scholarly journals Palaeoecology of tropical marine invertebrate assemblages from Misurina (Late Triassic; Dolomites, Italy)

2021 ◽  
Vol 66 ◽  
Author(s):  
Imelda Hausmann ◽  
Alexander Nützel ◽  
Vanessa Roden ◽  
Mike Reich
Keyword(s):  
Marine Invertebrate ◽  
Late Triassic ◽  
Invertebrate Assemblages

Mass extinction patterns of marine invertebrate groups and some implications for a causal phenomenon

Paleobiology ◽  
1985 ◽  
Vol 11 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Michael L. McKinney
Keyword(s):  
Late Cretaceous ◽  
Mass Extinction ◽  
Marine Invertebrate ◽  
Relative Increase ◽  
Late Triassic ◽  
Extinction Rate ◽  
Marine Fauna ◽  
Taxonomic Groups ◽  
Extinction Events ◽  
Mass Extinction Events

A nonparametric analysis of the extinction patterns of 10 major marine invertebrate groups at the five most profound mass extinction events leads to five observations: (1) At each event some taxonomic groups were affected much more than others. (2) There is little consistency among events in terms of which taxonomic groups were most or least affected; however, adaptive groupings do exhibit consistency: benthic, mobile organisms suffered significantly fewer extinctions than sessile suspension feeders, while the pelagic organisms apparently suffered the most. (3) There are no convincing patterns of interrelated extinctions among taxonomic groups. (4) No group exhibits a persistent tendency through time for a relative increase or decrease in their extinction rate at the events. (5) Some relationships are seen between the extinction patterns of three pairs of events; the Late Ordovician and Late Devonian events exhibit a significantly similar pattern (the same taxonomic groups suffered the most extinction in both cases) as do the Late Triassic and Late Cretaceous events. The Late Permian and Late Cretaceous events show a significantly inverse pattern (the most affected groups in the former were among the least affected in the latter). Upon examination, these observations, notably 1, 2, and 5, are consonant with current scenarios of the effects of catastrophic bolide impacts on marine fauna.

scholarly journals Diversity patterns of Middle Permian gastropod assemblages from the Tak Fa Formation, Central Thailand

2021 ◽  
Author(s):  
Chatchalerm Ketwetsuriya ◽  
Imelda M. Hausmann ◽  
Alexander Nützel
Keyword(s):  
Marine Invertebrate ◽  
Diversity Indices ◽  
Taxonomic Composition ◽  
Depositional Environments ◽  
Middle Permian ◽  
Late Triassic ◽  
Diversity Gradient ◽  
Cassian Formation ◽  
Central Thailand ◽  
Rank Abundance

AbstractMiddle Permian marine invertebrate assemblages from Central Thailand are strongly dominated by gastropods. Two gastropod assemblages from the Tak Fa Limestone at Khao Noi and Khao Chao Thong of the Nakhon Sawan area are the first Permian ones from Thailand that are analysed regarding diversity and composition based on quantitative data. Both gastropod assemblages, comprising 40 species in total, are dominated by the gastropods Anomphalus sp., Warthia cf. brevisinuata and Glabrocingulum magnum; the genus Anomphalus is especially abundant which is unusual for Permian assemblages. Both studied gastropod assemblages have a similar taxonomic composition and diversity including the same values of diversity indices that indicate a moderate diversity. In addition, rarefaction analyses and rank-abundance distributions also suggest that diversity and structure of both assemblages are the same. The studied assemblage is compared with other Permian gastropod assemblages from Asia (Malaysia, East Timor and Japan). Rarefaction, diversity indices and rank-abundance distributions suggest that the diversity of the studied fauna is distinctly lower than that of the others despite coming from similar depositional environments. This is surprising because the Tak Fa gastropods lived at lower latitudes than the others. This could suggest an inverse diversity gradient in the Palaeo-Tethys, but more evidence is needed to substantiate this assumption. Several Late Palaeozoic and Early Mesozoic fossil assemblages are dominated by gastropods, e.g. those from the Pennsylvanian Buckhorn Asphalt deposit, the Permian from Japan and Malaysia, as well as the Late Triassic Cassian Formation. This shows that at least locally, gastropod dominance is not restricted to modern faunas.

scholarly journals Sampling-standardized expansion and collapse of reef building in the Phanerozoic

Fossil Record ◽  
2008 ◽  
Vol 11 (1) ◽  
pp. 7-18 ◽  
Author(s):  
W. Kiessling
Keyword(s):  
Fossil Record ◽  
Late Jurassic ◽  
Marine Invertebrate ◽  
Late Triassic ◽  
Late Devonian ◽  
Reef Growth ◽  
Temporal Scales ◽  
Natural Processes ◽  
Invertebrate Fossils

Tracing the variability of reef production over long temporal scales is important to approach natural processes favoring or suppressing reef growth. Raw compilations of reef abundance per unit of time do not necessarily depict biologically meaningful patterns, because the waxing and waning of reefs might just follow the quality of the fossil record, that is, the amount of paleontological information that is available in general. Here I standardize the published record of Phanerozoic reefs, as stored in the PaleoReefs database, to the published record of marine invertebrate fossils as stored in the Paleobiology Database. The sampling-standardized peaks in reef growth are essentially identical to those of previous studies, but significant peaks are rare. Times when unusual changes in ecological conditions are likely to control changes in metazoan reef proliferation were identified in the Late Devonian, Late Triassic, Late Jurassic and Neogene. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.200700008" target="_blank">10.1002/mmng.200700008</a>

scholarly journals Paleobiogeography of Mesozoic articulate brachiopods from the Western Cordillera of North America and their potential for paleogeographic studies

1992 ◽  
Vol 6 ◽  
pp. 259-259
Author(s):  
Michael R. Sandy
Keyword(s):  
North America ◽  
Marine Invertebrate ◽  
Common Species ◽  
Upper Triassic ◽  
Late Triassic ◽  
Additional Time ◽  
Larval Stages ◽  
Western Cordillera ◽  
North American Craton ◽  
Brachiopod Fauna

Mesozoic brachiopods were, at times, significant elements of marine invertebrate faunas. Current investigations suggest that Mesozoic brachiopods are more common in Mesozoic marine sequences from North America than has generally been assumed. Their neglect is no doubt in part due to the greater utility of other invertebrate and microfossil groups for biostratigraphy. Brachiopods may be preserved in original shell material or silicified. It is therefore necessary to consider which is the most appropriate method of extraction, depending on type of preservation.Lacking planktotrophic larval stages, living articulate brachiopods are limited in their dispersal potential by virtue of their sessile, benthic mode of life. If, in addition, all post-Paleozoic articulate brachiopods possessed a non-planktotrophic larval stage endemism would be likely to develop if gene-flow became severed. This would mean that taxonomic investigation of articulate brachiopods has the potential to provide useful paleobiogeographic and paleogeographic information. Recent investigations have concentrated on making a preliminary survey of some brachiopod occurrences in the Western Cordillera of North America with these goals in mind.The Upper Triassic brachiopod fauna from the Luning Formation of the Pilot and Shoshone Mountains, Nevada, is the most diverse known for the Mesozoic of North America in terms of number of brachiopod species (manuscript submitted with George D. Stanley). This is probably a reflection of how little detailed collecting and systematic study Mesozoic representatives of the phylum have received in North America. The fauna comprises both Tethyan and endemic species. The brachiopods are from the Paradise terrane, probably close to the North American craton in the Late Triassic. One Upper Triassic brachiopod fauna from the Antimonio Formation, Sonora, is by comparison with the Nevada faunas, depauperate, but they do share one common species. Additional time-equivalent brachiopod faunas from outboard terranes of North America and the “classic” European faunas monographed in the nineteenth and early twentieth centuries require investigation to determine their paleobiogeography and their contribution to paleogeography.Jurassic brachiopods from North America have not been subjected to any major revision but they are present at certain horizons. Cretaceous faunas from the southern United States and Mexico contain genera known from Tethys in Europe. Mid-Cretaceous faunas from the Queen Charlotte Islands (Wrangellia terrane) and the Canadian Arctic Islands contain forms that are more typical of mid-latitude to Boreal regions, repectively, of Europe. This suggests a broad correspondence between brachiopod distributions and paleolatitude across considerable paleolongitudinal distances, an observation of relevance to interpreting Early Mesozoic paleobiogeographic distributions.The current work is only scratching the surface of the Phylum's distribution in the Western Cordillera of North America. The aim is to provide a better understanding of brachiopod paleobiogeography, paleogeography, and the evolutionary history of the Brachiopoda during the post-Paleozoic, which does not appear to be their swansong.

Carcasses on the coastline: measuring the ecological fidelity of the cetacean stranding record in the eastern North Pacific Ocean

Paleobiology ◽  
2010 ◽  
Vol 36 (3) ◽  
pp. 453-480 ◽  
Author(s):  
Nicholas D. Pyenson
Keyword(s):  
Community Structure ◽  
Pacific Ocean ◽  
North Pacific ◽  
Marine Invertebrate ◽  
Spatial Scales ◽  
North Pacific Ocean ◽  
Line Transect ◽  
High Fidelity ◽  
Invertebrate Assemblages ◽  
The U.S

To understand how well fossil assemblages represent original communities, paleoecologists seek comparisons between death assemblages and their source communities. These comparisons have traditionally used nearshore, marine invertebrate assemblages for their logistical ease, high abundance, and comparable census data from living communities. For large marine vertebrates, like cetaceans, measuring their diversity in ocean ecosystems is difficult and expensive. Cetaceans, however, often beach or strand themselves along the coast, and archived data on stranded cetaceans have been recorded, in some areas, over several decades. If the stranding record is interpreted as a death assemblage, then the stranding record may represent a viable alternative for measuring diversity in living communities on directly adjacent coastlines. This study assessed the fidelity of the cetacean stranding record in the eastern North Pacific Ocean. The living community in this region has been studied for over 100 years and, recently, extensive and systematic live transect surveys using ship-based observing platforms have produced a valuable source of live diversity data. Over this same period, the U.S. Marine Mammal Stranding Program has collected and archived a record of cetacean strandings along the U.S. Pacific coastline, providing an ideal death assemblage for comparison. Using fidelity metrics commonly used in marine invertebrate taphonomy, I determined that the stranding record samples the living cetacean community with high fidelity, across fine and coarse taxonomic ranks, and at large geographic scales (>1000 km of coastline). The stranding record is also richer than the live surveys, with live-dead ratios between 1.1 and 1.3. The stranding record recovers similar rank-order relative abundances as live surveys, with statistical significance. Also, I applied sample-based rarefaction methods to generate collector's curves for strandings along the U.S. Pacific Coast to better evaluate the spatiotemporal characteristics of the stranding record. Results indicate that saturation (i.e., sampling >95% assemblage) at species, genus, and family levels occurs in less than five years of sampling, with families accumulating faster than species, and larger geographic regions (i.e., longer coastlines) accumulating taxa the most rapidly. The high fidelity of the stranding record, measured both in richness and by ranked relative abundance, implies that ecological structure from living cetacean communities is recorded in the death assemblage, a finding that parallels marine invertebrate assemblages, though at far larger spatial scales. These results have implications for studying cetacean ecology in both modern and ancient environments: first, these results imply that the stranding record, over sufficiently long time intervals, yields a richer assemblage than using line-transect methods, and faithfully records aspects of community structure; and second, these results imply that geochronologically well-constrained fossil cetacean assemblages might preserve ecologically relevant features of community structure, depending on depositional and taphonomic conditions.

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