Unusual shallow water Devonian coral community from Queensland and its recent analogues from the inshore Great Barrier Reef

Abstract

Palaeozoic coral communities were dominated by two extinct coral groups: Tabulata and Rugosa. Whilst they are not closely related to modern Scleractinia, they are morphologically convergent, displaying many morphological characters that allow comparisons between recent and ancient coral reef communities. The extensive shallow-water reef communities of the Devonian were generally dominated by stromatoporoid sponges, with corals occupying deeper environments. Here, we describe an unusual, shallow water coral reef community from the Middle Devonian (Givetian, approx. 385 Ma) of the Fanning River area, Queensland, Australia. The coral community is dominated by tabulate corals, but also includes solitary and occasionally colonial rugose corals. Tabulate corals most commonly exhibit foliose and massive morphologies, but encrusting and branching growth forms also occur. The depositional environment was characterized by a shallow water depth, moderate hydrodynamic energy, high sedimentation rate, and high turbidity. Since these environmental factors influence the morphological composition of modern coral communities, we hypothesize that similar environments may result in morphologically equivalent coral assemblages throughout the Phanerozoic. To test this idea, we qualitatively compare the Fanning River reefs with modern scleractinian coral assemblages in a similar environmental setting at Magnetic Island. Both reefs are located in a shallow water less than 10 m deep, with high sediment flux, moderate wave energy, and generally high turbidity. Like Fanning River, Magnetic Island coral communities are dominated by foliose morphologies, with contributions from massive and branching forms. The Fanning River reef, together with previously identified Silurian and Devonian mesophotic coral ecosystems, suggest that Palaeozoic coral assemblages may share many functional characteristics with modern scleractinian reefs in similar environments. Therefore, the geological record of inshore, high turbidity-adapted coral communities can be traced back as far as 385 Ma.

Middle Devonian ostracods from the Naidaijin Formation, Kurosegawa belt, Kyushu, Japan: Paleoecological and paleogeographical significance

“…The fauna of the Lower Huaning Formation is characterized by rugose corals, Dendrostella trigemme and Alveolitella (Zhang & Pojeta Jr., 1986). These rugose corals have been reported from the Middle Devonian inshore environment (Zapalski et al, 2021), indicating that C. yongshengensis also lived in an inshore environment.…”

“…The fauna of the Lower Huaning Formation is characterized by rugose corals, Dendrostella trigemme and Alveolitella(Zhang & Pojeta Jr., 1986). These rugose corals have been reported from the Middle Devonian inshore environment(Zapalski et al, 2021), indicating that C. yongshengensis also lived in an inshore environment.Thus, nearshore ostracod taxa demonstrate strong evidence of a linkage between the South China and the Kurosegawa belt of Kyushu Tanaka et al (2019). reported Lower Devonian shallow marine ostracods from the Fukuji Formation of the Hida Gaien belt of central Japan.…”

Rare earth element geochemistry of Middle Devonian reefal limestones of the Dianqiangui Basin, South China: implications for nutrient sources and expansion of the reef ecosystem

“…Widespread platy growth habits of tabulate corals, stromatoporoids, and chaetetids in the Jiwozhai reef biota indicated that they lived in light-limited environments ( Huang et al, 2020 ). The platy morphology of the Givetian reef biota also developed in other parts of Dianqiangui Basin ( Liu et al, 2003 ) and the southern shelf of Laurussia at tropical latitudes ( Zapalski et al, 2021 ). The Jiwozhai reef, together with other Givetian reef ecosystems at tropic latitudes, suggests that Givetian reef biota share functional characteristics with modern scleractinian-dominated turbid-water assemblage.…”

“…, quartz and illite) in the reefal limestone and a greater biodiversity than the Buzhai reef ( Liu et al, 2004 ; Huang et al, 2020 ) suggests that reef-building was sustained by continental runoff. It is noteworthy that a coral community dominated by tabulate and rugose coral described from the Fanning River area of Queensland, Australia, appears to have thrived in shallow turbid water during Givetian time ( Zapalski et al, 2021 ). It appears that turbid-water reefs were not unusual during the Givetian time.…”

Colonial coral resilience by decreasing size: reaction to increased detrital influx during onset of the late Palaeozoic Ice Age

“…The latter is significantly lower in dark environments [26]. Therefore, increased terrestrial sediment influx due to continental weathering is expected to have important (paleo)ecological consequences [4,6,27]. In modern marine systems, scleractinian reef coral species display high phenotypic plasticity in skeletal morphology under terrestrial sediment influence and/or light attenuation, such as coral colony flattening [26][27][28][29].…”