Intercontinental disjunctions between eastern Asia and western North America in vascular plants highlight the biogeographic importance of the Bering land bridge from late Cretaceous to Neogene

This review shows a close biogeographic connection between eastern Asia and western North America from the late Cretaceous to the late Neogene in major lineages of vascular plants (flowering plants, gymnosperms, ferns and lycophytes). Of the eastern Asian–North American disjuncts, conifers exhibit a high proportion of disjuncts between eastern Asia and western North America. Several lineages of ferns also show a recent disjunct pattern in the two areas. In flowering plants, the pattern is commonly shown in temperate elements between northeastern Asia and northwestern North America, as well as elements of the relict boreotropical and Neogene mesophytic and coniferous floras. The many cases of intercontinental biogeographic disjunctions between eastern Asia and western North America in plants supported by recent phylogenetic analyses highlight the importance of the Bering land bridge and/or the plant migrations across the Beringian region from the late Cretaceous to the late Neogene, especially during the Miocene. The Beringian region has permitted the filtering and migration of certain plant taxa since the Pliocene after the opening of the Bering Strait, as many conspecific taxa or closely related species occur on both sides of Beringia.     

Molecular phylogenetic systematics and biogeography of tribe Neillieae (Rosaceae) using DNA sequences of cpDNA, rDNA, and LEAFY

A phylogeny of the tribe Neillieae (Rosaceae), which comprises Neillia, Stephanandra, and Physocarpus, was reconstructed based on nucleotide sequences of several regions of cpDNA, the ITS and ETS regions of rDNA, and the second intron of LEAFY, to elucidate relationships among genera and species in Neillieae and to assess the historical biogeography of the tribe. Phylogenetic analyses indicated that Physocarpus and Neillia-Stephanandra were strongly supported as monophyletic and suggested that Stephanandra may have originated by hybridization between two lineages of Neillia. Dispersal-vicariance analyses suggested that the most recent common ancestor of Neillieae may have occupied eastern Asia and western North America and that Physocarpus and Neillia-Stephanandra may have been split by an intercontinental vicariance event in the early Miocene. The biogeographic analyses also suggested that species of Neillia and Stephanandra diversified in eastern Asia, whereas in Physocarpus one dispersal event from western North America to eastern Asia occurred. Two divergent types of LEAFY sequences were found in the eastern North American species, P. opulifolius, but only one type was present in each plant. The two types of sequences may represent homeologous genes that originated by hybridization between P. capitatus and P. monogynus, both western North American species.     

紫荆属的系统发育和生物地理学研究

紫荆属（Cercis L.）约含8种,间断分布于亚洲东、西部、欧洲南部和北美。应用核糖体DNA的ITS基因序列研究紫荆属的系统发育关系。在最简约性分析,北美的两个种和南欧、西亚的一个种构成一单系群而隐藏于东亚的种类中。这表明紫荆属北美的种类和南欧、西亚的种类之间的关系比它们的各自与东亚的种类的关系要密切。研究还发现北美洲东、西部的种类可能具较近亲缘。紫荆属以白令陆桥或北大西洋陆桥为迁移途径的可能性似乎都不能排除;北半球的生物地理分布式样可具有复杂的起源。     

Molecular phylogeny of Anaphalis (Asteraceae, Gnaphalieae) with biogeographic implications in the Northern Hemisphere

Anaphalis is the largest Asian genus in the tribe Gnaphalieae (Asteraceae) and has its greatest species diversity in the eastern Himalayas. The nuclear internal and external transcribed spacers were sequenced for Anaphalis species, with an emphasis on the eastern Himalayan taxa to examine the monophyly and construct the phylogenetic relationships of and within the genus. The results suggest that all species of Anaphalis are nested with Helichrysum, showing a close relationship with a Mediterranean–Asian group of Helichrysum. Although the monophyly of Anaphalis is only weakly supported, two clades within the genus are well recognized, each consisting of two subgroups. The inferred phylogenetic relationships within Anaphalis correspond to the shape of leaf base, rather than the morphology of the capitula and phyllaries that are usually used for species delimitation and classification in the genus. All four subgroups of Anaphalis are common and diversified in the eastern Himalayas with multiple dispersals out of this region. The sole North American species of Anaphalis is best hypothesized to be the result of long-distance dispersal or overland migration via Bering land bridge from Asia. Our analyses suggest that the extant distribution of Anaphalis has most likely resulted one radiation into the eastern Himalayas followed by repeated independent dispersals and/or radiations mostly into eastern Asia but also into the western Himalayas, North America, and southeast Asia.     

Reticulate evolution in Thuja inferred from multiple gene sequences: implications for the study of biogeographical disjunction between eastern Asia and North America

The eastern Asia-North America disjunction is one of the most interesting biogeographical patterns, but its formation is still in much debate. Here nucleotide sequences of five cpDNA regions, nrDNA ITS and two low-copy nuclear genes (LEAFY, 4CL) were employed to reconstruct the phylogeny and to explore the historical biogeography of Thuja, a typical eastern Asia-North America disjunct genus. High topological discordance was observed between chloroplast and nuclear gene trees, even between different nuclear gene trees, suggesting that Thuja could have a reticulate evolutionary history due to multiple interspecific hybridization events. The eastern Asian species Thuja koraiensis might have obtained its chloroplast genome from the eastern North American species T. occidentalis by chloroplast capture, while the western North American species T. plicata is very likely to have inherited a recombinant cpDNA. Based on the phylogenetic analysis of multiple genes, DIVA-reconstruction of the distribution history, molecular clock estimation and fossil data, we inferred that Thuja could have originated from the high-latitude areas of North America in the Paleocene or earlier with subsequent expansion into eastern Asia through the Bering Land Bridge. The two eastern Asia species T. standishii and T. sutchuenensis have a sister relationship, and their split could have occurred in the Oligocene or early Miocene. In the present study, the selection of molecular markers in biogeographic studies was also discussed. Since most previous studies on the eastern Asia and North America disjunction are based on uniparentally inherited cpDNA and (or) directly sequenced nrDNA ITS data, the historical reticulate evolution in the studied groups might have been underestimated. Therefore, we suggest that multiple genes from different genomes, especially low-copy nuclear genes, be used in this research area in the future.     

Phylogeny and biogeography of the flowering plant genus Styrax (Styracaceae) based on chloroplast DNA restriction sites and DNA sequences of the internal transcribed spacer region

Phylogenetic relationships within the flowering plant genus Styrax were investigated with DNA sequence data from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) and with chloroplast DNA restriction site data from the genes trnK, rpoC1, and rpoC2. The data sets from each genome were analyzed separately and in combination with parsimony methods. The results strongly support the monophyly of each of the four series of the genus but provide little phylogenetic resolution among them. Reticulate evolution may at least partly explain discordance between the molecular phylogenetic estimates and a prior morphological estimate within series Cyrta. The historical biogeography of the genus was inferred with unweighted parsimony character optimization of trees recovered from a combined ITS and morphological data set, after a series of combinability tests for data set congruence was conducted. The results are consistent with the fossil record in supporting a Eurasian origin of Styrax. The nested phylogenetic position of the South American members of the genus within those from southern North America and Eurasia suggests that the boreotropics hypothesis best explains the amphi-Pacific tropical disjunct distribution occurring within section Valvatae. The pattern of relationship recovered among the species of section Styrax ((western North America + western Eurasia) (eastern North America + eastern Eurasia)) is rare among north-temperate Tertiary forest relicts. The monophyly of the group of species from western North America and western Eurasia provides qualified support for the Madrean-Tethyan hypothesis, which posits a Tertiary floristic connection among the semiarid regions in which these taxa occur. A single vicariance event between eastern Asia and eastern North America accounts for the pattern of relationship among intercontinental disjuncts in series Cyrta.     

Phylogenetic assessment and biogeographic analyses of tribe <Emphasis Type="Italic">Peracarpeae</Emphasis> (Campanulaceae)

Peracarpeae is a small tribe consisting of three genera: Homocodon, Heterocodon and Peracarpa, with a disjunct distribution between eastern Asia and western North America. Homocodon is endemic to southwestern China and was previously placed in the western North American genus Heterocodon. Our phylogenetic analysis using four plastid markers (matK, atpB, rbcL and trnL-F) suggests the polyphyly of Peracarpeae. Homocodon is sister to a clade consisting of the eastern Asian Adenophora, Hanabusaya and species of Campanula from the Mediterranean region and North America, rather than forming a clade with Heterocodon. Homocodon and its Eurasia relatives are estimated to have diverged in the early Miocene (16.84 mya, 95% HPD 13.35–21.45 mya). The eastern Asian Peracarpa constitutes a clade with the North American Heterocodon, Githopsis and three species of Campanula, supporting a disjunction between eastern Asia and North America in Campanulaceae. The Asian-North American disjunct lineages diverged in the early Miocene (16.17 mya, 95% HPD 13.12–20.9 mya). The biogeographic analyses suggest that Homocodon may be a relict of an early radiation in eastern Asia, and that Peracarpa and its closest North American relatives most likely originated from a Eurasian ancestor.     

Phylogeny and Biogeography of Thuja L. (Cupressaceae), an Eastern Asian and North American Disjunct Genus

In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNA ITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Carr. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.     

Molecular phylogeny of the harvestmen genus Sabacon (Arachnida: Opiliones: Dyspnoi) reveals multiple Eocene–Oligocene intercontinental dispersal events in the Holarctic

We investigated the phylogeny and biogeographic history of the Holarctic harvestmen genus Sabacon, which shows an intercontinental disjunct distribution and is presumed to be a relatively old taxon. Molecular phylogenetic relationships of Sabacon were estimated using multiple gene regions and Bayesian inference for a comprehensive Sabacon sample. Molecular clock analyses, using relaxed clock models implemented in BEAST, are applied to date divergence events. Biogeographic scenarios utilizing S-DIVA and Lagrange C++ are reconstructed over sets of Bayesian trees, allowing for the incorporation of phylogenetic uncertainty and quantification of alternative reconstructions over time. Four primary well-supported subclades are recovered within Sabacon: (1) restricted to western North America; (2) eastern North American S. mitchelli and sampled Japanese taxa; (3) a second western North American group and taxa from Nepal and China; and (4) eastern North American S. cavicolens with sampled European Sabacon species. Three of four regional faunas (wNA, eNA, East Asia) are thereby non-monophyletic, and three clades include intercontinental disjuncts. Molecular clock analyses and biogeographic reconstructions support nearly simultaneous intercontinental dispersal coincident with the Eocene–Oligocene transition. We hypothesize that biogeographic exchange in the mid-Tertiary is likely correlated with the onset of global cooling, allowing cryophilic Sabacon taxa to disperse within and among continents. Morphological variation supports the divergent genetic clades observed in Sabacon, and suggests that a taxonomic revision (e.g., splitting Sabacon into multiple genera) may be warranted.     

Phylogenetic relationships and evolution in Chrysosplenium (Saxifragaceae) based on matK sequence data

Chrysosplenium (Saxifragaceae) consists of 57 species widely distributed in temperate and arctic regions of the Northern Hemisphere, with two species restricted to the southern part of South America. Species relationships within the genus are highly problematic. The genus has traditionally been divided into two groups, sometimes recognized as sections (Oppositifolia and Alternifolia), based on leaf arrangement, or, alternatively, into 17 series. Based on morphological features, Hara suggested that the genus originated in South America and then subsequently migrated to the Northern Hemisphere. We conducted phylogenetic analyses of DNA sequences of the chloroplast gene matK for species of Chrysosplenium to elucidate relationships, test Hara's biogeographic hypothesis for the genus, and examine chromosomal and gynoecial diversification. These analyses revealed that both sections Oppositifolia and Alternifolia are monophyletic and form two large sister clades. Hence, leaf arrangement is a good indicator of relationships within this genus. Hara's series Pilosa and Macrostemon are each also monophyletic; however, series Oppositifolia, Alternifolia, and Nepalensia are clearly not monophyletic. MacClade reconstructions suggest that the genus arose in Eastern Asia, rather than in South America, with several independent migration events from Asia to the New World. In one well-defined subclade, species from eastern and western North America form a discrete clade, with Old World species as their sister group, suggesting that the eastern and western North American taxa diverged following migration to that continent. The South American species forms a clade with species from eastern Asia; this disjunction may be the result of ancient long-distance dispersal. Character mapping demonstrated that gynoecial diversification is dynamic, with reversals from inferior to half-inferior ovaries, as well as to ovaries that appear superior. Chromosomal evolution also appears to be labile with several independent origins of n = 12 (from an original number of n = 11) and multiple episodes of aneuploidy.     

ELECTROPHORETIC ENZYME ANALYSIS OF NORTH AMERICAN AND EASTERN ASIAN POPULATIONS OF AGASTACHE SECT. AGASTACHE (LABIATAE)

Agastache sect. Agastache consists of seven species in North America and one disjunct in eastern Asia. Starch-gel electrophoresis of enzymatic proteins was employed to assess genetic relationships among these species and to estimate the amount of genetic divergence between the North American and Asian populations. Species of the western United States appear to be better adapted for outcrossing than are the others and are much more genetically variable, with higher levels of heterozygosity per individual, more alleles per species, and higher percentages of polymorphic loci per population. Nonmetric multidimensional scaling of Nei's genetic distances among 32 populations partitioned the section into four discrete groups: 1) A. nepetoides (eastern North America), 2) A. scrophulariifolia and A. foeniculum (eastern and central North America), 3) the four species of the western United States (A. urticifolia, A. occidentalis, A. parvifolia and A. cusickii) and 4) A. rugosa (eastern Asia). Asian Agastache, separated from its American congeners for over twelve million years, differed from American populations at two of fifteen loci surveyed. Nei's genetic distances between Asian and North American populations ranged from 0.2877 to 0.6734.     

Integrated Fossil and Molecular Data Reveal the Biogeographic Diversification of the Eastern Asian-Eastern North American Disjunct Hickory Genus (Carya Nutt.)

The hickory genus (Carya) contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51) Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.     

ORIGIN AND BIOGEOGRAPHY OF AESCULUS L. (HIPPOCASTANACEAE): A MOLECULAR PHYLOGENETIC PERSPECTIVE

Sequences of chloroplast gene matK and internal transcribed spacers of nuclear ribosomal RNA genes were used for phylogenetic analyses of Aesculus, a genus currently distributed in eastern Asia, eastern and western North America, and southeastern Europe. Phylogenetic relationships inferred from these molecular data are highly correlated with the geographic distributions of species. The identified lineages closely correspond to the five sections previously recognized on the basis of morphology. Ancestral character-state reconstruction, a molecular clock, and fossil evidence were used to infer the origin and biogeographic history of the genus within a phylogenetic framework. Based on the molecular phylogenetic reconstruction of the genus, sequence divergence, and paleontological evidence, we infer that the genus originated during the transition from the Cretaceous to the Tertiary (~65 M.Y.B.P.) at a high latitude in eastern Asia and spread into North America and Europe as an element of the “boreotropical flora”; the current disjunct distribution of the genus resulted from geological and climatic changes during the Tertiary.     

Phylogeny and biogeography of Altingiaceae: evidence from combined analysis of five non-coding chloroplast regions

The Altingiaceae consist of approximately 15 species that are disjunctly distributed in Asia and North America. The genus Liquidambar has been employed as a biogeographic model for studying the Northern Hemisphere intercontinental disjunctions. Parsimony and Bayesian analyses based on five non-coding chloroplast regions support that (1) Liquidambar is paraphyletic; (2) the temperate Liquidambar acalycina and Liquidambar formosana are nested within a large tropical to subtropical Asian clade; (3) Semiliquidambar is scattered in the eastern Asian clade and is of hybrid origin involving at least two maternal species: L. formosana and L. acalycina; and (4) the eastern North American Liquidambar styraciflua groups with the western Asian Liquidambar orientalis, but is highly distinct from other lineages. Biogeographically, our results demonstrate the complexity of biogeographic migrations throughout the history of Altingiaceae since the Cretaceous, with migration across both the Bering and the North Atlantic land bridges.     

几种石耳科地衣生物地理学关系的分子评估(英文)

对具有北美东部和亚洲东部近缘生物地理学关系的大型地衣种类进行系统发育检测较少。笔者获得了石耳科中8个种10个样本nrDNA的ITS完整序列,并对本科中在分布上具有重要意义的4个种的生物地理学关系进行了分析和评估。通过对细胞核核糖体DNA变异性较强的ITS段碱基序列的比较分析,支持放射盘石耳(Umbilicaria muehlenbergii)、宾州疱脐衣(Lasallia pennsylvanica)为同种型间断分布,美味石耳(U.escu-lenta)和大叶石耳(U.mammulata)间已经达到了相当高的分化程度,为异种型间断分布。地理学分析显示该两种石耳的分化可能是由于太平洋的扩展和隔离所造成的结果。同种型间断分布种类的不同地区的样本之间的差异较小。推测了不同类型间断分布种类的分化时间,美味石耳与大叶石耳的分化发生在中新世(23～5.33 Mya)中期,白令海峡形成期间。     

Anatomically preserved Liquidambar (Altingiaceae) from the middle Miocene of Yakima Canyon, Washington state, USA, and its biogeographic implications

Liquidambar changii Pigg, Ickert-Bond & Wen sp. nov. (Altingiaceae) is established for anatomically preserved, middle Miocene infructescences from Yakima Canyon, Washington, USA. Specimens are spherical, ～2.5 cm in diameter, and have ～25-30 tightly packed, bilocular fruits per head. Fruits are 3.4-4.7 mm wide × 2.6-3.5 mm long and wedge shaped, fused at the base, and free distally. Each locule contains 1-2 mature, elongate seeds proximally and 5-9 aborted seeds of more irregular shape distally. Mature seeds are 1.5 mm long × 1.2 mm wide, elongate, and triangular transversely, with a slight flange. Seeds have a seed coat for which three zones can be well defined, a uniseriate outer palisade layer, a middle region of isodiametric cells comprising most of the integument, and a uniseriate inner layer of tangentially elongate cells lining the embryo cavity. Liquidambar changii is most similar to the eastern Asian L. acalycina H.-T. Chang on features of infructescence, fruit, and seed morphology and quite unlike the North American L. styraciflua L. and other species. Such a close relationship between these two species supports a Beringian biogeographic track between eastern Asia and western North America during the Miocene. Previous phylogenetic and allozyme analysis of modern Liquidambar demonstrates a close relationship between North American-western Asian taxa and suggests a North Atlantic biogeographic track in the middle Miocene. Together, these biogeographic tracks underscore the complexity of the biogeographic history of the Altingiaceae in the Northern Hemisphere throughout the Neogene.     

Phylogeny and Biogeography of Thuja L. （Cupressaceae）, an Eastern Asian and North American Disjunct Genus

In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNAITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Cart. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.     

Molecular systematics and biogeography of Wisteria inferred from nucleotide sequences of nuclear and plastid genes

Previous molecular phylogenetic studies of Fabaceae indicated that species of Wisteria, an intercontinental disjunct genus between eastern Asia and eastern North America, formed a clade derived from within Callerya. However, interspecific relationships were not well resolved or supported. In this study, we used sequences of the nuclear ribosomal DNA internal transcribed spacer region and the chloroplast gene matK to examine interspecific relationships and explore implications of the phylogeny for the systematics and biogeography of Wisteria. Our results showed that Wisteria with deciduous leaves and racemose inflorescences formed a strongly supported clade derived from within the paraphyletic Callerya. Afgekia was also found to be included within Callerya. Therefore, our data support the merger ofAfgekia, Callerya, and Wisteria. The phylogenetic pattern suggested that the deciduousness in Wisteria may be a derived trait likely in response to temperate climate, and the racemose inflorescences in the Afgekia–Callerya–Wisteria clade may have evolved from panicles. Our study also provided strong support for the sister relationship of the North American and eastern Asian species of Wisteria. In the Asian clade, Wisteria brachybotrys Siebold & Zucc. of Japan was sister to the clade containing W. floribunda (Willd.) DC of Japan and Korea, and W. sinensis (Sims) Sweet of China. However, our data offered weak support for the sister relationship ofW. floribunda and W. sinensis. Our divergence time and biogeographic analyses suggested that the eastern Asian–North American disjunction in Wisteria may have occurred through a dispersal event in the middle Miocene (13.4 Mya) from the Old World to the New World across the Bering land bridge followed by vicariance in the late Miocene (6.8 Mya). This study added another example to the “out of Asia” migration for the eastern Asian–eastern North American disjunction.     

湖南参属的归并及亚洲楤木属(五加科)的一个新种和一些名称的变更

分子与形态证据表明湖南参 (HunaniopanaxhypoglaucusC .J.Qi&T .R .Cao)起源于木属 (AraliaL .) ,湖南参的近缘种为寄生五叶参 (Araliaparasitica)和轮伞五叶参 (Araliaverticillata) ,形态证据支持湖南参为轮伞五叶参的姐妹种 ,此 2种具轮伞花序这一共衍征。为了保证木属的单系性 ,现将湖南参并入木属 ,并作如下新组合 :Araliahypoglauca (C .J .Qi&T .R .Cao)J.Wen&Y .F .Deng .本文报道了湖南参在广西的新分布。目前的形态学和分子数据均不支持早先提出的湖南参与树参属 (Dendropanax)的近缘关系。本文亦报道了木属的 1新种、 2新种组合和 1个新名称 :AraliashangianaJ .Wen .sp .nov .(向氏五叶参 ,新种 ) ;Araliaglabrifoliolata (C .B .Shang)J .Wen .comb .nov . (光叶五叶参 ,新组合 ) ;Araliastellata (King)J.Wen ,comb .nov . (星毛羽叶参 ,新组合 )和AraliadelavayiJ .Wen .nom .nov .(云南五叶参 ,新名称 )。     

Amphisbaenian paleobiogeography: Evidence of vicariance and geodispersal patterns

Paleobiogeographic patterns within the Amphisbaenia were evaluated using the modified Brooks Parsimony Analysis (BPA) and recently published morphological and molecular phylogenies. Extant amphisbaenians are present in Africa, South America, North America, Europe, and the Middle East. The modified BPA was used to determine the relative effects of Pangean breakup, sea-level change, and climate change on evolutionary and distributional patterns within the Amphisbaenia. The modified BPA also tested the biogeographic effect of the Rhineuridae's phylogenetic position as either most basal in the morphologic phylogeny or most derived in the molecular phylogeny. The morphological and molecular analyses resulted in two different biogeographic hypotheses. The morphological analysis indicated three major biogeographic regions for the Amphisbaenia: 1) Africa, South America, and the Caribbean, 2) western Asia, and 3) North America. The molecular analysis indicated two major biogeographic regions: 1) Africa, western Asia, and North America, and 2) South America. The morphological biogeographic pattern corresponds with the known timing of the breakup of Pangea and the resulting paleogeographic reconstructions of the Mesozoic and Early Cenozoic. While the molecular pattern is similar to patterns recovered from dinosaurian biogeographic studies, the closer connection of Africa with North America rather than South America does not match well-constrained geologic evidence for the sequence of Pangean breakup. Both paleobiogeographic analyses, however, resulted in congruent patterns of speciation through vicariance and geodispersal. This suggests that in addition to the breakup of Pangea, such cyclical Earth history processes as sea-level and climate changes played an important role in the biogeographic patterns of the Amphisbaenia.