Hábitos de vida da associação "Schuchertella" agassizi - Pthychopteria eschwegei, formação Maecuru, Devoniano, Bacia do Amazonas, Brasil

The fossils studied came from outcrops of the Maecuru and Curuá rivers, State of Pará, belonging to the upper strata of the Maecuru Formation, Eifelian age. In this formation, two associations of marine benthic invertebrate can be identified, each inferring a distinct paleoenvironment. The association analyzed occurs in medium and coarse sandstones and shows "Schuchertella" agassizi and Ptychopeteria eschwegei as predominant organisms. It was idnetified 12 species of brachiopods, 20 species of bivalves, 12 of trilobites, 8 of gastropods, 6 of bellerophonts, 3 of crinoids and 3 of tentaculitids in this association. Brachiopods are the most abundant organisms, responsible for approximately 50% of it, followed by tentaculitids and bivalves. Trilobites, gastropods and bellerophonts sum less than 10% of the aforementioned association. Crinoids were not included in the quantitative analysis because they are only found as calicinal plates and disarticulated column disks. The brachiopods showed, through their morphofunctional characteristics, suspension feeders recumbent (free-lying) epifaunal life habit or a pedicle attached mode of life. The bivalves showed a predominant suspension feeder semiinfaunal habit, attached by byssus threads to the substratum, and an infaunal mode of life. All the trilobites showed a predator/scavenger and vagile epifaunal habit. The epifaunal platyceratids represents the gastropods with low mobility (coprophagous/suspension feeders). The bellerophonts showed an epifaunal highly/medium mobility and grazing/predator habit. The tentaculitids having a semi-infaunal, suspension feeder habit. The suspension feeder forms (brachiopods, bivalves and tentaculitids) account for over 90% of the organisms, with the remaining percentage distributed among the predator/scavenger (trilobites), coprophagous/suspension feeders (gastropods), grazers/ predators (bellerophonts) and deposit feeders (rare bivalves). The predominance of suspension feeder forms corroborates the environment inferred for the association, since suspension feeders adapt more easily to rough waters and coarse sediments. The life habits showed adaptations concerning a shallow marine environment with agitated waters, well-oxygenated, normal salinity and moderate temperatures.

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Hábitos de vida dos Gastropoda e Bellerophontida da formação Maecuru, Devoniano Médio, Bacia do Amazonas, Brasil

Anuário do Instituto de Geociências - UFRJ ◽

10.11137/2007_1_197-203 ◽

2007 ◽

Vol 30 (1) ◽

pp. 197-203

Author(s):

Luiza Corral Martins de Oliveira Ponciano ◽

Deusana Maria da Costa Machado ◽

Ana Carolina Gelmini de Faria ◽

Ana Carolina Maciel ◽

Juliana Matos ◽

...

Keyword(s):

High Mobility ◽

The Other ◽

Nutrient Source ◽

Cross Sectional ◽

Suspension Feeders ◽

Fine Grained ◽

Mode Of Life ◽

Life Habits ◽

Shallow Seas ◽

High Diversity

The Maecuru Formation comprises the Devonian-Carboniferous sedimentary sequence of Amazonas Basin and consists of fluvialdeltaics to neritics sandstones and pelites layers. Its fossiliferous sediments (the uppermost part of the Lontra Member) consists of hummocky cross-stratified fine-grained to very coarse sandstones beds.With the purpose of adding more information about the palaeoecology of The Maecuru Formation fossils, the life habits of gastropods and bellerophontids were inferred based on functional analysis and similarities with the living forms. The more significant features used were: (1) total frontal cross-sectional area, (2) height and relative positions of pressure point and center of gravity, (3) apertural margin morphology, (4) kind of symmetry and (5) surface smoothness. The species Platyceras (Orthonychia) steinmanni; Platyceras (Tumbophalus) hartti; Platyceras (Platyostoma) darwini; Platyceras (Platyostoma) (?) agassizi; Platyceras (Orthonychia) meerwarthi; Platyceras (Orthonychia) gracilis; Platyceras (Tumbophalus) coutoanus; "Platyceras" tschernischewi; "Platyceras" subconicum; "Platyceras" (Ortonychia) hussaki; "Platyceras" (Ortonychia) whitii; "Platyceras" (Ortonychia) whitii var. curua and "Platyceras" symmetricum var. maecuruensis represent the epifaunal gastropods with low mobility (coprophagous/suspension feeders) of the Maecuru Formation, living symbiotically directly over the anus of a crinoid or nearby. This coprophagous mode of life was probably a non-obligate relationship, because only the closest organisms will get all the advantages of using the crinoid host as a nutrient source. The others adult platyceratids would have a broader feeding repertoire, like as suspension feeders. The bellerophonts Plectonotus (Plectonotus) derbyi, Plectonotus (?) (Plectonotus) salteri e Bucanella reissi would have an epifaunal medium to high mobility, showing a predator habit preferably. On the other hand Bucania freitasi, Ptomatis forbesi and Bellerophon steltzneri showed morphologies compable to a grazer habit with medium mobility. This relative high diversity of gastropods and bellerophonts corroborates the environment of medium and inner shelf inferred for the Maecuru Formation among the others macrofossils, since the majority of Paleozoic fauna of gastropods were typically from shallow seas.

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Primitive life habits and adaptive significance of the pelecypod form

Paleobiology ◽

10.1017/s0094837300004760 ◽

1976 ◽

Vol 2 (3) ◽

pp. 183-190 ◽

Cited By ~ 13

Author(s):

Michael J. S. Tevesz ◽

Peter L. McCall

Keyword(s):

Small Body ◽

Relative Size ◽

Mantle Cavity ◽

Shell Morphology ◽

Suspension Feeding ◽

Suspension Feeders ◽

Body Sizes ◽

Mode Of Life ◽

Life Habits ◽

Soft Bottoms

The typical pelecypod form, long thought to be primitively adaptive to burrowing, is likely to have been originally adaptive to a suspension feeding, epifaunal, possibly crawling mode of life. At small body size (< 1 cm), pelecypods possessing typical burrowing features can function as epifaunal crawlers. Pelecypods arose at small body sizes and are part of a molluscan evolutionary sequence in which relative size of the mantle cavity increased to accommodate a few large gills specialized for suspension feeding.Acquisition of a bivalved shell by ancestral epifaunal suspension feeders may have offered protection from sediment clogging on soft bottoms, additional control over the direction, volume, and rate of water flow through the mantle cavity, more effective protection from predators, and better short-term control of the internal environment. Consideration of invertebrate groups analogous to the pelecypods (Branchiopoda, Cladocera, Ostracoda, Phyllocarida) support the view that the bivalve condition is primarily an adaptation for suspension feeding and predator avoidance in benthic environments.The earliest known pelecypod, Fordilla troyensis Barrande, was not necessarily infaunal just because it had features similar to much larger, Recent burrowers. The size, shell morphology and environment of preservation of F. troyensis all suggest that it is reasonable to envision Cambrian pelecypods as epifaunal suspension feeders, possibly crawling on sedimentary bottoms. Moreover, the sudden Ordovician expansion of pelecypods and increase in individual size may be explained as a result of invasion of the infaunal adaptive zone.

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Macrophyte-derived detritus in shallow coastal waters contributes to suspended particulate organic matter and increases growth rates of Mytilus edulis

Marine Ecology Progress Series ◽

10.3354/meps13314 ◽

2020 ◽

Vol 644 ◽

pp. 91-103

Author(s):

D Bearham ◽

MA Vanderklift ◽

RA Downie ◽

DP Thomson ◽

LA Clementson

Keyword(s):

Organic Matter ◽

Mytilus Edulis ◽

Particulate Organic Matter ◽

Coastal Waters ◽

Gill Tissue ◽

Suspension Feeder ◽

Food Sources ◽

Suspension Feeders ◽

Blue Mussels ◽

Suspended Particulate

Benthic suspension feeders, such as bivalves, potentially have several different food sources, including plankton and resuspended detritus of benthic origin. We hypothesised that suspension feeders are likely to feed on detritus if it is present. This inference would be further strengthened if there was a correlation between δ13C of suspension feeder tissue and δ13C of particulate organic matter (POM). Since detritus is characterised by high particulate organic matter (POC):chl a ratios, we would also predict a positive correlation between POM δ13C and POC:chl a. We hypothesised that increasing depth and greater distance from shore would produce a greater nutritional reliance by experimentally transplanted blue mussels Mytilus edulis on plankton rather than macrophyte-derived detritus. After deployments of 3 mo duration in 2 different years at depths from 3 to 40 m, M. edulis sizes were positively correlated with POM concentrations. POC:chl a ratios and δ13C of POM and M. edulis gill tissue decreased with increasing depth (and greater distance from shore). δ13C of POM was correlated with δ13C of M. edulis. Our results suggest that detritus comprised a large proportion of POM at shallow depths (<15 m), that M. edulis ingested and assimilated carbon in proportion to its availability in POM, and that growth of M. edulis was higher where detritus was present and POM concentrations were higher.

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On Candinia (Sacoglossa: Juliidae), a new fossil genus of bivalved gastropods

Journal of Paleontology ◽

10.1017/s0022336000023313 ◽

1996 ◽

Vol 70 (2) ◽

pp. 230-235 ◽

Cited By ~ 6

Author(s):

Jacques Le Renard ◽

Bruno Sabelli ◽

Marco Taviani

Keyword(s):

New Genus ◽

First Record ◽

Fossil Species ◽

Shallow Marine ◽

Marine Deposits ◽

The Family ◽

Life Habits ◽

The Mediterranean ◽

Fossil Genus ◽

The Mediterranean Basin

The record of the fossil representatives of the family Juliidae is updated. The new genus Candinia is proposed, in the subfamily Juliinae, for two fossil species somewhat intermediate between Julia and Berthelinia. The new species Candinia pliocaenica is recorded from the lower Pliocene shallow marine deposits near Siena (Tuscany, Italy). This is the first record of Sacoglossa in the Mediterranean Basin. Based on the very specialized life habits of the Juliidae, it is suggested that subtropical Caulerpa algal prairies inhabited the Mediterranean during the early Pliocene, likely becoming extinct in this basin because of the mid-Pliocene climatic deterioration.

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Trophic group and the end-Cretaceous extinction: did deposit feeders have it made in the shade?

Paleobiology ◽

10.1017/s0094837300016055 ◽

1996 ◽

Vol 22 (1) ◽

pp. 104-112 ◽

Cited By ~ 22

Author(s):

Jeffrey S. Levinton

Keyword(s):

Water Column ◽

Deep Sea ◽

Trophic Group ◽

Food Shortage ◽

Suspension Feeders ◽

Deposit Feeders ◽

Relative Ability ◽

Organic Particles ◽

Cretaceous Period ◽

Made In

It has been suggested that a sudden event at the end of the Cretaceous period caused a major extinction that was felt disproportionately by creatures in the water column. It also has been argued that benthic deposit feeders, being relatively independent of abundance of organic particles in the water column, should have survived the crisis more readily than suspension feeders, which depended more upon feeding upon phytoplankton. I argue that the hypothesis of relative immunity of deposit feeders is insufficient, because deposit feeders by and large depend upon a supply of organic matter from the water column and would have succumbed to food shortage nearly as rapidly as suspension feeders, possibly within a maximum of three to six months. This near simultaneity of extinction would have been especially true of continental shelf environments. Even in some parts of the deep sea, it is likely that a dependence upon the water column above might have caused deep-sea deposit feeders to succumb rapidly. Therefore, deposit feeders would not necessarily have outsurvived suspension feeders during a crisis of depleted water-column phytoplankton, increased shading by inert particles, or poisoning of the water column and killing of phytoplankton. The relatively lower rate of extinction of nuculoid bivalves may relate instead to their presence in deeper-water refuge habitats, their apparent relative ability to diversify in higher latitudes, or their resistance to factors other than food shortage.

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A review of Pachyvaranus crassispondylus Arambourg, 1952, a pachyostotic marine squamate from the latest Cretaceous phosphates of Morocco and Syria

Geological Magazine ◽

10.1017/s0016756810000580 ◽

2010 ◽

Vol 148 (2) ◽

pp. 237-249 ◽

Cited By ~ 14

Author(s):

ALEXANDRA HOUSSAYE ◽

NATHALIE BARDET ◽

JEAN-CLAUDE RAGE ◽

XABIER PEREDA SUBERBIOLA ◽

BAÂDI BOUYA ◽

...

Keyword(s):

Marine Environment ◽

Teleost Fish ◽

Shallow Marine ◽

Shallow Marine Environment ◽

Southern Margin ◽

Mode Of Life ◽

Aquatic Mode ◽

The Mediterranean ◽

Marine Reptile ◽

Detailed Diagnosis

AbstractThe discovery of new specimens of Pachyvaranus crassispondylus Arambourg, 1952 from the Maastrichtian phosphates of Morocco and Syria enables us to (1) redescribe in detail this poorly known varanoid lizard, (2) provide a more detailed diagnosis and (3) re-evaluate the systematic affinities of this taxon within squamates. The latter is placed in Pachyvaranidae nov., considered a new unranked clade of non-pythonomorph Varanoidea. The intense pachyosteosclerosis observed in the vertebrae and ribs suggests a primarily aquatic mode of life for Pachyvaranus. This is in accordance with the sedimentological context (shallow marine environment). As for its palaeobiogeographical distribution, Pachyvaranus is a component of the marine reptile assemblages from the southern margin of the Mediterranean Tethys, around palaeolatitudes 20° N. The osteoderms previously referred to this taxon by Arambourg are reanalysed and assigned to a teleost fish.

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A new molluscan assemblage from the pre-evaporitic Messinian of Crete (Greece)

10.5194/egusphere-egu2020-15647 ◽

2020 ◽

Author(s):

Efterpi Koskeridou ◽

Danae Thivaiou

Keyword(s):

Seagrass Beds ◽

Shallow Marine ◽

Environmental Consequences ◽

Environmental Perturbation ◽

New Material ◽

Molluscan Fauna ◽

First Time ◽

Molluscan Assemblage ◽

Hard Substrates ◽

Normal Salinity

The Messinian Salinity Crisis (MSC) was an environmental perturbation with dramatic environmental consequences that greatly affected marine organisms. Messinian deposits are found in several locations around the Mediterranean, but few offer marine faunas rich in molluscs. A section near Heraklion, central Crete, has provided new material that contains a well preserved and rich molluscan fauna that includes many micromorphic species. The section is of early Messinian age, belongs to Agios Miron Formation, and bears several layers of fossiliferous marly sands.Molluscs from a fossiliferous bed of the section are presented here for the first time. Gastropods and bivalves are most common, but scaphopods and chitons are not infrequent. The assemblage seems to be composed of transported elements from nearby environments and the most frequent species are present in comparable abundances for gastropods and bivalves. The gastropod fauna is represented by Bittium sp. and Gibbula sp., accompanied by Diodora cf. graeca, Turritella sp., Jujubinus sp., species of Pyramidellidae and rarer Homalopoma sp. and Haliotis sp. The presence of Bittium sp. together with Jujubinus sp. suggests vegetated environments. Bivalves are represented by species dwelling mostly in sandy environments such as Glycymeris cf. inflata (also occurring in larger specimens), Spisula sp., Timoclea sp. and various cardiids. Exceptionally well-preserved chitons indicate the presence of hard substrates such as rocks, pebbles or roots of seagrass beds. This is confirmed by the presence of the gastropods Diodora cf. graeca and Haliotis sp.The assemblage points towards normal salinity shallow marine conditions of sandy bottoms with patches of seagrass-type vegetation before the onset of the MSC.

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Was the Devonian placoderm Titanichthys a suspension feeder?

Royal Society Open Science ◽

10.1098/rsos.200272 ◽

2020 ◽

Vol 7 (5) ◽

pp. 200272 ◽

Cited By ~ 2

Author(s):

Samuel J. Coatham ◽

Jakob Vinther ◽

Emily J. Rayfield ◽

Christian Klug

Keyword(s):

Feeding Habits ◽

Temporal Distribution ◽

Suspension Feeder ◽

Von Mises Stress ◽

Cambrian Explosion ◽

Apex Predators ◽

Baleen Whales ◽

Suspension Feeders ◽

Whale Sharks ◽

Von Mises

Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an inherent relationship with ocean primary productivity and how past and future perturbations to these may impact on the different tiers of the food web. The evolution of large nektonic suspension feeders—‘gentle giants’—occurred four times among chondrichthyan fishes (e.g. whale sharks, basking sharks and manta rays), as well as in baleen whales (mysticetes), the Mesozoic pachycormid fishes and at least twice in radiodontan stem group arthropods (Anomalocaridids) during the Cambrian explosion. The Late Devonian placoderm Titanichthys has tentatively been considered to have been a megaplanktivore, primarily due to its gigantic size and narrow, edentulous jaws while no suspension-feeding apparatus have ever been reported. Here, the potential for microphagy and other feeding behaviours in Titanichthys is assessed via a comparative study of jaw mechanics in Titanichthys and other placoderms with presumably differing feeding habits (macrophagy and durophagy). Finite-element models of the lower jaws of Titanichthys termieri in comparison to Dunkleosteus terrelli and Tafilalichthys lavocati reveal considerably less resistance to von Mises stress in this taxon. Comparisons with a selection of large-bodied extant taxa of similar ecological diversity reveal similar disparities in jaw stress resistance. Our results, therefore, conform to the hypothesis that Titanichthys was a suspension feeder with jaws ill-suited for biting and crushing but well suited for gaping ram feeding.

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Ice algae resource utilization by benthic macro- and megafaunal communities on the Pacific Arctic shelf determined through lipid biomarker analysis

Marine Ecology Progress Series ◽

10.3354/meps13476 ◽

2020 ◽

Vol 651 ◽

pp. 23-43 ◽

Cited By ~ 1

Author(s):

CW Koch ◽

LW Cooper ◽

JM Grebmeier ◽

K Frey ◽

TA Brown

Keyword(s):

Organic Carbon ◽

Sea Ice ◽

Feeding Strategy ◽

Food Sources ◽

Ice Algae ◽

Surface Deposit ◽

Suspension Feeders ◽

Deposit Feeders ◽

Lipid Biomarker ◽

Biomarker Analysis

We studied ice algae utilization by benthic fauna from the northern Bering and Chukchi Seas using highly branched isoprenoid (HBI) biomarkers. We assessed whether various food acquisition strategies influence the observed HBI signatures. The proportion of phytoplankton to ice algae-sourced HBIs was determined through the H-Print approach that is presumed to reflect the percentage of sea ice organic carbon (iPOC) incorporated into tissues, relative to phytoplankton organic carbon. Cluster analysis separated 3 groups based on location and feeding strategy that were significantly influenced by annual sea ice persistence. Ice algae utilization was most significant in the northeast Chukchi Sea, where seasonal sea ice was present the longest. General feeding strategy was determined to be a significant factor in the degree of ice algae utilization. Predominant deposit feeders (both surface and subsurface) used more ice algae relative to suspension feeders. Organic carbon incorporated by predominant suspension feeders was primarily phytoplankton-based. The vast majority of all organisms sampled (~90%) incorporated a measurable quantity of iPOC. Sipunculids and brittle stars had the highest relative dependence on ice algae, while other taxa displayed plastic dietary responses, including the suspension/surface deposit feeder Macoma calcarea. This study indicates that ice algae are widely utilized in Pacific Arctic benthic food webs, but most benthic organisms displayed flexibility in consuming the available food sources. The elevated utilization of ice algae by deposit feeders may prove to be a disadvantage for these organisms if they cannot adapt to the ongoing decline of iPOC as seasonal sea ice declines.

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