Late Cretaceous palaeoenvironments and biotas: an Antarctic perspective

The Cretaceous period is often regarded as one of "greenhouse" warmth, with perhaps its acme occurring in the late Albian stage (100 Ma ago). However, it is now apparent that, even at this time, there were significant meridional temperature gradients and distinct temperate biotas in the highest latitude regions. This is particularly so in the Southern Hemisphere, where an extensive Albian fossil record from Antarctica, Australia and New Zealand has revealed the presence of austral floras and faunas. With the recent improvements in stratigraphical correlations, it has become possible to trace the later Cretaceous palaeoenvironmental record in the Antarctic Peninsula region. Unfortunately, resolution of the early Late Cretaceous (Cenomanian–Coniacian stages) is still imprecise; there are some indications of strongly differentiated palynological assemblages, but studies of both macrofaunas and palaeotemperature estimates are incomplete. By the Santonian–Campanian, high-latitude biotas are well developed in the James Ross Island region and their enhancement through the final stages of the Cretaceous can be linked to a phase of global cooling. The persistence of low diversity temperate communities in high latitude regions may be of considerable ecological and evolutionary significance. For example, there is evidence to suggest that these communities may have been more resistant to mass extinction events; they may also have been important source regions for replacement taxa that arose after such events.

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Nannofossils, foraminifera and microforaminiferal linings in the Cenozoic diamictites of Cape Lamb, Vega Island, Antarctica

Polish Polar Research ◽

10.2478/popore-2014-0003 ◽

2014 ◽

Vol 35 (1) ◽

pp. 1-26 ◽

Cited By ~ 6

Author(s):

Andrea Concheyro ◽

Andrea Caramés ◽

Cecilia R. Amenábar ◽

Marina Lescano

Keyword(s):

Early Cretaceous ◽

Late Cretaceous ◽

First Record ◽

Organic Layer ◽

Sediment Sources ◽

Lower Maastrichtian ◽

James Ross Island ◽

The Antarctic ◽

Upper Maastrichtian ◽

Upper Campanian

AbstractMicropaleontological and palynological samples from three Cenozoic diamictites at Cape Lamb, Vega Island, James Ross Basin were analysed. Fossiliferous samples yielded reworked and autochthonous assemblages of Mesozoic calcareous nanno− fossils, impoverished Cretaceous foraminifera together with Neogene species, as well as Late Cretaceous dinoflagellate cysts, pollen, spores and abundant Cenozoic micro− foraminiferal linings. The recovered nannoflora indicates Early Cretaceous (Hauteri− vian-Albian) and Late Cretaceous (Santonian-Early Campanian) ages, suggesting an in− tensive reworking of marine sediments. The presence of the Early Cretaceous species Nannoconus circularis Deres et Acheriteguy in the diamictite represents its first record for the James Ross Basin. The scarce foraminiferal fauna includes Pullenia jarvisi Cushman, which indicates reworking from lower Maastrichtian-lower Paleocene sediments, and also the Neogene autochthonous Trochammina sp. aff. T. intermedia. The in− ner−organic layer observed inside this specimen appears to be identical to microfora− miniferal linings recovered from the same sample. Palynomorphs found in the studied samples suggest erosion from the underlying Snow Hill Island and the Lopez de Bertodano Formation beds (upper Campanian-upper Maastrichtian). These recovered assemblages indicate either different periods of deposition or reworking from diverse sources during Cenozoic glaciation, originating in James Ross Island and the Antarctic Peninsula with the influence of local sediment sources.

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

Paleobiology ◽

10.1017/s0094837300011532 ◽

1985 ◽

Vol 11 (2) ◽

pp. 227-233 ◽

Cited By ~ 19

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.

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Mass Extinctions as Statistical Phenomena: An Examination of the Evidence Using χ2 Tests and Bootstrapping

Paleobiology ◽

10.1017/s0094837300013944 ◽

1992 ◽

Vol 18 (2) ◽

pp. 148-160 ◽

Cited By ~ 16

Author(s):

Alan E. Hubbard ◽

Norman L. Gilinsky

Keyword(s):

Late Cretaceous ◽

Mass Extinction ◽

Late Ordovician ◽

Statistical Evidence ◽

Mass Extinctions ◽

Late Permian ◽

Turnover Rates ◽

Historical Evidence ◽

Extinction Events ◽

Mass Extinction Events

Although much natural historical evidence has been adduced in support of the occurrence of several mass extinctions during the Phanerozoic, unambiguous statistical confirmation of the mass extinction phenomenon has remained elusive. Using bootstrapping techniques that have not previously been applied to the study of mass extinction, we have amassed strong or very strong statistical evidence for mass extinctions (see text for definitions) during the Late Ordovician, Late Permian, and Late Cretaceous. Bootstrapping therefore verifies three of the mass extinction events that were proposed by Raup and Sepkoski (1982). A small amount of bootstrapping evidence is also presented for mass extinctions in the Induan (Triassic) and Coniacean (Cretaceous) Stages, but high overall turnover rates (including high origination) in the Induan and uncertain estimates of the temporal duration of the Coniacean force us to conclude that the evidence is not compelling.We also present the results of more liberal X2 tests of the differences between expected and observed numbers of familial extinctions for stratigraphic stages. In addition to verifying the mass extinctions identified using bootstrapping, these analyses suggest that several stages that could not be verified as mass extinction stages using bootstrapping (including the last three in the Devonian, and the Norian Stage of the Triassic) should still be regarded as candidates for mass extinction. Further analysis will be required to test these stages in more detail.

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An ornithopod dinosaur from the Late Cretaceous of West Antarctica

Antarctic Science ◽

10.1017/s0954102091000391 ◽

1991 ◽

Vol 3 (3) ◽

pp. 331-332 ◽

Cited By ~ 31

Author(s):

J.J. Hooker ◽

A.C. Milner ◽

S.E.K. Sequeira

Keyword(s):

Antarctic Peninsula ◽

Late Cretaceous ◽

West Antarctica ◽

Island Area ◽

British Antarctic Survey ◽

James Ross Island ◽

The Antarctic ◽

Partial Skeleton

In February 1989, the partial skeleton of an ornithopod dinosaur was discovered during a British Antarctic Survey (BAS) expedition, supported by RRS John Biscoe, to the James Ross Island area, east of the Antarctic Peninsula. This was only the second dinosaur to be found in the continent of Antarctica, the first being an ankylosaur collected three years earlier (Olivero et al. 1986, Gasparini et al. 1987, Gasparini 1988, Gasparini & Olivero 1989, Olivero et al. 1991).

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Vegetation-induced warming of high-latitude regions during the Late Cretaceous period

Nature ◽

10.1038/385804a0 ◽

1997 ◽

Vol 385 (6619) ◽

pp. 804-807 ◽

Cited By ~ 125

Author(s):

Bette L. Otto-Bliesner ◽

Garland R. Upchurch

Keyword(s):

Late Cretaceous ◽

High Latitude ◽

Late Cretaceous Period ◽

Cretaceous Period

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CHARACTERIZATION OF SEDIMENTS DEPOSITED ON THE SIOUX RIDGE OF SOUTHEASTERN SOUTH DAKOTA DURING THE LATE CRETACEOUS PERIOD

10.1130/abs/2019sc-327077 ◽

2019 ◽

Author(s):

Stevie L. Holmes ◽

Keyword(s):

South Dakota ◽

Late Cretaceous ◽

Late Cretaceous Period ◽

Cretaceous Period

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Modeling Extinction

10.1093/oso/9780195159455.001.0001 ◽

2003 ◽

Author(s):

M. E. J. Newman ◽

R. G. Palmer

Keyword(s):

Evolutionary Biology ◽

Large Scale ◽

Competitive Exclusion ◽

Applied Mathematics ◽

Santa Fe ◽

New Approach ◽

Self Organized ◽

Self Organized Criticality ◽

Extinction Events ◽

Mass Extinction Events

Developed after a meeting at the Santa Fe Institute on extinction modeling, this book comments critically on the various modeling approaches. In the last decade or so, scientists have started to examine a new approach to the patterns of evolution and extinction in the fossil record. This approach may be called "statistical paleontology," since it looks at large-scale patterns in the record and attempts to understand and model their average statistical features, rather than their detailed structure. Examples of the patterns these studies examine are the distribution of the sizes of mass extinction events over time, the distribution of species lifetimes, or the apparent increase in the number of species alive over the last half a billion years. In attempting to model these patterns, researchers have drawn on ideas not only from paleontology, but from evolutionary biology, ecology, physics, and applied mathematics, including fitness landscapes, competitive exclusion, interaction matrices, and self-organized criticality. A self-contained review of work in this field.

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Out of the Neotropics: Late Cretaceous colonization of Australasia by American arthropods

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.0675 ◽

2012 ◽

Vol 279 (1742) ◽

pp. 3501-3509 ◽

Cited By ~ 41

Author(s):

Prashant P. Sharma ◽

Gonzalo Giribet

Keyword(s):

Late Cretaceous ◽

Divergence Time ◽

Disjunct Distribution ◽

Continental Margins ◽

Divergence Time Estimates ◽

Evolutionary Origins ◽

Source Regions ◽

Time Estimates ◽

Fiji Islands ◽

The Pacific

The origins of tropical southwest Pacific diversity are traditionally attributed to southeast Asia or Australia. Oceanic and fragment islands are typically colonized by lineages from adjacent continental margins, resulting in attrition of diversity with distance from the mainland. Here, we show that an exceptional tropical family of harvestmen with a trans-Pacific disjunct distribution has its origin in the Neotropics. We found in a multi-locus phylogenetic analysis that the opilionid family Zalmoxidae, which is distributed in tropical forests on both sides of the Pacific, is a monophyletic entity with basal lineages endemic to Amazonia and Mesoamerica. Indo-Pacific Zalmoxidae constitute a nested clade, indicating a single colonization event. Lineages endemic to putative source regions, including Australia and New Guinea, constitute derived groups. Divergence time estimates and probabilistic ancestral area reconstructions support a Neotropical origin of the group, and a Late Cretaceous ( ca 82 Ma) colonization of Australasia out of the Fiji Islands and/or Borneo, which are consistent with a transoceanic dispersal event. Our results suggest that the endemic diversity within traditionally defined zoogeographic boundaries might have more complex evolutionary origins than previously envisioned.

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Mass extinctions alter extinction and origination dynamics with respect to body size

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.1681 ◽

2021 ◽

Vol 288 (1960) ◽

Author(s):

Pedro M. Monarrez ◽

Noel A. Heim ◽

Jonathan L. Payne

Keyword(s):

Body Size ◽

Mass Extinction ◽

Evolutionary Biology ◽

Marine Animal ◽

Mass Extinctions ◽

Extinction Selectivity ◽

Extinction Events ◽

Mass Extinction Events ◽

Marine Biosphere

Whether mass extinctions and their associated recoveries represent an intensification of background extinction and origination dynamics versus a separate macroevolutionary regime remains a central debate in evolutionary biology. The previous focus has been on extinction, but origination dynamics may be equally or more important for long-term evolutionary outcomes. The evolution of animal body size is an ideal process to test for differences in macroevolutionary regimes, as body size is easily determined, comparable across distantly related taxa and scales with organismal traits. Here, we test for shifts in selectivity between background intervals and the ‘Big Five’ mass extinction events using capture–mark–recapture models. Our body-size data cover 10 203 fossil marine animal genera spanning 10 Linnaean classes with occurrences ranging from Early Ordovician to Late Pleistocene (485–1 Ma). Most classes exhibit differences in both origination and extinction selectivity between background intervals and mass extinctions, with the direction of selectivity varying among classes and overall exhibiting stronger selectivity during origination after mass extinction than extinction during the mass extinction. Thus, not only do mass extinction events shift the marine biosphere into a new macroevolutionary regime, the dynamics of recovery from mass extinction also appear to play an underappreciated role in shaping the biosphere in their aftermath.

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Pathways and timescales of connectivity around the Antarctic continental shelf

10.5194/egusphere-egu21-14011 ◽

2021 ◽

Author(s):

Hannah Dawson ◽

Adele Morrison ◽

Veronica Tamsitt ◽

Matthew England

Keyword(s):

Continental Shelf ◽

Ross Sea ◽

Coastal Current ◽

West Antarctica ◽

Source Regions ◽

Freshwater Forcing ◽

Antarctic Continental Shelf ◽

Antarctic Continent ◽

Antarctic Slope Current ◽

The Antarctic

The Antarctic margin is surrounded by two westward flowing currents: the Antarctic Slope Current and the Antarctic Coastal Current. The former influences key processes near the Antarctic margin by regulating the flow of heat and nutrients onto and off the continental shelf, while together they advect nutrients, biological organisms, and temperature and salinity anomalies around the coastline, providing a connective link between different shelf regions. However, the extent to which these currents transport water from one sector of the continental shelf to another, and the timescales over which this occurs, remain poorly understood. Concern that crucial water formation sites around the Antarctic coastline could respond to non-local freshwater forcing from ice shelf meltwater motivates a more thorough understanding of zonal connectivity around Antarctica. In this study, we use daily velocity fields from a global high-resolution ocean-sea ice model, combined with the Lagrangian tracking software Parcels, to investigate the pathways and timescales connecting different regions of the Antarctic continental shelf with a view to understanding the timescales of meltwater transport around the continent. Virtual particles are released over the continental shelf, poleward of the 1000 metre isobath, and are tracked for 20 years. Our results show a strong seasonal cycle connecting different sectors of the Antarctic continent, with more particles arriving further downstream during winter than during summer months. Strong advective links exist between West Antarctica and the Ross Sea while shelf geometry in some other regions acts as barriers to transport. We also highlight the varying importance of the Antarctic Slope Current and Antarctic Coastal Current in connecting different sectors of the coastline. Our results help to improve our understanding of circum-Antarctic connectivity and the timescales of meltwater transport from source regions to downstream shelf locations. Furthermore, the timescales and pathways we present provide a baseline from which to assess long-term changes in Antarctic coastal circulation due to local and remote forcing.

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