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1.
Recent decline of the critically endangered Plains‐wanderer (Pedionomus torquatus), and the application of a simple method for assessing its cause: major changes in grassland structure
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A monitored population of the critically endangered Plains‐wanderer (Pedionomus torquatus) on Victoria's Northern Plains declined by over 90% between 2010 and 2012 following an unusually wet year which led to flooding, excess grass growth and a major change in the structure of native grasslands. The Plains‐wanderer population remained very low on private land during 2013 and 2014 when dry conditions prevailed and domestic stock overgrazed most of its favoured grasslands on red soil. Numbers also remained very low on public reserves despite grassland structure gradually improving there by 2014. In 2015, the population partially recovered in some grasslands protected from overgrazing. Grassland structure is critically important for Plains‐wanderer conservation. The ‘golf ball technique’ proved to be a quick and effective method for measuring grassland structure; it offers a means of accelerating responses to habitat change because it can be easily used by land managers. 相似文献
2.
ADAM M. YATES 《Palaeontology》2011,54(2):373-384
Abstract: A new species of penicillid watering pot shell, Kendrickiana coquinacola sp. nov., is described from the middle Miocene (Balcombian) Bryant Creek Formation of the Murray Basin, South Australia. The new species differs from the extant K. veitchi in its smaller size, much shorter posterior tube, fewer tubules in the anterior watering pot structure, absence of the pedal slit, discontinuous dorsolateral bands of pitted muscle scars on the internal surface of the anterior bulb and habit of cementing itself to the shells in its surrounding environment. The fossil record of Kendrickiana is reviewed. The record from the Dry Creek Sands is discounted, while a record for the extant K. veitchi from the earliest Pleistocene of York Peninsula is added. K. coquinacola indicates the highly derived anatomy of the genus evolved over a 10‐Ma period from the late Oligocene through the early Miocene. 相似文献
3.
Synchronous genetic turnovers across Western Eurasia in Late Pleistocene collared lemmings
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Eleftheria Palkopoulou Mateusz Baca Natalia I. Abramson Mikhail Sablin Paweł Socha Adam Nadachowski Stefan Prost Mietje Germonpré Pavel Kosintsev Nickolay G. Smirnov Sergey Vartanyan Dmitry Ponomarev Johanna Nyström Pavel Nikolskiy Christopher N. Jass Yuriy N. Litvinov Daniela C. Kalthoff Semyon Grigoriev Tatyana Fadeeva Aikaterini Douka Thomas F.G. Higham Erik Ersmark Vladimir Pitulko Elena Pavlova John R. Stewart Piotr Węgleński Anna Stankovic Love Dalén 《Global Change Biology》2016,22(5):1710-1721
Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D. torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next‐generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D. torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50 000 years. The observation of repeated extinctions across such a vast geographical range indicates large‐scale changes in the steppe‐tundra environment in western Eurasia during the last glaciation. All Holocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D. torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D. groenlandicus and D. richardsoni were recovered from a Late Pleistocene site in south‐western Canada. This suggests that D. groenlandicus had a more southern and D. richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex demographical history, which could have had bottom‐up effects in the Late Pleistocene steppe‐tundra ecosystem. 相似文献
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5.
Nick Schultz Marie Keatley Mark Antos Nathan Wong Claire Moxham Brad Farmilo John W. Morgan 《Ecological Management & Restoration》2017,18(2):134-140
A key task for native grassland managers is to assess when biomass reduction is necessary to maintain plant and animal diversity. This requires managers to monitor grassland structure. Parks Victoria and La Trobe University developed a method for rapid assessment of grassland structure using golf balls. Baker‐Gabb et al. (Ecological Management & Restoration, 17, 2016, p235) provide an example of where the method has been used to manage grassland structure to favour an endangered bird, the Plains‐wanderer (Pedionomus torquatus). In this study, we provide further critical analysis of the method using three data sets collected across different parts of Victoria that relate golf ball scores to various habitat attributes. We demonstrate how the golf ball score provides a good surrogate for key aspects of grassland structure. We show that the method does not provide a reliable surrogate for above‐ground biomass or vegetation cover, although we discuss how biomass and cover are not particularly good indicators of grassland structure. We argue that elements of grassland structure may be better correlated with desired conservation outcomes (e.g. plant species diversity or the presence of a particular species) than biomass or cover alone. We discuss examples of how the golf ball method has been used, and how it can be improved. The method will be particularly useful where a link can be demonstrated between golf ball scores and desired conservation outcomes, such as in the case of the Plains‐wanderer. 相似文献
6.
Vladimir S. Lebedev Mikhail Yu. Rusin Elena D. Zemlemerova Vera A. Matrosova Anna A. Bannikova Yulia M. Kovalskaya Alexey S. Tesakov 《Journal of Zoological Systematics and Evolutionary Research》2019,57(3):695-709
Phylogeny of birch mice is estimated using sequences of ten nuclear genes and one mitochondrial gene. Based on the results of tree reconstructions and molecular dating, five major lineages are recognized: “tianschanica,” “concolor,” “caudata,” “betulina,” and “caucasica.” It is established that the three latter lineages constitute a clade and that the long‐tailed birch mouse Sicista caudata is the sister group of the “caucasica” lineage. The “tianschanica” lineage is placed as the sister branch to all other species, however, with insufficient support. The cytochrome b tree is generally concordant with the nuclear topology. The molecular clock results suggest that the radiation among the main lineages occurred in the Late Miocene–Early Pliocene (6.0–4.7 Mya). The correspondence between molecular dating and the fossil record is discussed. Based on nuclear data, a high level of divergence between cryptic species in the “tianschanica” lineage is confirmed. Mitochondrial and nuclear data suggest the existence of a potential cryptic species within Sicista strandi. 相似文献
7.
Three terrestrial Pleistocene coucals (Centropus: Cuculidae) from southern Australia: biogeographical and ecological significance
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Elen Shute Gavin J. Prideaux Trevor H. Worthy 《Zoological Journal of the Linnean Society》2016,177(4):964-1002
Coucals are large, predatory, primarily ground‐dwelling cuckoos of the genus Centropus, with 26 extant species ranging from Africa to Australia. Their evolutionary and biogeographical history are poorly understood and their fossil record almost non‐existent. Only one species (Centropus phasianinus) currently inhabits Australia, but there is now fossil evidence for at least three Pleistocene species. One of these (Centropus colossus) was described from south‐eastern Australia in 1985. Here we describe additional elements of this species from the same site, and remains of two further extinct species from the Thylacoleo Caves of the Nullarbor Plain, south‐central Australia. The skeletal morphology and large size of the three extinct species indicates that they had reduced capacity for flight and were probably primarily ground‐dwelling. The extinct species include the two largest‐known cuckoos, weighing upwards of 1 kg each. They demonstrate that gigantism in this lineage has been more marked in a continental context than on islands, contrary to the impression gained from extant species. The evolutionary relationships of the Australian fossil coucals are uncertain, but our phylogenetic analysis indicates a possible close relationship between one of the Nullarbor species and extant Centropus violaceus from the Bismarck Archipelago. The presence of three coucals in southern Australia markedly extends the geographical range of the genus from tropical Australia into southern temperate regions. This demonstrates the remarkable and consistent ability of coucals to colonize continents despite their very limited flying ability. 相似文献
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9.
Pleistocene Chinese cave hyenas and the recent Eurasian history of the spotted hyena,Crocuta crocuta
Gui‐Lian Sheng Julien Soubrier Jin‐Yi Liu Lars Werdelin Bastien Llamas Vicki A. Thomson Jonathan Tuke Lian‐Juan Wu Xin‐Dong Hou Quan‐Jia Chen Xu‐Long Lai Alan Cooper 《Molecular ecology》2014,23(3):522-533
The living hyena species (spotted, brown, striped and aardwolf) are remnants of a formerly diverse group of more than 80 fossil species, which peaked in diversity in the Late Miocene (about 7–8 Ma). The fossil history indicates an African origin, and morphological and ancient DNA data have confirmed that living spotted hyenas (Crocuta crocuta) of Africa were closely related to extinct Late Pleistocene cave hyenas from Europe and Asia. The current model used to explain the origins of Eurasian cave hyena populations invokes multiple migrations out of Africa between 3.5–0.35 Ma. We used mitochondrial DNA sequences from radiocarbon‐dated Chinese Pleistocene hyena specimens to examine the origin of Asian populations, and temporally calibrate the evolutionary history of spotted hyenas. Our results support a far more recent evolutionary timescale (430–163 kya) and suggest that extinct and living spotted hyena populations originated from a widespread Eurasian population in the Late Pleistocene, which was only subsequently restricted to Africa. We developed statistical tests of the contrasting population models and their fit to the fossil record. Coalescent simulations and Bayes Factor analysis support the new radiocarbon‐calibrated timescale and Eurasian origins model. The new Eurasian biogeographic scenario proposed for the hyena emphasizes the role of the vast steppe grasslands of Eurasia in contrast to models only involving Africa. The new methodology for combining genetic and geological data to test contrasting models of population history will be useful for a wide range of taxa where ancient and historic genetic data are available. 相似文献
10.
TREVOR H. WORTHY 《Zoological Journal of the Linnean Society》2011,163(1):277-314
Tertiary cormorant fossils (Aves: Phalacrocoracidae) from Late Oligocene deposits in Australia are described. They derive from the Late Oligocene – Early Miocene (26–24 Mya) Etadunna and Namba Formations in the Lake Eyre and Lake Frome Basins, South Australia, respectively. A new genus, Nambashag gen. nov. , with two new species ( Nambashag billerooensis sp. nov. , 30 specimens; Nambashag microglaucus sp. nov. , 14 specimens), has been established. Phylogenetic analyses based on 113 morphological and two integumentary characters indicated that Nambashag is the sister taxon to the Early Miocene Nectornis miocaenus of Europe and all extant phalacrocoracids. As Nambashag, Nectornis, and extant phalacrocoracids constitute a strongly supported clade sister to Anhinga species, the fossil taxa have been referred to Phalacrocoracidae. Sulids and Fregata were successive sister taxa to the Phalacrocoracoidea, i.e. phalacrocoracids + Anhinga. As phalacrocoracids lived in both Europe and Australia during the Late Oligocene and no older phalacrocoracid taxa are known, the biogeographical origin of cormorants remains unanswered. The phylogenetic relationships of extant taxa were not wholly resolved, but contrary to previous morphological analyses, considerable concordance was found with relationships recovered by recent molecular analyses. Microcarbo is sister to all other extant phalacrocoracids, and all Leucocarbo species form a well‐supported clade. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 277–314. 相似文献
11.
AARON D. PAN BONNIE F. JACOBS PATRICK S. HERENDEEN 《Botanical journal of the Linnean Society. Linnean Society of London》2010,163(1):44-54
New species of caesalpinioid legumes, Cynometra sensu lato and Afzelia, are described from the Late Oligocene (27.23 Ma) Guang River flora in north‐western Ethiopia. Both taxa show leaf characteristics that are shared with extant species in the Guineo‐Congolian, Sudanian and/or Zambezian regions of Africa today. The presence of these two species in Ethiopia during the Palaeogene provides further evidence of the importance of the legume tribe Detarieae in northern and north‐eastern Africa throughout much of the Cenozoic, even although the clade is poorly represented in these regions today. The fossil record documents a significant palaeogeographical and evolutionary history of Detarieae in Africa, especially compared with that of Europe and Anatolia. Based on this evidence, it is unlikely that significant diversification of extant African Detarieae took place on the Eurasian landmass. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 44–54. 相似文献
12.
Aim Gondwanan lineages are a prominent component of the Australian terrestrial biota. However, most squamate (lizard and snake) lineages in Australia appear to be derived from relatively recent dispersal from Asia (< 30 Ma) and in situ diversification, subsequent to the isolation of Australia from other Gondwanan landmasses. We test the hypothesis that the Australian radiation of diplodactyloid geckos (families Carphodactylidae, Diplodactylidae and Pygopodidae), in contrast to other endemic squamate groups, has a Gondwanan origin and comprises multiple lineages that originated before the separation of Australia from Antarctica. Location Australasia. Methods Bayesian (beast ) and penalized likelihood rate smoothing (PLRS) (r 8s ) molecular dating methods and two long nuclear DNA sequences (RAG‐1 and c‐mos) were used to estimate a timeframe for divergence events among 18 genera and 30 species of Australian diplodactyloids. Results At least five lineages of Australian diplodactyloid geckos are estimated to have originated > 34 Ma (pre‐Oligocene) and basal splits among the Australian diplodactyloids occurred c. 70 Ma. However, most extant generic and intergeneric diversity within diplodactyloid lineages appears to post‐date the late Oligocene (< 30 Ma). Main conclusions Basal divergences within the diplodactyloids significantly pre‐date the final break‐up of East Gondwana, indicating that the group is one of the most ancient extant endemic vertebrate radiations east of Wallace’s Line. At least five Australian lineages of diplodactyloid gecko are each as old or older than other well‐dated Australian squamate radiations (e.g. elapid snakes and agamids). The limbless Pygopodidae (morphologically the most aberrant living geckos) appears to have radiated before Australia was occupied by potential ecological analogues. However, in spite of the great age of the diplodactyloid radiation, most extant diversity appears to be of relatively recent origin, a pattern that is shared with other Australian squamate lineages. 相似文献
13.
Aim Australian scincid lizards represent three distinct groups within the cosmopolitan clade Lygosominae, the Egernia, Eugongylus and Sphenomorphus groups. This paper presents a time‐calibrated phylogeny for Lygosominae that provides the necessary temporal framework for assessing the contributions of immigration from Asia and of Gondwanan inheritance in the derivation of the Australian scincid fauna. Location Australasia, Asia, Africa. Methods Phylogenetic relationships and divergence times were inferred from novel BDNF, c‐mos and PTPN12 sequences (2408 aligned sites). Results Lygosomine monophyly is well supported, and there is strong support for monophyly of the Egernia, Eugongylus and Sphenomorphus groups. A sister‐group relationship of Tribolonotus (distributed in Melanesia and the Papuan Region) and the Egernia group is strongly supported in both Bayesian and maximum likelihood analyses. Australian representatives of the Sphenomorphus group compose a significantly supported clade estimated to have originated c. 25 Ma. An age of c. 18 Ma is inferred for a strongly supported clade comprising Australian representatives of the Egernia group; this clade diverged from Corucia zebrata (confined to the Solomon Islands) c. 25 Ma and from Tribolonotus c. 54 Ma. A well‐supported clade including all Australian Eugongylus group taxa sampled is estimated to have arisen c. 20 Ma. Main conclusions The Australian Sphenomorphus group is nested within the more inclusive Sphenomorphus group (distributed primarily in Asia and Australasia), suggesting comparatively recent descent from a colonizing Asian ancestor; the divergence times inferred here indicate that colonization occurred during the mid Cenozoic, subsequent to the rifting of Australia from Antarctica. An Oligocene origin of the extant Eugongylus group fauna of Australasia (the basal members of which are distributed in the Southwest Pacific) indicates that Eugongylus group lygosomines also dispersed to Australia relatively recently. The Egernia group diverged from Tribolonotus in the Early Eocene; however, extant Egernia group lygosomines originated only during the Late Oligocene, implying extensive pruning of stem taxa (i.e. extinction). As a result, inferences of the timing of dispersal into Australia are associated with substantial uncertainty, although independent palaeontological evidence suggests that the Egernia group entered Australia prior to the Oligocene, immediately after (or perhaps before) the separation of Australia and Antarctica. 相似文献
14.
Aim To test whether environmental diversification played a role in the diversification of the New Caledonian Hydropsychinae caddisflies. Location New Caledonia, south‐west Pacific. Methods The phylogeny of the New Caledonian Hydropsychinae caddisflies was hypothesized using parsimony and Bayesian methods on molecular characters. The Bayesian analysis was the basis for a comparative analysis of the correlation between phylogeny and three environmental factors: geological substrate (ultrabasic, non‐ultrabasic), elevation and precipitation. Phylogenetic divergence times were estimated using a relaxed clock method, and environmental factors were mapped onto a lineage‐through‐time plot to investigate the timing of environmental diversification in relation to species radiation. The correlation between rainfall and elevation was tested using independent contrasts, and the gamma statistic was calculated to infer the diversification pattern of the group. Results The diversification of extant Orthopsyche–Caledopsyche species began in the Middle–Late Oligocene, when much of the island of New Caledonia was covered by ultrabasic substrate and mountain forming was prevalent. Most lineages originated in the Middle–Late Miocene, a period associated with long‐term climate oscillation. Optimization of environmental factors on the phylogeny demonstrated that the New Caledonian Hydropsychinae group adapted to ultrabasic substrate early in its evolutionary history. The clade living mostly on ultrabasic substrate was far more species‐rich than the clade living mostly on non‐ultrabasic substrate. Elevation and rainfall were significantly correlated with each other. The lineage‐through‐time plot revealed that the main environmental diversification preceded species diversification. A constant speciation through time was rejected, and the negative gamma indicates that most of the diversification occurred early in the history of the clade. According to the inferred phylogeny, the genus Orthopsyche McFarlane is a synonym under Caledopsyche Kimmins, and Abacaria caledona Oláh & Barnard should also be included in Caledopsyche. Main conclusions The age of the radiation does not support a vicariance origin of New Caledonian Hydropsychinae caddisflies. Environmental diversification pre‐dates lineage diversification, and thus environmental heterogeneity potentially played a role in the diversification of the group, by providing a variety of fragmented habitats to disperse into, promoting speciation. The negative gamma indicates that the speciation rate slowed as niches started to fill. 相似文献
15.
Small mammal (rodents and lagomorphs) European biogeography from the Late Oligocene to the mid Pliocene 总被引:2,自引:0,他引:2
Olivier Maridet Gilles Escarguel Loïc Costeur Pierre Mein Marguerite Hugueney Serge Legendre 《Global Ecology and Biogeography》2007,16(4):529-544
Aim To analyse the fossil species assemblages of rodents and lagomorphs from the European Neogene in order to assess what factors control small mammal biogeography at a deep‐time evolutionary time‐scale. Location Western Europe: 626 fossil‐bearing localities located within 31 regions and distributed among 18 successive biochronological units ranging from c. 27 Ma (million years ago; Late Oligocene) to c. 3 Ma (mid Pliocene). Methods Taxonomically homogenized pooled regional assemblages are compared using the Raup and Crick index of faunal similarity; then, the inferred similarity matrices are visualized as neighbour‐joining trees and by projecting the statistically significant interregional similarities and dissimilarities onto palaeogeographical maps. The inferred biogeographical patterns are analysed and discussed in the light of known palaeogeographical and palaeoclimatic events. Results Successive time intervals with distinct biogeographical contexts are identified. Prior to c. 18 Ma (Late Oligocene and Early Miocene), a relative faunal homogeneity (high interregional connectivity) is observed all over Europe, a time when major geographical barriers and a weak climatic gradient are known. Then, from the beginning of the Middle Miocene onwards, the biogeography is marked by a significant decrease in interregional faunal affinities which matches a drastic global climatic degradation and leads, in the Late Miocene (c. 11 Ma), to a marked latitudinal pattern of small mammal distribution. In spite of a short rehomogenization around the Miocene/Pliocene boundary (6–4 Ma), the biogeography of small mammals in the mid Pliocene (c. 3 Ma) finally closely reflects the extant situation. Main conclusions The resulting biogeographical evolutionary scheme indicates that the extant endemic situation has deep historical roots corresponding to global tectonic and climatic events acting as primary drivers of long‐term changes. The correlation of biogeographical events with climatic changes emphasizes the prevalent role of the climate over geography in generating heterogeneous biogeographical patterns at the continental scale. 相似文献
16.
Alessio Capobianco Matt Friedman 《Biological reviews of the Cambridge Philosophical Society》2019,94(2):662-699
Widespread fish clades that occur mainly or exclusively in fresh water represent a key target of biogeographical investigation due to limited potential for crossing marine barriers. Timescales for the origin and diversification of these groups are crucial tests of vicariant scenarios in which continental break‐ups shaped modern geographic distributions. Evolutionary chronologies are commonly estimated through node‐based palaeontological calibration of molecular phylogenies, but this approach ignores most of the temporal information encoded in the known fossil record of a given taxon. Here, we review the fossil record of freshwater fish clades with a distribution encompassing disjunct landmasses in the southern hemisphere. Palaeontologically derived temporal and geographic data were used to infer the plausible biogeographic processes that shaped the distribution of these clades. For seven extant clades with a relatively well‐known fossil record, we used the stratigraphic distribution of their fossils to estimate confidence intervals on their times of origin. To do this, we employed a Bayesian framework that considers non‐uniform preservation potential of freshwater fish fossils through time, as well as uncertainty in the absolute age of fossil horizons. We provide the following estimates for the origin times of these clades: Lepidosireniformes [125–95 million years ago (Ma)]; total‐group Osteoglossomorpha (207–167 Ma); Characiformes (120–95 Ma; a younger estimate of 97–75 Ma when controversial Cenomanian fossils are excluded); Galaxiidae (235–21 Ma); Cyprinodontiformes (80–67 Ma); Channidae (79–43 Ma); Percichthyidae (127–69 Ma). These dates are mostly congruent with published molecular timetree estimates, despite the use of semi‐independent data. Our reassessment of the biogeographic history of southern hemisphere freshwater fishes shows that long‐distance dispersals and regional extinctions can confound and erode pre‐existing vicariance‐driven patterns. It is probable that disjunct distributions in many extant groups result from complex biogeographic processes that took place during the Late Cretaceous and Cenozoic. Although long‐distance dispersals likely shaped the distributions of several freshwater fish clades, their exact mechanisms and their impact on broader macroevolutionary and ecological dynamics are still unclear and require further investigation. 相似文献
17.
Tortoise (Reptilia,Testudinidae) radiations in Southern Africa from the Eocene to the present
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Margaretha D. Hofmeyr Melita Vamberger William Branch Alfred Schleicher Savel R. Daniels 《Zoologica scripta》2017,46(4):389-400
Africa, inclusive of the West Indian Ocean islands, harbours 11 of the world's 16 extant testudinid genera. Fossil records indicate that testudinids originated in Asia and dispersed first to North America and Europe (Early Eocene) and later to Africa (Late Eocene). We used mitochondrial (1870 bp) and nuclear (1416 bp) DNA sequence data to assess whether molecular data support the late cladogenesis of Southern African testudinid lineages. Our results revealed strong support for the monophyly of a clade consisting of Kinixys, the two Malagasy genera and four Southern African genera (Psammobates, Stigmochelys, Homopus and Chersina). Kinixys diverged from this clade in the Late Palaeocene, suggesting that testudinids occupied Africa at an earlier date than indicated by fossil records. The Southern African tortoises consist of three, strongly supported clades: Psammobates + Stigmochelys; the five‐toed Homopus + Chersina; and the four‐toed Homopus. Due to the paraphyly of Homopus, we propose the taxonomic resurrection of Chersobius for the five‐toed Homopus species (boulengeri, signatus and solus). Cladogenesis at the genus level occurred mainly in the Eocene, with Chersina and Chersobius diverging in the Oligocene. The latter divergence coincided with species‐level radiations within Homopus (areolatus and femoralis) and Psammobates (oculifer, geometricus and tentorius). Our phylogeny could not resolve relationships within Psammobates, indicating rapid speciation between the Late Oligocene and Early Miocene. The Chersobius species were the last to diverge in the Early to Mid‐Miocene. By the Mid‐Miocene, P. tentorius started to differentiate into four lineages instead of the three recognized subspecies: P. t. tentorius, P. t. trimeni and two P. t. verroxii subclades occurring north and south of the Orange River, respectively. Terminal radiations in several taxa suggest the existence of cryptic species and a more diverse tortoise fauna than currently recognized. Factors contributing to this diversity may include the early origin of African testudinids and climatic fluctuations over a heterogeneous landscape. 相似文献
18.
The Miocene tortoise Testudo catalaunica Bataller, 1926, and a revised phylogeny of extinct species of genus Testudo (Testudines: Testudinidae)
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Àngel H. Luján Massimo Delfino Josep M. Robles David M. Alba 《Zoological Journal of the Linnean Society》2016,178(2):312-342
We provide a taxonomic review of the extinct testudinid Testudo catalaunica, based on published and unpublished material from several Miocene (late Aragonian and early Vallesian) sites of the Vallès‐Penedès Basin (north‐east Iberian Peninsula). We show that Testudo catalaunica irregularis is a junior subjective synonym of T. catalaunica, and further provide an emended diagnosis of the latter based on newly reported material. Contrary to some recent suggestions, this emended diagnosis discounts an alternative attribution of T. catalaunica to Paleotestudo. The latter is merely recognized as a subgenus of Testudo, based on a cladistic analysis that assessed the phylogenetic position of all extant and most extinct species of Testudo currently recognized as valid (including T. catalaunica). Our phylogenetic analysis (which recovers the molecular phylogeny of extant Testudo s.l.) supports a taxonomic scheme in which the three extant subgenera of Testudo are represented in the fossil record. Testudo s.s. is retrieved as the sister taxon of Testudo (Agrionemys) + [Testudo (Paleotestudo) + Testudo (Chersine)]. The extinct Testudo (Paleotestudo) is therefore the sister taxon of the Testudo (Chersine) clade. The latter subgenus reveals as the most diverse clade of Testudo s.l. in the fossil record, with T. catalaunica + Testudo steinheimensis constituting a subclade distinct from that including Testudo hermanni. 相似文献
19.
Geographical structure,narrow species ranges,and Cenozoic diversification in a pantropical clade of epiphyllous leafy liverworts
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Julia Bechteler Alfons Schäfer‐Verwimp Gaik Ee Lee Kathrin Feldberg Oscar Alejandro Pérez‐Escobar Tamás Pócs Denilson F. Peralta Matthew A. M. Renner Jochen Heinrichs 《Ecology and evolution》2017,7(2):638-653
The evolutionary history and classification of epiphyllous cryptogams are still poorly known. Leptolejeunea is a largely epiphyllous pantropical liverwort genus with about 25 species characterized by deeply bilobed underleaves, elliptic to narrowly obovate leaf lobes, the presence of ocelli, and vegetative reproduction by cladia. Sequences of three chloroplast regions (rbcL, trnL‐F, psbA) and the nuclear ribosomal ITS region were obtained for 66 accessions of Leptolejeunea and six outgroup species to explore the phylogeny, divergence times, and ancestral areas of this genus. The phylogeny was estimated using maximum‐likelihood and Bayesian inference approaches, and divergence times were estimated with a Bayesian relaxed clock method. Leptolejeunea likely originated in Asia or the Neotropics within a time interval from the Early Eocene to the Late Cretaceous (67.9 Ma, 95% highest posterior density [HPD]: 47.9–93.7). Diversification of the crown group initiated in the Eocene or early Oligocene (38.4 Ma, 95% HPD: 27.2–52.6). Most species clades were established in the Miocene. Leptolejeunea epiphylla and L. schiffneri originated in Asia and colonized African islands during the Plio‐Pleistocene. Accessions of supposedly pantropical species are placed in different main clades. Several monophyletic morphospecies exhibit considerable sequence variation related to a geographical pattern. The clear geographic structure of the Leptolejeunea crown group points to evolutionary processes including rare long‐distance dispersal and subsequent speciation. Leptolejeunea may have benefitted from the large‐scale distribution of humid tropical angiosperm forests in the Eocene. 相似文献
20.
Anagaw Atickem Nils Chr. Stenseth Marine Drouilly Steffen Bock Christian Roos Dietmar Zinner 《Zoologica scripta》2018,47(1):1-8
Recently, molecular analyses revealed that African and Eurasian golden jackals are distinct species. This finding suggests re‐investigation of the phylogenetic relationships and taxonomy of other African members of the Canidae. Here, we provide a study on the phylogenetic relationship between populations of African jackals Lupulella mesomelas and L. adusta inferred from 962 bp of the mitochondrial cytochrome b (cytb) gene. As expected from its disjunct distribution, with one population in eastern Africa and the other one in southern Africa, we found two mitochondrial lineages within L. mesomelas, which diverged about 2.5 million years ago (Ma). In contrast, in L. adusta with its more continuous distribution in sub‐Saharan Africa, we found only a shallower genetic diversification, with the exception of the West African population, which diverged around 1.4 Ma from the Central and East African populations. Both divergence ages are older than, for example the 1.1–0.9 million years between the grey wolf Canis lupus and the African golden wolf C. lupaster. One taxonomic implication of our findings might be that the two L. mesomelas populations warrant species status. However, genome‐wide data with adequate geographical sampling are needed to substantiate our results. 相似文献