A classification of the genus Nothofagus (Fagaceae)

PHILIPSON, W. R. & PHILIPSON, M. N., 1988. A classification of the genus Nothofagus (Fagaceae). The genus Nothofagus is subdivided into two subgenera, two sections and three subsections, employing characters of the pollen, cupule and vernation, together with the incidence of leaf-fall. The subdivision into subgenera also agrees with present geographical distribution and with characters of the secondary xylem. One subgeneric and one subsectional name are new. Reasons are given for departures from previous classifications.     

Diversity of turtles across the cretaceous/tertiary boundary in Northeastern Montana

The abundant chelonian faunas of the Hell Creek and Tullock formations of McCone and Garfield counties, Montana, span the Cretaceous/Tertiary boundary and provide a basis for assessing extinction and changes in diversity. Over three thousand specimens were counted on a modified minimum number basis from 510 localities. The Lancian (Maastrichtian) part of the Hell Creek Formation contains at least 19 genera and subgenera of turtles and probably a greater but undetermined number of species and comprises the most diverse fossil turtle fauna known from a single rock unit. At least 15 generic level taxa survive into the Puercan (early Paleocene) part of the overlying Tullock Formation and only one new genus appears. The magnitude of the change in diversity across the Cretaceous/Tertiary boundary is less than or compaable to examples within the Tertiary and is readily explained by moderate ecological changes.     

Nothofagus: Evolution from a southern perspective

Nothofagus holds a premier position in the study of Southern Hemisphere plant evolution and biogeography, and many have attempted to reconstruct its history. A recent surge of research on both living and fossil species has added valuable data to the debate, but has also introduced complications, including the now less certain familial relationships of the genus. The vast quantity of fossil evidence provides an extremely firm base for reconstruction of the past distribution of Nothofagus, and allows informed speculation on the time and places of origin and major speciation events.     

Phylogeny of Cyttaria inferred from nuclear and mitochondrial sequence and morphological data

Cyttaria species (Leotiomycetes, Cyttariales) are obligate, biotrophic associates of Nothofagus (Hamamelididae, Nothofagaceae), the southern beech. As such Cyttaria species are restricted to the southern hemisphere, inhabiting southern South America (Argentina and Chile) and southeastern Australasia (southeastern Australia including Tasmania, and New Zealand). The relationship of Cyttaria to other Leotiomycetes and the relationships among species of Cyttaria were investigated with newly generated sequences of partial nucSSU, nucLSU and mitSSU rRNA, as well as TEF1 sequence data and morphological data. Results found Cyttaria to be defined as a strongly supported clade. There is evidence for a close relationship between Cyttaria and these members of the Helotiales: Cordierites, certain Encoelia spp., Ionomidotis and to a lesser extent Chlorociboria. Order Cyttariales is supported by molecular data, as well as by the unique endostromatic apothecia, lack of chitin and highly specific habit of Cyttaria species. Twelve Cyttaria species are hypothesized, including all 11 currently accepted species plus an undescribed species that accommodates specimens known in New Zealand by the misapplied name C. gunnii, as revealed by molecular data. Thus the name C. gunnii sensu stricto is reserved for specimens occurring on N. cunninghamii in Australia, including Tasmania. Morphological data now support the continued recognition of C. septentrionalis as a species separate from C. gunnii. Three major clades are identified within Cyttaria: one in South America hosted by subgenus Nothofagus, another in South America hosted by subgenera Nothofagus and Lophozonia, and a third in South America and Australasia hosted by subgenus Lophozonia, thus producing a non-monophyletic grade of South American species and a monophyletic clade of Australasian species, including monophyletic Australian and New Zealand clades. Cyttaria species do not sort into clades according to their associations with subgenera Lophozonia and Nothofagus.     

Endemism in Tasmanian cool temperate rainforest: alternative hypotheses

Endemism in Tasmanian cool temperate rainforest: alternative hypotheseS. Evidence is presented which suggests that hypotheses presented by Kirkpatrick & Brown relating to endemic species in Tasmania are either invalid or of limited importance for woody rainforest species.
In their place three hypotheses are presented to account for the presence of endemic species in Tasmanian cool temperate rainforest on the basis of the fossil record and the distribution of species which are closely related to the endemics. The first two hypotheses relate to the presence of the endemic species in the general Tasmanian region. They are:

• 1. 

  Some species evolved in southeastern Australia during the Tertiary in response to the changing climate. Some of the ancestral species still occur in temperate rainforest at lower latitudes in Australia.
• 2. 

  Some species have remained essentially unchanged in Tasmania during the Tertiary and Quaternary climatic changes.

The third hypothesis relates to the restriction of these cool temperate rainforest species to Tasmania:

• 1. 

  Post-glacial climatic changes (especially a decrease in rainfall) and the human influence (especially land clearing and fire) may have combined to eliminate some cool temperate rainforest species from mainland Australia.

     

Nothofagus Biogeography Revisited with Special Emphasis on the Enigmatic Distribution of Subgenus Brassospora in New Caledonia

Dispersals versus vicariance events and the presence of subgenus Brassospora in New Caledonia are two riddles of Nothofagus biogeography, a genus also distributed in New Guinea, New Zealand, South America, Southeast Australia, and Tasmania. Within a cladistic framework using the software COMPONENT 2.0, we demonstrate that most parsimonious area cladograms (areagrams) sensu cladistic biogeography need not always be the most plausible explanation nor reflect alternative geological hypotheses. The most parsimonious Nothofagus history sensu historical biogeography is reconstructed where a minimum of dispersed taxa is hypothesized and vicariance events are identified. A fully resolved well-established Nothofagus phylogeny was reconciled with three geological hypotheses (geograms) of East Gondwana break-up: (a) the conventional view, (b) an Australian—New Caledonian relationship, and (c) a biotic interchange between New Guinea and New Caledonia. Fossils determined to subgenus were optimized to the predicted lineages in the reconciled tree. Due to extensive extinctions, a maximum of three vicariance events are inferred, all being basal in the subgenera, an indication of subgeneric diversification prior to the break-up of Gondwana. Two taxa, N. gunnii and N. menziesii, are hypothesized as being long-distance dispersed. The most parsimonious solution suggests a close relationship between New Guinea and New Caledonia, supporting a Brassospora colonization route, but this hypothesis fails to predict numerous extinct lineages observed in the fossil record and thus must be rejected. The traditional break-up sequence of Gondwana is not the most parsimonious solution, indicating one incongruent node, but causes no overall incongruence with the fossil record. Considering all parameters, the occurrence of Brassospora in New Caledonia is most parsimoniously explained as a single colonization event from New Zealand where the subgenus subsequently went extinct in the Pliocene.     

Cophylogeny and biogeography of the fungal parasite Cyttaria and its host Nothofagus, southern beech

The obligate, biotrophic association among species of the fungal genus Cyttaria and their hosts in the plant genus Nothofagus often is cited as a classic example of cophylogeny and is one of the few cases in which the biogeography of a fungus is commonly mentioned or included in biogeographic analyses. In this study molecular and morphological data are used to examine hypotheses regarding the cophylogeny and biogeography of the 12 species of Cyttaria and their hosts, the 11 species of Nothofagus subgenera Lophozonia and Nothofagus. Our results indicate highly significant overall cophylogenetic structure, despite the fact that the associations between species of Cyttaria and Nothofagus usually do not correspond in a simple one to one relationship. Two major lineages of Cyttaria are confined to a single Nothofagus subgenus, a specificity that might account for a minimum of two codivergences. We hypothesize other major codivergences. Numerous extinction also are assumed, as are an independent parasite divergence followed by host switching to account for C. berteroi. Considering the historical association of Cyttaria and Nothofagus, our hypothesis may support the vicariance hypothesis for the trans-Antarctic distribution between Australasian and South American species of Cyttaria species hosted by subgenus Lophozonia. It also supports the hypothesis of transoceanic long distance dispersal to account for the relatively recent relationship between Australian and New Zealand Cyttaria species, which we estimate to have occurred 44.6-28.5 mya. Thus the history of these organisms is not only a reflection of the breakup of Gondwana but also of other events that have contributed to the distributions of many other southern hemisphere plants and fungi.     

松科早期球果研究的历史和现状

本文主要对早白垩世到老第三纪渐新世这段时间的松科化石球果的研究作了系统回顾和总结。松科化石球果的研究经历了一个由分散、幼稚到系统、成熟的发展过程,现在将松科化石球果分为三个属：Pityostrobus、Pseudoaraucaria 及Pinus。其中Pseudoaraucaria及Pinus为两个自然属,Pseudoaraucaria已经绝灭。Pityostrobus作为一个器官属,包括那些在松科中分类位置不明的球果。对松科化石球果进行细致的外部形态及内部结构的研究主要目的在于演化关系的探讨上：对于Pinus,主要探讨这个属内各个亚属、组、亚组之间的演化关系;对于Pityostrobus和Pseudoaraucaria,通过绝灭类型的分析,探索松科内各个类群(包括绝灭的)的演化关系进而完成进化树是研究的主要方向,现在这方面已有了Pinus中心说及Pseudoaraucaria分支说两个假说。     

Molecular phylogenetics and biogeography provide insights into the subgeneric classification of Wiedemannia Zetterstedt (Diptera: Empididae: Clinocerinae)

The subgenera of Wiedemannia are poorly defined and, as such, most recently described species are not assigned to a subgenus or have been assigned to a subgenus without explanation. In this study we perform a molecular phylogenetic analysis to elucidate relationships within the genus Wiedemannia. We sequenced two mitochondrial (cytochrome oxidase c subunit I and cytochrome β) and two nuclear (carbomoylphosphate synthase domain of rudimentary and elongation factor‐1α) gene fragments to reconstruct phylogenetic relationships among the subgenera Chamaedipsia, Eucelidia, Philolutra, Pseudowiedemannia, Roederella and Wiedemannia (s.s.) using both Bayesian inference and maximum likelihood approaches. The genus was found to be monophyletic, but most of the subgenera were not. We propose eliminating the present subgeneric division altogether. Molecular dating using a log‐normal clock model and calibration with fossil species indicated that Wiedemannia diversified about 48 Ma, while there was still land connectivity between Europe and Asia with North America. Wiedemannia has a near‐worldwide distribution apart from the Australasian and Neotropical regions and Antarctica, with greatest species richness in the western Palaearctic, especially the Mediterranean region. Molecular phylogenetics support more recent morphological studies. The subgenera of Wiedemannia are invalid and rejected. Biogeographical data suggest potential hotspots, and the current distribution is discussed.     

Not so ancient: the extant crown group of Nothofagus represents a post-Gondwanan radiation

This study uses a molecular-dating approach to test hypotheses about the biogeography of Nothofagus. The molecular modelling suggests that the present-day subgenera and species date from a radiation that most likely commenced between 55 and 40 Myr ago. This rules out the possibility of a reconciled all-vicariance hypothesis for the biogeography of extant Nothofagus. However, the molecular dates for divergences between Australasian and South American taxa are consistent with the rifting of Australia and South America from Antarctica. The molecular dates further suggest a dispersal of subgenera Lophozonia and Fuscospora between Australia and New Zealand after the onset of the Antarctic Circumpolar Current and west wind drift. It appears likely that the New Caledonian lineage of subgenus Brassospora diverged from the New Guinean lineage elsewhere, prior to colonizing New Caledonia.The molecular approach strongly supports fossil-based estimates that Nothofagus diverged from the rest of Fagales more than 84 Myr ago. However, the mid-Cenozoic estimate for the diversification of the four extant subgenera conflicts with the palynological interpretation because pollen fossils, attributed to all four extant subgenera, were widespread across the Weddellian province of Gondwana about 71 Myr ago. The discrepancy between the pollen and molecular dates exists even when confidence intervals from several sources of error are taken into account. In contrast, the molecular age estimates are consistent with macrofossil dates. The incongruence between pollen fossils and molecular dates could be resolved if the early pollen types represent extinct lineages, with similar types later evolving independently in the extant lineages.     

Fossil wood of Euphorbiaceae from the Tertiary of West Bengal,India

The paper describes a new species of fossil wood of Euphorbiaceae, Mallotoxylon cleidionoides sp. nov. from the Tertiary Laterites near Santiniketan, Birbhum District of West Bengal. The structure of the fossil wood closely resembles the wood anatomy of the extant genus Mallotus Lour. This is the first record of the occurrence of an euphorbiaceous wood from the Tertiary of West Bengal.     

Tertiary leaves of the tribe Banksieae (Proteaceae) from south-eastern Australia

Leaves from the tribe Banksieae of the Proteaceae are well represented in Tertiary deposits in south-eastern Australia. Four new species of Banksieaephyllum are erected, taking the total to 11, and two species are described in a new genus, with leaves with architectural similarities to the tribe Banksieae but without organic preservation. The fossil species demonstrate that the tribe was diverse by the end of the Eocene, but it is difficult to determine the ancestral type from the fossil evidence at present. The vegetation associated with some of the fossil species suggests that the tribe may have had its origins in rainforest, and became adapted to the typically dry, nutrient-poor conditions of sclerophyllous vegetation during the course of the Tertiary.     

A Middle-Late Eocene inflorescence of Caryophyllaceae from Tasmania, Australia

A new genus and species (Caryophylloflora paleogenica genus and species nova G. J. Jord. & Macphail) are proposed for a fossil inflorescence found in Middle-Late Eocene sediments at Locharbour, northeastern Tasmania, Australia. A parsimony analysis of 75 extant species of the order Caryophyllales and five outgroups placed the fossil within Caryophyllaceae, either subfamily Alsinoideae or Caryophylloideae. The analysis used molecular (rbcL and/or matK), morphological, and anatomical data for the extant species and morphological data for the fossil. Tests on extant species imply that the placement of the fossil should be convincing. The fossil appears to be of a lineage distinct from any extant Australian Caryophyllaceae. In situ pollen are consistent with the form species, Periporopollenites polyoratus. This relatively simple pollen type first appears in Australia and New Zealand in the Late Cretaceous, the oldest known record of the Caryophyllaceae. The last appearance of P. polyoratus in Australia is in the Oligocene, and extant Australian members of the Caryophyllaceae are best interpreted as having evolved from species that dispersed from elsewhere during the Neogene or Quaternary.     

First fossil record of the genus Nageia (Podocarpaceae) in south China and its phytogeographic implications

The first fossil record of the genus Nageia Gaertner from the Tertiary of southern China is reported. Nageia hainanensis sp. nov. is described from the Eocene Changchang Formation of Hainan Island. The extant species of Nageia are widely distributed in southeastern Asia, from northeastern India to southeastern China and southern Japan, and southward through Indochina to the Malay Archipelago and New Guinea. The fossil evidence of Nageia has been discovered from the Lower Cretaceous of the Far East of Russia and Japan. The distribution of both modern and fossil species of Nageia indicates that this genus could have originated in the northeastern part of Asia in the Early Cretaceous and spread to south China at least in the Eocene. Discovery of Nageia fossil record in south China provides important evidence for the geological and phytogeographic history of the genus.     

松科早期球果研究的历史与现状

本文主要对早白垩世到老第三纪渐新世这段时间的松科化石球果的研究作了系统回顾和总结。松科化石球果的研究经历了一个由分散、幼稚到系统、成熟的发展过程,现在将松科化石球果分为三个属：Ｐｉｔｙｏｓｔｒｏｂｕｓ、Ｐｓｅｕｄｏａｒａｕｃａｒｉａ及Ｐｉｎｕｓ。其中Ｐｓｅｕｄｏａｒａｕｃａｒｉａ及Ｐｉｎｕｓ为两个自然属,Ｐｓｅｕｄｏａｒａｕｃａｒｉａ已经绝灭。Ｐｉｔｙｏｓｔｒｏｂｕｓ作为一个器官属,包括那些在松科中分类位置不明的球果。对松科化石球果进行细致的外部形态及内部结构的研究主要目的在于演化关系的探讨上：对于Ｐｉｎｕｓ,主要探讨这个属内各个亚属、组、亚组之间的演化关系;对于Ｐｉｔｙｏｓｔｒｏｂｕｓ和Ｐｓｅｕｄｏａｒａｕｃａｒｉａ,通过绝灭类型的分析,探索松科内各个类群（包括绝灭的）的演化关系进而完成进化树是研究的主要方向,现在这方面已有了Ｐｉｎｕｓ中心说及Ｐｓｅｕｄｏａｒａｕｃａｒｉａ分支说两个假说。     

Australian Lasioglossum + Homalictus form a monophyletic group: resolving the "Australian enigma"

The bee genus Lasioglossum includes > 1,000 species of bees distributed on all continents except Antarctica. Lasioglossum is a major component of the bee fauna in the Holarctic, Ethiopian, and Asian regions and is an important group for investigating the evolution of social behavior in bees. Given its cosmopolitan distribution, the historical biogeography of the genus is of considerable interest. We reconstructed phylogenetic relationships among the subgenera and species within Lasioglossum s.s., using DNA sequence data from a slowly evolving nuclear gene, elongation factor-1 alpha. The entire data set includes > 1,604 aligned nucleotide sites (including three exons plus two introns) for 89 species (17 outgroups plus 72 ingroups). Parsimony and maximum likelihood analyses provide strong evidence that the primarily Indoaustralian subgenera (Homalictus, Chilalictus, Parasphecodes) form a monophyletic group. Bootstrap support for the Australian clade ranged from 73% to 77%, depending on the method of analysis. Monophyly of the Australian Lasioglossum suggests that a single colonization event (by way of Southeast Asia and New Guinea) gave rise to a lineage of > 350 native Indoaustralian bees. We discuss the implications of Australian monophyly for resolving the "Australian enigma"--the similarity in social behavior among the Australian halictine bees relative to that of Holarctic groups.     

Phylogenetics and evolution of the aphid genus Uroleucon based on mitochondrial and nuclear DNA sequences

The genus Uroleucon, and the related genus Macrosiphoniella, represent a large Tertiary radiation of aphids, with a total of about 300 species distributed throughout the world, primarily on host plant species in the family Asteraceae. A molecular phylogenetic study was conducted to identify major clades within Uroleucon and to address the cladistic validity of current subgeneric categories, the evolution of host plant associations, the age of origin, and intercontinental movements in this genus. The seventeen study species included members of the three major subgenera of Uroleucon, species from Europe and North America, one member of Macrosiphoniella, and two outgroups. Data consisted of DNA sequences for three mitochondrial regions and the nuclear gene EF1alpha, for a total of 4287 sites. Nodes supported strongly in both parsimony and maximum likelihood analyses suggest that: (1) Nearctic Uromelan are a monophyletic group branching near the base of the genus and not related to European Uromelan, (2) the New World subgenus Lambersius is possibly monophyletic but is not a tightly related group and is not closely related to other North American species, and (3) Nearctic members of subgenus Uroleucon are a closely related monophyletic group not allied with Nearctic Uromelan or Lambersius. Instead they represent a separate colonization by an Old World ancestor, as they are nested within a strongly supported clade containing European members of both subgenera Uroleucon and Uromelan. Neither of these subgenera is monophyletic. Molecular clock calculations, based on calibrations of mitochondrial divergences from other insects, suggest that Uroleucon + Macrosiphoniella is a relatively recent radiation, probably no more than 5–10 million years old. Although largely confined to Asteraceae, this clade did not radiate in parallel with its host plants. Rather, lateral movement between lineages of Asteraceae must have occurred repeatedly.     

On the relation of Potamomyces armatisporus to the fossil form-type Mediaverrunites and its taxonomical and ecological implications

This study links the spores of the recent ascomycete genus Potamomyces with the fossil form-taxa Mediaverrunites. Spores of the only known representative of Potamomyces, P. armatisporus, were found in recent material from Nepal together with a previously unknown spore type described here for the first time as Potamomyces nepalensis-type. Potamomyces is thus not a monotypic genus. The rarely isolated type species P. armatisporus is known as a lignicolous freshwater ascomycete from tropical rivers. Our findings indicate that the genus also lives in damp conditions in terrestrial habitats, and is recently distributed also in subtropical regions. Based on the fossil findings of Mediaverrunites, the genus Potamomyces evolved at least 25 million yr ago at the onset of younger Tertiary. Potamomyces is an excellent example of the potential of interdisciplinary fungal research, combining insights from fungal evolution, taxonomy, ancient and recent distribution and ecology.     

The fossil record of Limopsis (Bivalvia: Limopsidae) in Antarctica and the southern high latitudes

Abstract: Limopsis is one of the most speciose and widespread bivalve genera in the Southern Ocean at the present day. However, the fossil record of the genus is poorly known from the southern high latitudes. Here, we review the fossil record in this region to help understand the evolutionary origins of the genus. Limopsis infericola sp. nov. and additional specimens of a previously described species are added to the fossil record of Antarctica. The globally distributed limopsid clade had its earliest occurrences in the Early Cretaceous of Europe and New Zealand, then radiated during the Late Cretaceous (Maastrichtian, 70.6–65.5 Ma). Fossil evidence shows that the genus underwent a second, Cenozoic, radiation related to the isolation of Antarctica and the onset of cooling in the southern hemisphere. The genus has persisted in Antarctica for the last 50 myr, adapting to extreme changes in the environmental conditions, including surviving the last glacial maximum in marine refugia.     

A preliminary revision of the supraspecific classification of Kobresia Willd. (Cyperaceae)

Previous supraspecific classifications of the genus Kobresia are evaluated. The evolution of the genus is discussed, and a preliminary revised supraspecific classification based on putative evolution is proposed. Previous classifications were mostly based on inflorescence characters. The spicate inflorescence might have evolved in parallel from a paniculate one, and unisexual spikelet might also be the result of parallel evolution from bisexual spikelets. Therefore, the subgenera or sections Elyna and Hemicarex , which were recognized by previous authors and characterized by the spicate inflorescence (the former with bisexual spikelets and the latter with unisexual ones), may be polyphyletic. In the classification presented here, three subgenera are recognized. A new subgenus Blysmocarex (N. A. Ivanova) S. R. Zhang is proposed. A key to subgenera and sections is included, and types, synonymies and representative species are given under each supraspecific rank.