Evolution of Menispermaceae

1986 ◽  
Vol 64 (12) ◽  
pp. 3130-3133 ◽  
Author(s):  
G. Thanikaimoni
Keyword(s):  
North America ◽  
South America ◽  
East Asia ◽  
Parallel Evolution ◽  
Continental Drift ◽  
Maximum Correlation ◽  
The North ◽  
Extant Species ◽  
Land Mass ◽  
London Clay

The polarity of character states of pollen, leaf, endocarp, seed, perianth, androecium, and gynoecium within the Menispermaceae is established on the basis of maximum correlation of characters. Instances of parallel evolution are explained. The origin and spread of the different genera, which manifest the various combinations of character states, are analysed in the light of the position of the continents during the Cretaceous and Tertiary periods. Menispermaceae seem to have originated in the lowlands of Africa during the Cretaceous when South America, Africa, Madagascar, and India were close to one another. Consequent to the continental drift each land mass might have carried with it some elements of the primitive Menispermaceae which must have eventually given rise to the neoendemics. The Sino–Japanese spread of this family seems to have been post-Himalayan. "Malesia" appears to be a secondary centre of diversification of taxa derived from India. Cissampelos, Cocculus, and Stephania seem to have originated in India and entered Africa during the Miocene. The Eocene endocarps of North America show affinity with those of the London Clay, which in turn were probably derived from the African stock. Among the extant species of North America only Calycocarpum lyonii seems to be the relic of the North American Tertiary flora and the rest appear to have been derived from east Asia.

Symplocos Fruits from the Pliocene of Colombia

2021 ◽  
Vol 46 (2) ◽  
pp. 416-421
Author(s):  
Steven R. Manchester ◽  
Terry A. Lott ◽  
Fabiany Herrera ◽  
Henry Hooghiemstra ◽  
Vincent M. Wijninga ◽  
...  
Keyword(s):  
North America ◽  
South America ◽  
Middle Miocene ◽  
Late Eocene ◽  
The North ◽  
Extant Species ◽  
Molecular Phylogenetic ◽  
Voucher Specimens ◽  
Molecular Phylogenetic Data ◽  
Key Characters

Abstract— Fossil fruits of Symplocos (Ericales: Symplocaceae) are here recognized from the Pliocene of Guasca, Colombia, based on specimens formerly attributed to Cordia (Cordiaceae, Boraginales). Symplocos vera (Berry) comb. nov. is represented by 19 lignitized fruits. The fossils are recognized as belonging to Symplocos primarily by their woody endocarps that are apically truncate and that possess 3 to 5 apical germination pores and locules, and a central vascular canal extending the length of the endocarp. In several key characters they are highly congruent with the endocarps of the extant Neotropical clade S. ser. Symplocos. Some of the extant species in the series are variably 3- to 5-locular; 4-locular endocarps are otherwise rare in Symplocos, and 5-locular endocarps appear to be unique to this series. Symplocos vera is the only specifically named record of fossil Symplocos fruits with accessible voucher specimens from South America. The younger Neogene age of the fossils relative to those attributed to S. ser. Symplocos from the late Eocene of Texas, along with a report of Colombian fossil endocarps from the middle Miocene, supports the North America to South America migration inferred for this clade from molecular phylogenetic data.

scholarly journals Endemicity analysis of global Cretaceous dinosaurian faunas

1992 ◽  
Vol 6 ◽  
pp. 132-132
Author(s):  
Thomas R. Holtz
Keyword(s):  
North America ◽  
South America ◽  
Late Cretaceous ◽  
Late Jurassic ◽  
Continental Drift ◽  
Gobi Desert ◽  
Western Interior Seaway ◽  
Faunal Assemblages ◽  
Terrestrial Vertebrate ◽  
Herbivore Communities

It has often been assumed that the intensively studied dinosaur faunal assemblages of western North America and the Gobi Desert of Mongolia and China represent “typical” Late Cretaceous terrestrial vertebrate communities. This assumption has led to a paleoecological scenario in which a global ecological shift occurs from the dominance of high-browsing saurischian (i.e., sauropod) to low-browsing ornithischian (i.e., iguanodontian, marginocephalian, ankylosaurian) herbivore communities. Furthermore, the assumption that the Asiamerican dinosaur faunas are communities “typical” of the Late Cretaceous has forced the conclusion that the sauropod-dominated Argentine population must have been an isolated relict ecosystem of primitive taxa (i.e., titanosaurid sauropods, abelisaurid ceratosaurs). Recent discoveries and reinterpretations of other Late Cretaceous assemblages, however, seriously challenge these assumptions.Paleogeography and paleobiogeography have demonstrated that terrestrial landmasses became progressively fractionated from the Late Jurassic (Kimmeridgian-Tithonian) to the Late Cretaceous (Campanian), owing to continental drift and the development of large epicontinental seas (the Western Interior Seaway, the Turgai Sea, etc.). The Maastrichtian regressions resulted in the reestablishment of land connection between long isolated regions (for example, western and eastern North America). These geographic changes are reflected in changes in the dinosaurian faunas. These assemblages were rather cosmopolitan in the Late Jurassic (Morrison, Tendaguru, and Upper Shaximiao Formations) but became more provincialized throughout the Cretaceous.Cluster analysis of presence/absence data for the theropod, sauropod, and ornithischian clades indicates that previous assumptions for Late Cretaceous dinosaurian paleoecology are largely in error. These analyses instead suggest that sauropod lineages remained a major faunal component in both Laurasia (Europe, Asia) and Gondwana (South America, Africa, India, and Australia). Only the pre-Maastrichtian Senonian deposits of North America were lacking sauropodomorphs. Furthermore, the abelisaurid/titanosaurid fauna of Argentina is, in fact, probably more typical of Late Cretaceous dinosaurian communities. Rather, it is the coelurosaurian/ornithischian communities of Asiamerica (and particularly North America) that are composed primarily of dinosaurs of small geographic distribution. Thus, the Judithian, Edmontonian, and Lancian faunas, rather than being typical of the Late Cretaceous, most likely represent an isolated island-continent terrestrial vertebrate population, perhaps analogous to the extremely isolated vertebrate communities of Tertiary South America. Furthermore, the shift from high-browsing to low-browsing herbivore “dynasties” more likely represents a local event in Senonian North America and does not represent a global paleoecological transformation of Late Cretaceous dinosaur community structure.

scholarly journals Migration of exotic species of ammonites during highstands of sea level

1992 ◽  
Vol 6 ◽  
pp. 324-324
Author(s):  
Keith Young
Keyword(s):  
North America ◽  
South America ◽  
Exotic Species ◽  
Sea Level ◽  
South Atlantic ◽  
Horn Of Africa ◽  
Mozambique Channel ◽  
The North ◽  
North And South ◽  
Early Late

In northeastern Chihuahua and Trans-Pecos Texas, in the early Late Albian zone of Hysteroceras varicosum occurs the Boeseites romeri (Haas) fauna with B. romeri (Hass), B. perarmata (Hass), B. aff. barbouri (Haas), B. cf. howelli (Haas), B.proteus (Haas), Prohysteroceras cf. P. hanhaense Haas, Elobiceras sp., and Dipoloceras (?) sp. B. perarmata has also been collected at Cerro Mercado, near Monclova, Coahuila. Haas originally described this fauna from Angola. Now, from rocks in the same zone in the Sierra Mojada, Coahuila, Mexico, there is a form related to if not identical with Hysteroceras famelicum Van Hoepen, also originally described from Angola and also from the zone of Hysteroceras varicosum.These fossils are known only from southern North America and Angola; they have not been described from the European Tethys. In 1984 I suggested that during the highstand of sea level of the early Late Albian (Hysteroceras varicosum zone) these ammonites migrated from Angola to Mexico and Trans-Pecos Texas via an epeiric seaway extending across the sag between South America and Africa proposed by Kennedy and Cooper. This would be twelve to fifteen million years prior to an oceanic connection between the North and South Atlantic.I would now ask, can similar epeiric seas and highstands of sea level explain the migration of successive European, Tethyan, Jurassic ammonite faunas down the Mozambique Channel and around the horn of Africa into the Neuquen Basin of Argentina before Africa and Antarctica separated, as proposed by Spath.

scholarly journals Plastome Phylogenomic and Biogeographical Study on Thuja (Cupressaceae)

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Kole F. Adelalu ◽  
Xu Zhang ◽  
Xiaojian Qu ◽  
Jacob B. Landis ◽  
Jun Shen ◽  
...  
Keyword(s):  
North America ◽  
East Asia ◽  
Potential Effect ◽  
Molecular Dating ◽  
Disjunct Distribution ◽  
Land Bridge ◽  
Biogeographic History ◽  
Extant Species ◽  
History Of ◽  
Phylogenomic Analyses

Investigating the biogeographical disjunction of East Asian and North American flora is key to understanding the formation and dynamics of biodiversity in the Northern Hemisphere. The small Cupressaceae genus Thuja, comprising five species, exhibits a typical disjunct distribution in East Asia and North America. Owing to obscure relationships, the biogeographical history of the genus remains controversial. Here, complete plastomes were employed to investigate the plastome evolution, phylogenetic relationships, and biogeographic history of Thuja. All plastomes of Thuja share the same gene content arranged in the same order. The loss of an IR was evident in all Thuja plastomes, and the B-arrangement as previously recognized was detected. Phylogenomic analyses resolved two sister pairs, T. standishii-T. koraiensis and T. occidentalis-T. sutchuenensis, with T. plicata sister to T. occidentalis-T. sutchuenensis. Molecular dating and biogeographic results suggest the diversification of Thuja occurred in the Middle Miocene, and the ancestral area of extant species was located in northern East Asia. Incorporating the fossil record, we inferred that Thuja likely originated from the high-latitude areas of North America in the Paleocene with a second diversification center in northern East Asia. The current geographical distribution of Thuja was likely shaped by dispersal events attributed to the Bering Land Bridge in the Miocene and subsequent vicariance events accompanying climate cooling. The potential effect of extinction may have profound influence on the biogeographical history of Thuja.

Ecogeography and the Great American Interchange

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 266-280 ◽  
Author(s):  
S. David Webb
Keyword(s):  
North America ◽  
South America ◽  
North American ◽  
Mammalian Fauna ◽  
The South ◽  
Land Bridge ◽  
Southern Mexico ◽  
The North ◽  
Land Mammal ◽  
The Impact

When the isthmian land bridge triggered the Great American Interchange, a large majority of land-mammal families crossed reciprocally between North and South America at about 2.5 Ma (i.e., Late Pliocene). Initially land-mammal dynamics proceeded as predicted by equilibrium theory, with roughly equal reciprocal mingling on both continents. Also as predicted, the impact of the interchange faded in North America after about 1 m.y. In South America, contrary to such predictions, the interchange became decidedly unbalanced: during the Pleistocene, groups of North American origin continued to diversify at exponential rates. Whereas only about 10% of North American genera are derived from southern immigrants, more than half of the modern mammalian fauna of South America, measured at the generic level, stems from northern immigrants. In addition, extinctions more severely decimated interchange taxa in North America, where six families were lost, than in South America, where only two immigrant families became extinct.This paper presents a two-phase ecogeographic model to explain the asymmetrical results of the land-mammal interchange. During the humid interglacial phase, the tropics were dominated by rain forests, and the principal biotic movement was from Amazonia to Central America and southern Mexico. During the more arid glacial phase, savanna habitats extended broadly right through tropical latitudes. Because the source area in the temperate north was six times as large as that in the south, immigrants from the north outnumbered those from the south. One prediction of this hypothesis is that immigrants from the north generally should reach higher latitudes in South America than the opposing contingent of land-mammal taxa in North America. Another prediction is that successful interchange families from the north should experience much of their phylogenetic diversification in low latitudes of North America before the interchange. Insofar as these predictions can be tested, they appear to be upheld.

THE BIOGEOGRAPHY OF CANADIAN GRYLLOPTERA AND ORTHOPTERA

1989 ◽  
Vol 121 (4-5) ◽  
pp. 389-424 ◽  
Author(s):  
V.R. Vickery
Keyword(s):  
North America ◽  
Fossil Record ◽  
Neotropical Region ◽  
Climatic Conditions ◽  
Land Bridge ◽  
Recent Immigrants ◽  
Extant Species ◽  
The World ◽  
Land Mass ◽  
Orthopteroid Insects

AbstractThe saltatorial orthopteroid insects did not originate in North America. Five avenues of entry were utilized in migration from other parts of the world. These were: (1) ancestral forms migrated to this region in Pangaean times when all continents formed a single land mass; (2) later in time, taxa migrated from Europe when Eurasia and North America were still joined, or later via an Atlantic land bridge; (3) ancestral forms migrated northward from the Neotropical region before the separation of the two continents or, much later, when the two continents became rejoined; (4) later arriving taxa entered North America during the Pleistocene via a Beringian land bridge; (5) some species are very recent immigrants, either because of the activities of man or by migration into Canadian territory from the south.The fossil record is very incomplete. It indicates past climatic conditions, but is of limited assistance concerning extant taxa.Pleistocene glaciation had a profound effect upon the distribution of extant species. Many species were forced to move southward to escape the advancing ice. Some species probably were eliminated. It is clear that most of the extant species have migrated northward since the recession of the Wisconsin glacier.

scholarly journals Seesawing of Winter Temperature Extremes between East Asia and North America

2021 ◽  
Vol 34 (11) ◽  
pp. 4423-4434
Author(s):  
Mi-Kyung Sung ◽  
Seok-Woo Son ◽  
Changhyun Yoo ◽  
Jaeyoung Hwang ◽  
Soon-Il An
Keyword(s):  
North America ◽  
East Asia ◽  
North Pacific ◽  
Winter Temperature ◽  
Cold Weather ◽  
Temperature Extremes ◽  
The North ◽  
Budget Analysis ◽  
Upper Level ◽  
The North Pacific

AbstractIn recent winters, there have been repeated observations of extreme warm and cold spells in the midlatitude countries. This has evoked questions regarding how winter temperature extremes are induced. In this study, we demonstrate that abnormally warm winter weather in East Asia can drive the onset of extremely cold weather in North America approximately one week forward. These seesawing extremes across the basin are mediated by the North Pacific Oscillation (NPO), one of the recurrent atmospheric patterns over the North Pacific. Budget analysis of the quasigeostrophic geopotential tendency equation shows that intense thermal advection over East Asia is able to trigger the growth of the NPO. Vorticity fluxes associated with the upper-level stationary trough then strengthen and maintain the NPO against thermal damping following the onset of the NPO. Differential diabatic heating accompanied by changes in circulation also positively contribute to the growth and maintenance of the NPO. These results imply that recurrent cold extremes, seemingly contrary to global warming, may be an inherent feature resulting from strengthening warm extremes.

The North American Chydorus faviformis (Cladocera, Chydoridae) and the honeycombed taxa of other continents

1987 ◽  
Vol 315 (1175) ◽  
pp. 353-402 ◽  
Keyword(s):  
North America ◽  
South America ◽  
Salt Water ◽  
Distinct Species ◽  
Resting Eggs ◽  
The Other ◽  
Careful Study ◽  
Long Distance ◽  
The North ◽  
Species Groups

The taxon Chydorus faviformis , described by Birge from North America in 1893, has been considered to occur also in Asia, Australia, and South America. However, careful study of populations from these regions has revealed that all represent different species, none of which is closely related to C. faviformis . The taxa described here are C. obscurirostris and C. opacus from Australia, C. obscurirostris tasekberae from Malaysia, C. sinensis from China, C.angustirostris from India, and C. parvireticulatus from South America. The taxon in Malaysia differs somewhat from the corresponding taxon in Australia, but cannot be characterized more closely until males and ephippial females become available. The taxa differ among themselves in number of meshes on the shell of parthenogenetic females, surface patterning within the meshes, shape of the rostrum and height of the mesh walls along the edge and near the tip of the rostrum, stoutness and length of the major seta on the inner distal lobe of trunklimb I, shape of the labral plate, and shape and armament of the postabdomen. Ephippial females all have a single resting egg. They differ in the extent of secondary thickenings of the surface network within the shell meshes and in the amount of pigment deposited in the region of the egg locule. Males are most important for separating the taxa, indicating how necessary they are for working out evolutionary similarities and differences. Unfortunately no males of the taxa from Malaysia, India, and South America have been available. For the others, C.faviformis sens. str. is unique in that it is the only taxon in which the male loses its honeycomb (that is, the raised walls of the meshes) on reaching maturity. It also has a sharp pre-anal angle and a marked narrowing of the postabdomen distad from here, which is the pattern typical of species in the Chydorus sphaericus complex. None of the other faviformis -like species share this characteristic. Because of the marked differences in morphology and in geographical distribution of the species in North America and in South America, it is certain that even during the glacial ages, when the northern C. faviformis would have been displaced farthest southward, there was no exchange of either taxon to the other continent. The taxon from Manáos, Brazil listed as C.faviformis in the Birge collection is the C. parvireticulatus reported from much farther south in Brazil and Argentina. In Australia and Asia, except for the uncertain distinctness of the taxon in Malaysia, all the other taxa are markedly separate from each other and hence give no evidence for transfer, as by resting eggs, between continents or even from one region to another on the same continent. All the taxa have been stable in their geographical occurrence for very long periods of time. In addition to the faviformis -like taxa present as distinct species in different regions or on different continents, there are many other species groups of chydorids that have different member species on each continent. One possible explanation of this similarity in gross morphology without any long-distance dispersal of resting eggs to accomplish it is that the various protospecies (corresponding to the species groups) had largely evolved before the original land mass broke up into the present continents and subcontinents. As the distances between the continents increased, the salt-water gaps would come to be impassable barriers to dispersal. Evolution of the isolates would then yield new species, all retaining m any of the features of the protospecies. Each such group from a single protospecies would form the species groups we are now just beginning to recognize.

scholarly journals High-resolution modeling the distribution of surface air pollutants and their intercontinental transport by a global tropospheric atmospheric chemistry source-receptor model (GNAQPMS-SM)

2021 ◽  
Author(s):  
Qian Ye ◽  
Jie Li ◽  
Xueshun Chen ◽  
Huansheng Chen ◽  
Wenyi Yang ◽  
...  
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
North America ◽  
East Asia ◽  
South Asia ◽  
North Pacific ◽  
Receptor Model ◽  
The North ◽  
Intercontinental Transport ◽  
The North Pacific

Abstract. Many efforts have been devoted to quantifying the impact of intercontinental transport on global air quality by using global chemical transport models with horizontal resolutions of hundreds of kilometers in recent decades. In this study, a global online air quality source-receptor model (GNAQPMS-SM) is designed to effectively compute the contributions of various regions to ambient pollutant concentrations. The newly developed model is able to quantify source-receptor (S-R) relationships in one simulation without introducing errors by nonlinear chemistry, which largely reduces the computation costs compared to the brute force method. We calculate the surface and planetary boundary layer (PBL) S-R relationships in 19 regions over the whole globe for ozone, black carbon (BC) and non-sea-salt sulphate (nss-sulphate) by conducting a high-resolution (0.5° × 0.5°) simulation for the year 2018. The model exhibits a realistic capacity in reproducing the spatial distributions and seasonal variations of tropospheric ozone, carbon monoxide, and aerosols at global and regional scales (Europe, North America and East Asia). The correlation coefficient (R) and normalized mean bias (NMB) for seasonal ozone at global background and urban-rural sites ranged from 0.49 to 0.87 and −2 % to 14.97 %, respectively. For aerosols, the R and NMB in Europe, North America and East Asia mostly exceed 0.6 and are within ±15 %. These statistical parameters based on this global simulation can match those of regional models in key regions. The simulated tropospheric nitrogen dioxide and aerosol optical depths are generally in agreement with satellite observations. The model overestimates ozone mixing ratios in the upper troposphere and stratosphere in the tropics, mid-latitude and polar regions of the Southern Hemisphere due to the use of a simplified stratospheric ozone scheme and/or biases in estimated stratosphere-troposphere exchange dynamics. We find that O3 in the surface layer can travel a long distance and contributes a nonnegligible fraction to downwind regions. Nonlocal source transport explains approximately 35–60 % of surface O3 in East Asia, South Asia, Europe and North America. The O3 exported from Europe can also be transported across the Arctic Ocean to the North Pacific and contributes nearly 5–7.5 % to the North Pacific. BC, as a primary aerosol, is directly linked to local emissions, and each BC source region mainly contributes to itself and surrounding regions. For nss-sulphate, contributions of long-range transport account for 15–30 % within the PBL in East Asia, South Asia, Europe and North America. Our estimated international transport is lower than that from the Hemispheric Transport of Air Pollution (HTAP) assessment report in 2010. In this study, local contributions to surface nss-sulphate and BC exceed the ranges given in the HTAP model, while local contributions to nss-sulphate and BC within the PBL are mainly within the ranges. This difference may be related to the different simulation years, emission inventories, horizontal resolutions and S-R revealing methods. The S-R relationship of aerosols within the East Asia subcontinent is also assessed. The model that we developed creates a link between the scientific community and policymakers. Finally, the results are discussed in the context of future model development and analysis opportunities.

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