity (8 species) is found in the Gabal Tanka area (Gameil 1998) and in the Gulf of Suez region (11 species; El-Sorogy 2002). The Gulf of Aqaba and Southern Sinai area yielded more diverse coral fauna, where 29 species were recorded by El-Sorogy (1997). This is followed by the Hurghada–Quseir area where 54 species were described by Ziko et al. (1993a, b), Zalat et al. (2000), and Abd El-Wahab and El-Sorogy (2003). The Marsa Alam area is higher in diversity where about 80 species were recorded (Kora and Abdel-Fattah 2000 and the present work).
During the Miocene Epoch, the closure of the Tethys Sea and the isolation of the Mediterranean Sea led to the formation of two coral faunas; the Atlantic and far eastern Pacific and that of the Indian Ocean and western Pacific. The subsequent closure of the Isthmus of Panama and the extinction of corals on both sides of the Isthmus during the Plio-Pleistocene glaciation resulted in two coral communities; the Atlantic and Indo-Pacific corals (Fig. 9a) that are almost completely different at species level (Veron 1985). According to Veron (2000a); the history of corals subsequent to the Miocene becomes decreasingly visible in the fossil record and increasingly visible in the taxonomy and distribution in living corals. Throughout the geologic history of the Red Sea, the Early Pliocene was the time of closing the connection with the Mediterranean Sea (Braithwaite 1987). The Plio-Pleistocene fauna and flora of the Red Sea are totally Indo-Pacific in affinity and origin (Kora and Abdel-Fattah 2000). Although the Red Sea was once connected with the Palaeo-Mediterranean, the great evaporation of the Miocene would have completely eliminated the Mediterranean fauna.
The geographic distributions of the identified coral species are illustrated in Figs. 9, 10, 11. This is based on the distribution maps and data published by different authors, e.g., Scheer and Pillai (1983), Veron (2000a, b, c), Sheppard and Sheppard (1991), Veron (1993), Glynn et al. (2007), etc. These maps show that all the identified coral species are distributed only throughout the Indo-Pacific realm. There are four species that are restricted to the Red Sea, Arabian region and West Indian Ocean. Stylophora wellsi Scheer is distributed in the Red Sea and Madagascar (Fig. 10a). Plesiastrea devantieri Veron has a very minor distribution; in the Gulf of Aden and Madagascar and is recorded for the first time from the Red Sea (Fig. 11d). Porites nodifera Klunzinger is only distributed within the Arabian region (Red Sea, Gulf of Aden, Arabian Sea, Gulf of Oman and Arabian Gulf). Porites columnaris Klunzinger is only distributed throughout the Red Sea and the Gulf of Aden (Fig. 11f). For all other species distributions, there is a general progressive decrease in the coral diversity eastwards across the Pacific, while it increases from the central Indo-Pacific westwards across the Indian Ocean to the Res Sea.
During the Pleistocene, extensive sea level fluctuations mostly at −30 to −80 m below present sea level resulted in two reef growth phases, and uplift of older fringing reefs at margins, forming terraces (Sheppard et al. 1992). Raised beaches and coral reef terraces were developed over either the reefal limestone or the conglomerates of the Samadai Formation. These reefs are characterized by fringing reef types in comparison with their living counterparts. They are missing in front of the wadi mouths where they are replaced by terrigenous sediments and gravels of alluvial fans. Throughout the present study, a staircase of three marine raised reef terraces with different altitudes from 12–17 m (TI), 5–12 m (TII) and 2–4 m (TIII) above the present sea level are recognized. The present day altitudes of these terraces are the product of eustatic sea level fluctuations combined with differential tectonic uplift (Dullo 1990, El Moursi et al. 1994).
According to Tucker (2003), the reefal facies were interbedded with terrigenous clastics that were deposited in shoreface–foreshore and fluvial environments, either contemporaneous with reefal sedimentation or during the subsequent lowstands. The reefal carbonates are mainly coral framestones composed mostly of large scleractinian coral colonies up to several meters in diameters, occasionally interbedded with fossiliferous conglomerates, sandstones and beach rocks. The conglomerates are interpreted as a series of prograding clastic beaches developed at a time of sea level stillstand. These microfacies and the faunal associations suggest deposition mainly in the organic reef buildups dissected by short-time pluvial episodes (Kora et al. 2013). Among the scleractinian corals recorded from the Pleistocene raised reefs; the faviid corals are the most dominant family with the highest diversity. They range in depth from 20 m to about 40 m (Sheppard and Sheppard 1991).
The Pleistocene raised beaches and coral reefs of the Marsa Alam area form a discontinuous strip in three morphological terraces with different altitudes ranging between 17 and 2 m above the present sea level. These terraces are included here in the underlying reefal limestones and conglomerates known as the Samadai Formation as there is no remarkable lithological difference between them. Also, it is rather difficult to separate them on maps. The Pleistocene coral-bearing succession was developed over the Miocene/Pliocene deposits after a period of uplift and truncation.
The systematic palaeontology of the encountered scleractinian corals led to the recognition of 61 scleractinian coral species belonging to 25 genera. Thirteen species including Acropora stoddarti, A. spicifera, A. squarrosa, Stylophora wellsi, Pseudosiderastrea tayamai, Psammocora haimeana, Acanthastrea hemprichii, Favites chinensis, Plesiastrea devantieri, Leptastrea purpurea, L. pruinosa, Echinopora hirsutissima and Porites lobata are systematically described here for the first time from the Pleistocene succession along the Egyptian Red Sea Coast. All scleractinian coral families recorded by previous workers from the Pliocene–Pleistocene succession along the Egyptian Red Sea Coast (12 families) are recorded here from the Marsa Alam area except for the Pectiniidae and Dendrophylliidae. These are representing two-thirds (12/18) of the known scleractinian coral families. Among the recorded coral fossils, the faviid family (27 species) is the highest in diversity (up to 44 % from the total number of species recorded) and also is the most abundant in the collected material. This is followed by the acroporid, fungiid and poritid families.
The stratigraphic distribution of these fossils is illustrated in a faunal range chart and their age ranges are also discussed and correlated with the published data. The stratigraphic range of the majority (50 species) of the identified corals which have been previously recorded from the corals still living in the present Red Sea and the Indo-Pacific is extended down to the Pleistocene. Only six species are extended to the Miocene and five species recorded from the Pliocene and still living in the present Red Sea and the Indo-Pacific.
The geographic distribution of the identified corals is illustrated on maps. All the identified coral species are distributed only throughout the Indo-Pacific realm. Four species are restricted to the Red Sea, Arabian region and West Indian Ocean: Stylophora wellsi is distributed in the Red Sea and Madagascar; Plesiastrea devantieri has a very minor distribution in the Gulf of Aden and Madagascar and is recorded here for the first time from the Red Sea; Porites nodifera is only distributed within the Arabian region (Red Sea, Gulf of Aden, Arabian Sea, Gulf of Oman and Arabian Gulf) whereas Porites columnaris is distributed throughout the Red Sea and the Gulf of Aden. For all other species distributions, there is a general progressive decrease in the coral diversity eastwards into the Pacific, while it increases from the central Indo-Pacific westwards across the Indian Ocean to the Red Sea.
Abd El-Wahab, M., & El-Sorogy, A. S. (2003). Scleractinian corals as pollution indicators, Red Sea coast, Egypt. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte,11, 641–655.
Al-Rifaiy, I. A., & Cherif, O. H. (1989). Paleogeographic significance of Pliocene and Pleistocene mega-invertebrates of the Red Sea and the Gulf of Aqaba. Journal University Kuwait (Science),16(2), 367–399.
Benzoni, F., Stefani, F., Stolarski, J., Pichon, M., Mitta, G., & Galli, P. (2007). Debating phylogenetic relationships of the scleractinian Psammocora: molecular and morphological evidences. Contributions to Zoology,76(1), 35–54.
Conoco-EGPC. (1987). Geological map of Egypt-NG 36 SE Gabal Hamata. Scale 1: 500 000. In E. Klitzsch, F. List & G. Pöhlmann. Cairo: Coral and the Egyptian General Petroleum Corporation.
Daly, M., Brugler, M. R., Cartwright, P., Collins, G. A., Dawson, M. N., Fautin, D. G., et al. (2007). The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus. Zootaxa,1668, 127–182.
Edward, J.K.P., Patterson, J., Venkatesh, M., Mathews, G., Chellaram, C. & Wilhelmsson, D. (2004). A field guide to stony corals (Scleractinia) of Tuticorin in Gulf of Mannar, Southeast coast of India. In Suganthib Devadason Marine Research Institute (SDMRI) (p. 85). Special research publication no. 4.
El Moursi, M., Hoang, C. T., El-Fayoumy, I. F., Hegab, O., & Faure, H. (1994). Pleistocene evolution of the Red Sea coastal plain, Egypt: Evidence from uranium-series dating of emerged reef terraces. Quaternary Science Reviews,13, 345–359.
El-Akkad, S., & Dardir, A. (1966). Geology of the Red Sea coast between Ras Shagra and Marsa Alam with short notes on the exploratory work at Gebel El- Rusas lead-zinc deposits. Geologic Survey Egypt,35, 1–67.
El-Sorogy, A. S. (1997). Pleistocene coral reefs of southern Sinai, Egypt: Fossil record, facies and diagenetic alterations. Middle East Research Center Ain Shams University, Earth Science Series,11, 17–36.
El-Sorogy, A. S. (2002). Palaeontology and depositional environments of the Pleistocene coral reefs of the Gulf of Suez, Egypt. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen,225(3), 337–371.
Glynn, P. W., Wellington, G. M., Riegl, B., Olson, D. B., Broneman, E., & Wieters, E. A. (2007). Diversity and biogeography of the scleractinian coral fauna of Easter Island (Rapa Nui). Pacific Science,61(1), 67–90.
Kora, M., Ayyad, S., & El-Desouky, H. (2013). Microfacies and environmental interpretation of the Pliocene-Pleistocene carbonates in the Marsa Alam area, Red Sea coastal plain, Egypt. Journal of environmental sciences, Mansoura University,42(1), 155–182.
Nothdurft, L. D., & Webb, G. E. (2007). Microstructure of common reef-building coral genera Acropora, Pocillopora, Goniastrea and Porites: constrains on spatial resolution in geochemical sampling. Facies,53, 1–26.
Philobbos, E. R., El-Haddad, A. A., & Mahran, T. M. (1989). Sedimentology of syn—rift Upper Miocene (?)—Pliocene sediments of the Red Sea area: a model from the environs of Marsa Alam, Egypt. Egyptian Journal Geology,33(1–2), 201–227.
Plaziat, J.-C., Reyss, J.-L., Choukri, A. & Cazala, C. (2008). Diagenetic rejuvenation of raised coral reefs and precision of dating. The contribution of the Red Sea reefs to the question of reliability of the Uranium-series datings of Middle to Late Pleistocene key-reef terraces of the world.- Carnets de Geologie/Notebooks on Geology, Brest, Article 2008/04 (CG2008_A04).
Riegl, B. (1996). Corals of the South-west Indian Ocean, IV. The hard coral family Faviidae GREGOY 1900 (Scleractinia: Faviina). Investment Report Oceanographic Research Institute,70, 1–47.
Veron, J.E.N. (1993). A biogeographic database of hermatypic corals: species of the central Indo-Pacific, genera of the world (Vol. 10, p. 433). Australian Institute of Marine Science Monograph Series.
Veron, J.E.N. (2000a). Corals of the world. In M. Stafford-Smith (Ed.) Townsville (Vol. 1, p. 463). Australia: Australian Institute of Marine Science.
Veron, J.E.N. (2000b). Corals of the world. In M. Stafford-Smith (Ed.). Townsville (Vol. 2, p. 429). Australia: Australian Institute of Marine Science.
Veron, J.E.N. (2000c). Corals of the world. In M. Stafford-Smith (Ed.) Townsville (Vol. 3, p. 490). Australia: Australian Institute of Marine Science.
Veron, J.E.N. (2002). New species described in corals of the world. Monograph Series 11 (p. 207). Australian Institute of Marine Science.
Veron, J.E.N. & Pichon, M. (1980). Scleractinia of Eastern Australia, Part III: Families Agariciidae, Siderastreidae, Fungiidae, Oculinidae, Merulinidae, Mussidae, Pectiniidae. Monograph Series 4 (p. 422). Australian Institute of Marine Science.
Veron, J.E.N. & Pichon, M. (1982). Scleractinia of Eastern Australia, Part IV: Family Poritidae. Monograph Series 5 (p. 159). Australian Institute of Marine Science.
Veron, J.E.N., Pichon, M. & Wijsman-Best, M. (1977). Scleractinia of Eastern Australia, Part II. Families Faviidae, Trachyphylliidae. Monograph Series 3 (p. 233). Australian Institute of Marine Science.
Veron, J.E.N. & Stafford-Smith, M.G. (2011). Coral ID. www.coralid.com version 1.1. Australian Institute Marine Science.
Wallace, C. C. (1999). Staghorn Corals of the World: A Revision of the Genus Acropora (Scleractinia, Astrocoeniina, Acroporidae), worldwide, with emphasis on morphology, phylogeny and biogeography. Melbourne: CSIRO. 422 pp.
Wells, J.W. (1956). Scleractinia. In Moore, R.C. (Ed.), Treatise on Invertebrate Paleontology, Part F: Coelenterata (pp. F328–444). Geological Society of America and University of Kansas press.
Wijsman-Best, M. (1980). Indo-Pacific coral species belonging to the subfamily Montastreinae VAUGHAN & WELLS, 1943 (Scleractinia-Coelenterata) part II. The Genera Cyphastrea, Leptastrea, Echinopora and Diploastrea. Zoologische Mededelingen, Rijksmuseum van Natuurlijke Historie, Leiden 55(21), 235–263.
Zalat, A., Hamza, F., Ziko, A., & El-Sorogy, A. S. (2000). Scleractinian corals (Suborder Faviina) of the Pleistocene coral reefs in the area between Hurghada and Quseir, Red Sea coast. Egypt. Egyptian Journal of Geology,44(1), 237–255.
Ziko, A., Hamza, F. & El-Sorogy, A.S. (1993). Non molluscan macrofauna of the Pliocene—Quaternary sequence in Quseir area, Red Sea coast, Egypt. Bulletin of the Faculty of Science,Mansoura University, Symposium of the Quaternary & Development in Egypt (pp. 237–274).
Ziko, A., Hamza, F., Zalat, A., & El-Sorogy, A. S. (1993b). Scleractinian corals (Suborder Fungiina) of the Pleistocene raised reefs in the area between Hurghada and Quseir, Red Sea coast, Egypt. Bulletin of the Faculty of Science, Ain Shams University,31, 325–341.