Origin and Paleoecology of Maastrichtian Rockground and Chalk Facies in Southcentral Alabama

Bryan, Jonathan R.

doi:10.2307/3514796

Cited by 19 publications

(16 citation statements)

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“…4) and occurrence within non-hardground-type deposits (shell beds) indicate that the majority of the cobbles studied (especially those of smaller sizes) must have been transported, colonized by cementing biotas and periodically overturned. Thus, the cobbles have all the characteristics of a mobile rockground (e.g., Wilson, 1985Wilson, , 1987Bryan, 1992;Plint et al, 2006). Periodic overturning is not only evidenced by encrustation on all sides, but also in the abraded skeletons of the encrusters.…”

Section: Origin Of the Cobblesmentioning

confidence: 98%

Microconchid-dominated cobbles from the Upper Devonian of Russia: Opportunism and dominance in a restricted environment following the Frasnian–Famennian biotic crisis

Zatoń

Журавлев²,

Rakociński

et al. 2014

Palaeogeography, Palaeoclimatology, Palaeoecology

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Section: Origin Of the Cobblesmentioning

confidence: 98%

Microconchid-dominated cobbles from the Upper Devonian of Russia: Opportunism and dominance in a restricted environment following the Frasnian–Famennian biotic crisis

Zatoń

Журавлев²,

Rakociński

et al. 2014

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…The encrusting fauna (there are no borings) is diverse and abundant. Like the Prairie Bluff cobbles of Bryan (1992), the encrusters are found in distinct zones, indicating that the clasts were no longer moving after they were colonised. The enclosing transgressive sediments suggest that these cobbles and boulders, like their Prairie Bluff counterparts, were occupied in considerably lower energy waters than the Qahlah clasts.…”

Section: O M P a R I S O N S W I T H O T H E R H A R D S U B S T R mentioning

confidence: 99%

“…Such hardgrounds are normally associated with subtidal limestones, not siliciclastic sands and gravels (Wilson and Palmer 1992). Secondly, the Qahlah was deposited close to the palaeoequator, thereby providing a rare glimpse of a tropical, Cretaceous rockyshore community (sensu Johnson 1988) and permitting comparisons to be made with higher latitude communities described from elsewhere in the world (Surlyk and Christensen 1974;Wilson 1986;Bryan 1992;Zõ Âtt and Nekvasilova Â 1996;Johnson and Baarli 1999).…”

mentioning

confidence: 99%

Palaeocology of Hard Substrate Faunas from the Cretaceous Qahlah Formation of the Oman Mountains

Wilson

Taylor

2001

Palaeontology

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ABSTRACT. Skeletal encrusters and carbonate hardgrounds are rare in siliciclastic sands and gravels because of high levels of abrasion and sediment movement. An exception to this is the Maastrichtian Qahlah Formation of the Oman Mountains, a sequence of coarse siliciclastic sediments deposited on a shallow marine shelf above wavebase and at an equatorial palaeolatitude. This unit contains intercalated carbonate hardgrounds and other hard substrates which were encrusted and bored. The hard substrates, comprising carbonate and silicate clasts, calcareous bioclasts (mollusc shells and coral fragments) and wood, supported a diverse encrusting and boring fauna dominated in biomass by the oyster Acutostrea. There are twelve bryozoan species and at least two serpulid worm species, most living cryptically. Other encrusters on exposed surfaces include the agglutinated foraminiferan Placopsilina and several species of colonial corals. Borings in the carbonate clasts and shells are predominantly those of bivalves (Gastrochaenolites), with subsidiary clionid sponge (Entobia) and acrothoracican barnacle (Rogerella) borings. The woodgrounds are thoroughly bored by teredinid bivalves (Teredolites). Of the common substrate types, carbonate hardground clasts support the greatest number of taxa, followed by chert clasts, with limestone rockground pebbles being depauperate. Clast composition and relative stability probably explain these differences. Individual clasts probably had variable and typically long colonisation histories. Detailed palaeoecological interpretation is constrained by taphonomic loss, time-averaging and clast transportation and reorientation. Evidence from the Qahlah Formation shows that tropical rocky-shore biotas in the Cretaceous were not impoverished as previously believed.

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“…Most of the individuals in this taxonomic group belong to M. hoffmanni, a large species of mosasaur with cranial adaptations for feeding on large prey (Lingham-Soliar, 1995;Mulder, 1999;Harrell & Martin, 2014). Bryan (1992) (see Table 1). Gallagher (2005) reported only Mosasaurus sp.…”

Section: Discussionmentioning

confidence: 99%

Habitat preference of mosasaurs indicated by rare earth element (REE) content of fossils from the Upper Cretaceous marine deposits of Alabama, New Jersey, and South Dakota (USA)

Harrell

Pérez‐Huerta

2014

Netherlands Journal of Geosciences

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Knowledge of habitat segregation of mosasaurs has been based on lithology and faunal assemblages associated with fossil remains of mosasaurs and stable isotopes (δ13C). These approaches have sometimes provided equivocal or insufficient information and, therefore, the preference of habitat by different mosasaur taxa is still suboptimally constrained. The present study is focused on the analysis of rare earth element (REE) ratios of mosasaur fossils from the Upper Cretaceous formations of western Alabama, USA. Results of the REE analysis are used to infer the relative paleobathymetry associated with the mosasaur specimens and then to determine if certain taxonomic groups showed a preference for a particular water depth. Comparisons are then made with mosasaur specimens reported in the literature from other regions of North America from different depositional environments. Results indicate that Mosasaurus, Platecarpus and Plioplatecarpus may have preferred more restricted habitats based on water depth whereas Tylosaurus and Clidastes favoured a wider range of environments. Results also suggest that Plioplatecarpus lived in a shallower environment than its Platecarpus predecessor. Although the results of this study are encouraging, caution must be exercised before drawing any final conclusions due to the small sample size of most of the taxa analysed.

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Origin and Paleoecology of Maastrichtian Rockground and Chalk Facies in Southcentral Alabama

Cited by 19 publications

References 0 publications

Microconchid-dominated cobbles from the Upper Devonian of Russia: Opportunism and dominance in a restricted environment following the Frasnian–Famennian biotic crisis

Microconchid-dominated cobbles from the Upper Devonian of Russia: Opportunism and dominance in a restricted environment following the Frasnian–Famennian biotic crisis

Palaeocology of Hard Substrate Faunas from the Cretaceous Qahlah Formation of the Oman Mountains

Habitat preference of mosasaurs indicated by rare earth element (REE) content of fossils from the Upper Cretaceous marine deposits of Alabama, New Jersey, and South Dakota (USA)

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