Biogeographic and evolutionary patterns of continental margin benthic foraminifera

Paleobiology ◽  
1989 ◽  
Vol 15 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Martin A. Buzas ◽  
Stephen J. Culver
Keyword(s):  
North America ◽  
Continental Margin ◽  
Endemic Species ◽  
Benthic Foraminifera ◽  
Fossil Record ◽  
Data Sets ◽  
Evolutionary Patterns ◽  
Geographic Ranges ◽  
Centers Of Origin ◽  
Wide Geographic Distribution

Several very large, taxonomically standardized data sets have been compiled and utilized to investigate biogeographic and evolutionary patterns of continental margin benthic foraminifera. Mean partial species durations for 87 frequently occurring and 180 rarely occurring species on the Atlantic continental margin of North America are the same, namely 21 m.y. The global fossil record of these species indicates no center or centers of origin and indicates very rapid dispersal. The Miocene had the greatest number of first occurrences with 46%, followed by the Pleistocene, Pliocene and Oligocene with approximately 13% each. The remaining 14% first occur in the Eocene, Paleocene, and Cretaceous. Species with a wide geographic distribution often exhibit longer species durations than those with narrow geographic ranges. The vast majority of endemic species (150 of 175) occur rarely and have no fossil record.

scholarly journals Biogeographic and evolutionary patterns of change in the terrestrial biota across the Cretaceous\Tertiary boundary

1992 ◽  
Vol 6 ◽  
pp. 60-60
Author(s):  
William A. Clemens
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
Taxonomic Diversity ◽  
High Latitudes ◽  
Apparent Paradox ◽  
Evolutionary Patterns ◽  
Geographic Ranges ◽  
Terrestrial Vertebrates ◽  
Terrestrial Biota ◽  
Fossil Records

The currently available fossil record suggests, 1) biogeographic differentiation of the Late Cretaceous terrestrial biota and, 2) distinctly different patterns of evolution of terrestrial faunas and floras across the Cretaceous\Tertiary boundary.Discovery in Alaska of dinosaurs and mammals that lived at Late Cretaceous northern high latitudes provides evidence that many groups of terrestrial vertebrates had extensive geographic ranges and faunas were biogeographically differentiated. The Alaskan dinosaurs, represented by individuals that range in size from hatchlings to adults, might have been migratory forms living at high latitudes only during the summer months. In contrast, the small mammals probably were not migratory.Although recent discoveries are expanding our knowledge of the evolution of the terrestrial biota, the fossil record of terrestrial vertebrates during the Cretaceous\Tertiary transition is still heavily biased in favor of the northern Western Interior of North America. Here evolutionary change of the terrestrial fauna did not just involve extinction of lineages, some already decreasing in taxonomic diversity, and survival of many others. Shifts in biogeographic range and immigration of new groups played a significant role in remodeling the terrestrial fauna. The paleobotanical record is more extensive but also is biased with the most detailed record coming from the Western Interior where floral change is characterized as “massive” or “catastrophic” in scope.These conflicting evolutionary patterns are well founded being based on analysis of substantial fossil records. A new program of research directed toward resolution of the apparent paradox tests the hypothesis that at the end of the Cretaceous the terrestrial biota was biogeographically heterogeneous and evolutionary patterns of faunal and floral change in the Western Interior cannot be taken as globally representative.

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

scholarly journals Oceanographic parameters in continental margin of the State of Ceará (northeastern Brazil) deduced from C and O isotopes in foraminifers

2007 ◽  
Vol 79 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Wanessa S. Marques ◽  
Eldemar de A. Menor ◽  
Alcides N. Sial ◽  
Valdir A.V. Manso ◽  
Satander S. Freire
Keyword(s):  
Continental Margin ◽  
Benthic Foraminifera ◽  
Linear Equations ◽  
The State ◽  
Northeastern Brazil ◽  
Oceanic Water ◽  
Ocean Water ◽  
Oxygen Utilization ◽  
Carbon And Oxygen Isotopes ◽  
Planktic Foraminifera

Specimens of Recent foraminifera of Amphistegina radiata, Peneroplis planatus and Globigerinoides ruber, from fifty samples of surface sediments of the continental margin of the State of Ceará, Brazil, have been analyzed for carbon and oxygen isotopes to investigate oceanographic parameters and determine the values of delta18O of the oceanic water. From a comparison between values of delta18O obtained for ocean water using the linear equations by (Craig and Gordon 1965) and the one by Wolff et al. (1998), it became evident that the former yielded a more reliable value (0.2‰ SMOW) than the latter. Lower values of delta18O for the ocean water in this continental margin resulted from continental water influence. Values of 18O (-0.3‰ to -1.5‰ PDB for benthic foraminifera and -0.6‰ to -2.4‰ PDB for planktic foraminifera), attest to a variation of temperatures of oceanic water masses, in average, between 20 to 22ºC in deep water and 24 to 27ºC, in surface water. Values of delta13C from +3.2‰ to -0.2‰ PDB (benthic foraminifera) reflect a variation in the apparent oxygen utilization (AOU) in the continental margin and indicate that the environments of bacteriological decomposition of organic matter are not continuous along the investigated area.

Do centers of origin have a center?

Paleobiology ◽  
1981 ◽  
Vol 7 (3) ◽  
pp. 305-307 ◽  
Author(s):  
John C. Briggs
Keyword(s):  
United States ◽  
North America ◽  
Southeastern United States ◽  
Important Criterion ◽  
Centers Of Origin ◽  
Single Region ◽  
Evolutionary Radiation ◽  
A Current ◽  
Considerable Intensity

A current question being debated with considerable intensity is whether or not certain geographic areas act as centers of evolutionary radiation and supply species to other areas that are less active or less effective in an evolutionary sense. Darwin (1859) was the first to write about centers of origin which he called “single centers of creation.” He argued that each species was first produced within a single region and that it subsequently migrated from that area as far as its powers of migration and subsistence under past and present conditions permitted. Adams (1902), in discussing the influence of the southeastern United States as a center of distribution for the flora and fauna of North America, provided a series of criteria for the determination of “centers of dispersal.” His first, and evidently most important criterion was the location of “the greatest differentiation of a type.”

Early Silurian Benthic Foraminifera from Saudi Arabia - including the oldest known multichambered lituolids

Stratigraphy ◽  
2020 ◽  
pp. 141-185
Author(s):  
Michael A. Kaminski ◽  
Pramudya R. D. Perdana
Keyword(s):  
Saudi Arabia ◽  
New Species ◽  
North America ◽  
Benthic Foraminifera ◽  
Early Evolution ◽  
Foraminiferal Assemblage ◽  
New Findings ◽  
New Finding ◽  
Agglutinated Foraminifera

ABSTRACT: A diverse assemblage of early Silurian agglutinated foraminifera is described from the transitional facies between the Qusaiba and Sharawra Formations of theQalibah Group of Saudi Arabia. The agglutinated foraminiferal assemblage consists of 73 species belonging to 24 genera, and is found in in dark graptolite-bearing claystone of Aeronian age. The assemblage is highly diverse compared with coeval early Silurian assemblages reported from Europe and North America. The assemblage is comprised mainly of species belonging to the monothalamid genera Saccammina, Psammosphaera, Lagenammina, Thurammina, Thuramminoides, Amphitremoida, Bathysiphon, Rhabdammina, and the tubothalamid genera Hyperammina, Tolypammina and Turritellella. The new species Thuramminoides ellipsoidalis n. sp. is described herein, but many of the species left in open nomenclature are also likely to be new. The assemblage also includes rare specimens belonging to the globothalamid (lituolid) genera Ammobaculites and Simobaculites. This new finding revises our understanding of the early evolution of the multichambered globothalamid foraminifera. Although the simple multichambered with rectilinear chamber arrangement are known from the Ordovician, our new findings show that the coiled globothalamids belonging to the order Lituolida are older than previously thought, and were already present in Gondwana by about 440 Ma.

Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation

2021 ◽  
pp. 1-15
Author(s):  
Thomas M. Cullen ◽  
Lindsay Zanno ◽  
Derek W. Larson ◽  
Erinn Todd ◽  
Philip J. Currie ◽  
...  
Keyword(s):  
High Resolution ◽  
North America ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
Environmental Changes ◽  
Morphometric Analyses ◽  
Variable Distribution ◽  
Taxic Diversity ◽  
Dinosaur Park Formation ◽  
Broad Scale

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one of the most diverse dinosaur faunas, with the record favouring large-bodied taxa, in terms of number and completeness of skeletons. Although small theropods are well documented in the assemblage, taxonomic assessments are frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, and morphometric analyses, with a focus on specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, we test whether DPF theropods preserve faunal zonation/turnover patterns similar to those previously documented for megaherbivores. Frontal bones referred to a therizinosaur (cf. Erlikosaurus), representing among the only skeletal record of the group from the Campanian–Maastrichtian (83–66 Ma) fossil record of North America, plot most closely to troodontids in morphospace, distinct from non-DPF therizinosaurs, a placement supported by a suite of troodontid anatomical frontal characters. Postcranial material referred to cf. Erlikosaurus in North America is also reviewed and found most similar in morphology to caenagnathids, rather than therizinosaurs. Among troodontids, we document considerable morphospace and biostratigraphic overlap between Stenonychosaurus and the recently described Latenivenatrix, as well as a variable distribution of putatively autapomorphic characters, calling the validity of the latter taxon into question. Biostratigraphically, there are no broad-scale patterns of faunal zonation similar to those previously documented in ornithischians from the DPF, with many theropods ranging throughout much of the formation and overlapping extensively, possibly reflecting a lack of sensitivity to environmental changes, or other cryptic ecological or evolutionary factors.

A review of gall midges (Diptera: Cecidomyiidae) described from Mesozoic deposits

2021 ◽  
Vol 4 (1) ◽  
pp. 001-014
Author(s):  
MATHIAS JASCHHOF
Keyword(s):  
New Zealand ◽  
North America ◽  
Fossil Record ◽  
Morphological Diversity ◽  
Sensu Stricto ◽  
Junior Synonym ◽  
Gall Midges ◽  
Incertae Sedis ◽  
New Tribe

Twenty-four fossil gall midges (Cecidomyiidae) described from 1917–2020 from Mesozoic deposits, mostly ambers, are reviewed. Information from the original publications is used as the basis for reinterpretation, when such is regarded as appropriate here. As a result, the fossil record of cecidomyiids from the Mesozoic comprises representatives of the following subfamilies and tribes, all mycophagous (numbers in parentheses refer to species described): Catotrichinae (1); Micromyinae: Catochini (2), Amediini (1), Campylomyzini (1), Micromyini (2) and Aprionini (1); Winnertziinae: Heteropezini (2), Diallactiini (4) and Winnertziini (1); Porricondylinae: Dicerurini (1). Other Winnertziinae (3) and Micromyinae (5) cannot be classified to tribe because information on critical morphological structures is unavailable; they are thus considered incertae sedis. Members of the Lestremiinae sensu stricto are unrecorded from the Mesozoic, as are any Cecidomyiinae (the only subfamily containing phytophages and predators). Commonly occurring reasons for misinterpretation of amber fossils are the non-recognition of artefacts and the unfamiliarity with group-specific literature regarding prevailing taxonomic concepts and the morphological diversity found in Cecidomyiidae. These causes as well as obvious differences between neontological and paleontological taxonomic practices are discussed. Amediini trib. nov. Jaschhof, 2021 is introduced as a new tribe of the Micromyinae, to absorb the genera Amedia Jaschhof, 1997 (extant, North America, type genus), Amediella Jaschhof, 2003 (extant, New Zealand) and Eltxo Arillo & Nel, 2000 (extinct, Alava amber). A diagnosis of the new tribe is given. Krassiloviolini Fedotova & Perkovsky, 2017 is a new junior synonym of Heteropezini Schiner, 1868. Amediini Plakidas, 2017 and Zarqacecidomyius singularis Kaddumi, 2007 are nomina nuda.

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