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1.
Iphisa elegans Gray, 1851 is a ground‐dwelling lizard widespread over Amazonia that displays a broadly conserved external morphology over its range. This wide geographical distribution and conservation of body form contrasts with the expected poor dispersal ability of the species, the tumultuous past of Amazonia, and the previously documented prevalence of cryptic species in widespread terrestrial organisms in this region. Here we investigate this homogeneity by examining hemipenial morphology and conducting phylogenetic analyses of mitochondrial (CYTB) and nuclear (C‐MOS) DNA sequence data from 49 individuals sampled across Amazonia. We detected remarkable variation in hemipenial morphology within this species, with multiple cases of sympatric occurrence of distinct hemipenial morphotypes. Phylogenetic analyses revealed highly divergent lineages corroborating the patterns suggested by the hemipenial morphotypes, including co‐occurrence of different lineages. The degrees of genetic and morphological distinctness, as well as instances of sympatry among mtDNA lineages/morphotypes without nuDNA allele sharing, suggest that I. elegans is a complex of cryptic species. An extensive and integrative taxonomic revision of the I. elegans complex throughout its wide geographical range is needed. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 361–376.  相似文献   

2.
This study is undertaken in order to evaluate specific hypotheses of relationship among extant and extinct sloths (Mammalia, Xenarthra, Tardigrada). Questions of particular interest include the relationship among the three traditional family groupings of extinct ground sloths and the monophyletic or diphyletic origin of the two genera of extant tree sloths. A computer‐based cladistic investigation of the phylogenetic relationships among 33 sloth genera is performed based upon 286 osteological characteristics of the skull, lower jaw, dentition and hyoid arch. Characters are polarized via comparisons with the following successive outgroups, all members of the supraordinal grouping Edentata: the Vermilingua, or anteaters; the Cingulata, or armadillos and glyptodonts; the Palaeanodonta; and the Pholidota, or pangolins. The results of the analysis strongly corroborate the diphyly of living tree sloths, with the three‐toed sloth Bradypus positioned as the sister‐taxon to all other sloths, and the two‐toed sloth Choloepus allied with extinct members of the family Megalonychidae. These results imply that the split between the two extant sloth genera is ancient, dating back perhaps as much as 40 Myr, and that the similarities between the two taxa, including their suspensory locomotor habits, present one of the most dramatic examples of convergent evolution known among mammals. The monophyly of the three traditional ground sloth families Megatheriidae, Megalonychidae and Mylodontidae is confirmed in the present study, and the late Miocene–Pleistocene nothrotheres are shown to form a clade. It is suggested that this latter clade merits recognition as a distinct family‐level grouping, the family Nothrotheriidae. The monophyly of the Megatherioidea, a clade including members of the families Megatheriidae, Megalonychidae and Nothrotheriidae, is also supported. Within Megatherioidea, the families Nothrotheriidae and Megatheriidae form a monophyletic group called the Megatheria. The relationships within the families Megatheriidae and Mylodontidae are fully and consistently resolved, although the hypothesized scheme of relationships among the late Miocene to Pleistocene members of the mylodontid subfamily Mylodontinae differ strongly from any proposed by previous authors. Within the family Megalonychidae, Choloepus is allied to a monophyletic grouping of West Indian sloths, although the relationships within this clade are not fully resolved. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 140 , 255–305.  相似文献   

3.
4.
Species that are dependant on, or adapted to, freshwater environments are found in almost all mammalian orders, and two orders, the Cetacea and the Sirenia, are strictly aquatic and include some freshwater-dependant species. Overall, the aquatic and freshwater-dependant species represent around 70 of the more than 1,200 living or recent genera of mammals, and occur in all continents except Antarctica. They include some of the most endangered species of mammals, and several have gone extinct or become critically endangered in recent decades. One of the main threats is habitat loss or degradation. This chapter provides an overview of the freshwater species within each order of mammals, their evolutionary history, their relations to humans and their conservation status. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

5.
Phylogenetic analysis of the tribe Bovini (Mammalia: Artiodactyla)   总被引:2,自引:0,他引:2  
A matrix of 57 (mainly cranial) characters and 32 taxa of fossil and Recent Bovini (buffaloes, bison and cattle) has been analysed using the parsimony program HENNIG86. Among the best established results are the exclusion of Parabos , polyphyly of Leptobos , monophyly of the Bos sensu lato + buffaloes group (a clade including all Recent Bovini), probable monophyly of the Bubalina and Syncerina, and the close relationship between bison and yak. Some other interesting questions raised include the apparent absence of a close link between Pliocene African bovines (except "Leptobos" syrticus ) and later African buffaloes, and the possible monophyly of Pelorovis oldowayensis+Bos sensu lato .  相似文献   

6.
Some relatively rare carnivore remains from Pikermi are studied. The present specimens include Simocyon primigenius(ROTH and WAGNER, 1854), Promeles palaeatticus(WEITHOFER, 1888), Martes woodwardiPILGRIM, 1931, Felis atticaWAGNER, 1857 and Machairodus giganteus(WAGNER, 1848), as well as some postcranial remains that resemble Enhydriodon? latipesPILGRIM, 1931 and are assigned to Mustelidae gen. et spec. indet. Some of these species were not known until now but from their holotypes as M. woodwardi and E.? latipes. Other species such as F. attica and M. giganteus are better known but from relatively scant material. Since the material of the earlier mentioned species comes from Pikermi, their type locality, it is of especial importance and improves our knowledge for the Pikermi carnivores and their relationships to other species. In some cases where the material comes from ossiferous blocks, the accompanying faunal context is discussed.  相似文献   

7.
During the past three decades knowledge of the earliest mammals has greatly increased through study of specimens of morganucodontids of Late Triassic and Early Jurassic age discovered in Africa, Asia and Europe. Communication of the results of diis research has been and continues to be impaired by disputes over the validity or content of the genera Eozostrodon Parrington and Morganucodon Kiihne. On the basis of the limited data available and in the interest of stability of nomenclature, Eozostrodon parvus is the appropriate name for the morganucodontid represented in the fauna preserved in fissure fillings in Holwell Quarry, England. Its diagnostic dental morphology is not duplicated in the extensive samples of the most abundant morganucodontid known from Wales for which the name Morganucodon watsoni is appropriate. Although generic reference of these species is a moot point, recognition of separate species is warranted and, with other data, points to a diverse assemblage of morganucodontids forming part of the base of a prototherian radiation.  相似文献   

8.
The relationships of the Tritylodontidae (Synapsida)   总被引:1,自引:0,他引:1  
From a detailed anatomical survey of the Tritylodontidae, it is possible to examine the phylogenetic status of this taxon of advanced synapsids. The Tritylodontidae are considered to be the sister-group of the Traversodontidae, specifically the Exaerelodon-Massetognathus assemblage, rather than that of the Mammalia plus Tritheledontidae as recently postulated. Numerous character contradictions reveal considerable parallel evolution among advanced synapsids.  相似文献   

9.
The hyoid apparatus reflects aspects of the form and function of feeding in living and extinct organisms and, despite the availability of information about this structure for Xenarthra, it remains little explored from an evolutionary perspective. Here we compare the morphology of the hyoid apparatus in xenarthrans, describing its general morphology and variation in each major clade and score these variations as phylogenetic characters, which were submitted to ancestral states reconstructions. The general hyoid morphology of Xenarthra consists of a v-bone (basihyal fused with the thyrohyals) and three paired bones (stylohyal, epihyal and ceratohyal), which are unfused in the majority of taxa. The clade-specific morphology observed here, allowed us to obtain additional synapomorphies for all major clades of Xenarthra (Cingulata, Pilosa, Folivora and Vermilingua), for Glyptodontididae, and for Nothrotheriidae. The fusion of hyoid elements are convergentelly achieved among the diphyletic extant tree sloths, some extinct ground sloths and glyptodontids. Despite the heavy influence of adaptive evolution related to feeding habits, the morphology of the hyoid apparatus proved to be a valuable source of phylogenetic information.  相似文献   

10.
The phylogeny of the Rhinocerotoidea (Mammalia, Perissodactyla)   总被引:3,自引:0,他引:3  
A new phylogeny of the Superfamily Rhinocerotoidea is proposed, based upon an analysis of shared derived characters of the skull, teeth and skeleton. Hyrachyus is considered the primitive sister-taxon of the three rhinocerotoid families (Amynodontidae, Hyracodontidae, Rhinocerotidae), and the amynodonts appear to be the sister-group of hyracodonts and rhinocerotids. The relationships of primitive hyracodonts and rhinocerotids are clarified. Menoceras and Pleuroceras (new Subfamily Menoceratinae) are removed from the Diceratheriinae, since they appear to be more closely related to higher rhinoceroses than they are to Diceratherium. Of the three major monophyletic groups of higher rhinocerotids (aceratherines, teleoceratines and rhinocerotines), the last two groups are more closely related to each other than either is to aceratherines. Toxotherium and Schizotheroides are tentatively removed from the Rhinocerotoidea and placed in the Lophiodontidae.  相似文献   

11.
12.
《Geobios》2016,49(6):445-458
The site of Tighennif (= Ternifine) in Northern Algeria, well-known for its Homo mauritanicus (= Homo rhodesiensis?) remains, and probably dating to the late Calabrian, yielded a large assemblage of terrestrial carnivores. Some are identical or probably identical with extant species: Crocuta crocuta and Hyaena hyaena (Hyaenidae), Felis silvestris (Felidae), Mellivora capensis and Poecilictis cf. libyca (Mustelidae), and Vulpes cf. rueppelli (Canidae). In addition, among felids there is an unidentified leopard-like form; a smaller, more common species assigned to Lynx sp. (a genus quite rare in Africa) but which is certainly different from modern forms, an Homotherium that seems to be the last occurrence of the machairodonts in Africa, and a Panthera aff. leo, which is unfortunately too poorly known to be named. Rare bears do not display all derived features of later North African U. bibersoni. Among canids, the Nyctereutes-like jackal Lupulella mohibi is an endemic North African form known until the late middle Pleistocene, and the hunting dog Lycaon magnus is also clearly distinct from the modern species. A single new species is described, Enhydrictis hoffstetteri, a large, otter-like member of the Mustelidae, of a genus that was previously unknown from Africa, and certainly testifies to North–South dispersal across the Mediterranean at some time during the early Pleistocene.  相似文献   

13.
14.
于2013年和2018年在河南信阳新县与浉河共采集到3号鼩鼱成年个体标本,基于齿色特征初步鉴定为劳亚食虫目鼩鼱科麝鼩属(Crocidura)物种。对所采3号标本的Cyt b基因进行PCR扩增和测序,测序结果与GenBank数据库进行比对,并通过构建系统发育关系树进一步明确所采3只标本的分类地位。根据标本形态、头骨特征,结合分子生物学证据,确定该物种为台湾灰麝鼩(C.tanakae),为河南哺乳动物分布新记录种。标本现存于郑州大学生物多样性与生态学研究所(编号分别为IBE20131005、IBE2018100501和IBE2018100502)。  相似文献   

15.
Reexamining the classification proposed by Hurusawa, the phylogeny of Far EasternEuphorbia subgenusEsula was analyzed using thirteen morphological and seventeen phenolic compound data. These data were analyzed independently and in combination using PAUP under the assumptions of Fitch parsimony. Ten species, comprised of three sections and five subsections within Far EasternEuphorbia subg.Esula and one outgroup from subg.Chamaesyce, were used as terminal taxa. The phylogenetic results did not support the sectional classifications within subg.Esula proposed by Hurusawa. SectionDecussatae was nested in the paraphyletic sectEsula in all of the analyses, and the relationship of sectHelioscopiae was equivocal among data sets. The disagreement of data sets over the placement ofEuphorbia ebracteolata is probably due to a hybrid origin of the species and missing phenolic data forE. pallasii. A sister-group relationship of the Korean endemicE. fauriei with the widespreadE. pekinensis was strongly supported by the morphological and phenolic data.  相似文献   

16.
Conohyus indicus is a poorly known tetraconodont suid from the summit of the Lower Siwaliks and the base of the Middle Siwaliks of the Indian Subcontinent. Even though it was first recorded well over a century ago, only 13 specimens have since been described in the literature, consisting of isolated teeth and incomplete mandible and maxilla fragments. We here describe another fragmentary mandible from the Ramnagar Member (uppermost Middle Miocene to basal Late Miocene) of the Siwalik Group, which contains the left canine lacking its tip, the alveolus of P/1 and the left P/2 – P/3 and right P/3 - M/1. The new specimen, albeit incomplete,provides interesting information about the anterior parts of the jaw and throws light on the systematic position of the species as well as the recently described species Conohyus thailandicus from Thailand.  相似文献   

17.
Halosarpheia unicellularis sp. nov. is described from decayed attached wood ofAvicennia marina collected from two mangrove sites in the Red Sea, Egypt. The ascomycete is compared with other marine taxa having ascospores with polar unfurling appendages. It is also compared with other marine genera with oval, round or ellipsoid hyaline, unicellular ascospores, but for which appendages have not been reported. Molecular data confirms the assignment of the fungus toHalosarpheia which forms a clade with the type speciesHalosarpheia fibrosa.  相似文献   

18.
报道了产自贝加尔湖区中中新世Aya洞穴的戈壁古仓鼠(Gobicricetodon)一新种G.filippovisp.nov.。该种以较小的个体和牙齿上的一些原始特征区别于该属其他种类。先前的研究认为Gobicricetodon与近古仓鼠(Plesiodipus)同属于戈壁古仓鼠亚科,然而,它们与欧亚大陆一些置于古仓鼠亚科(Cricetodontinae)内的属在牙齿形态上的高度相似性表明其亲缘关系。为了理清Gobicricetodon和Plesiodipus与Cricetodontinae之间的系统发育关系,也为了阐明这一类群属和属以上级别的分类,使用Mesquite2.72软件作了分支系统学分析。结果获得了3个主要的分支类群,Gobicricetodon,Plesiodipus,Mixocricetodon和Tsaganocricetus同属于其中的一个分支。令人惊奇的是,一些欧洲古仓鼠(Cricetodon)的种,包括其模式种C.sansaniensis也在这一分支内。此外,支序分析还显示上述类群可能起源于欧亚大陆西部的Cricetodon支系。分析的另一项结果指示,Cricetodon属显然是一个多系类群,需要进一步划分为多个属。  相似文献   

19.
The genus Hemitragus includes three species of tahr distributed in distant geographical areas: the Himalayan tahr, H. jemlahicus, occupies the southern flanks of the Himalaya Mountains; the Nilgiri tahr, H. hylocrius, is endemic to southern India; and the Arabian tahr, H. jayakari, is unique to the mountains of south-east Arabia. All previous investigations were based on morphology, and these three species together have never been included in a molecular phylogenetic study. In this study, we constructed a molecular phylogeny of the tribe Caprini sensu lato to determine the taxonomic status of the three species of tahr. Phylogenetic analyses were carried out on a matrix including most extant species currently described in the tribe Caprini sensu lato, and 3165 nucleotide characters, coming from four different markers, i.e., an intron of the nuclear gene coding for the protein kinase C iota, and three mitochondrial genes (subunit II of the cytochrome c oxidase, cytochrome b, and 12S rRNA). The results show that the genus Hemitragus is polyphyletic, as H. jemlahicus is associated with Capra (goats), H. hylocrius is the sister-group of Ovis (sheep), and H. jayakari is allied with Ammotragus lervia (aoudad). In the light of these unexpected results, we revaluate the validity of the morphological characters originally used for defining the genus Hemitragus. At least, we propose a new taxonomy, where the three species of tahr are ranged into three monospecific genera: the genus Hemitragus is restricted to the Himalayan tahr, and two new genera are created: Arabitragus for the Arabian tahr and Nilgiritragus for the Nilgiri tahr.  相似文献   

20.
The Entotympanic of Pangolins and the Phylogeny of the Pholidota (Mammalia)   总被引:3,自引:0,他引:3  
Entotympanics are independent elements present in the auditory bullae of various eutherians. An entotympanic has been reported for extant pangolins of the Order Pholidota, but the actual distribution of this element remains uncertain, in part, because it is a small, loosely attached structure that is often lost in macerated skulls. Consequently, it is unknown whether or not the entotympanic characterizes Pholidota primitively or has evolved within the group. This report addresses the morphology and distribution of the entotympanic among living and extinct pholidotans. An entotympanic occurs in the African pangolins Manis gigantea, M. temminckii, and in one specimen of M. tricuspis. In each, it is a small, nodular bone that occupies a distinct fossa primarily on the basioccipital, the presence of which allows us to assess the occurrence of an entotympanic even in specimens in which the bone has fallen out. Both the entotympanic and the basioccipital facet are lacking in the four remaining extant pangolin species and in the late Eocene pangolin Patriomanis. To assess the significance of this entotympanic distribution, a phylogenetic analysis of extant pangolins plus Patriomanis based on 67 cranial characters was performed. Four different outgroup analyses all resulted in the same single most parsimonious tree, in which the three extant Asian pangolins form a monophyletic clade and the four extant African pangolins fall into a paraphyletic assemblage. Optimization of the entotympanic distribution onto this tree results in two patterns, dependent on the outgroup choice. If Patriomanis is the sole outgroup to the extant pangolins, the entotympanic arises within pangolins as a synapomorphy of Manis gigantea and M. temminckii, convergently acquired in some M. tricuspis. If Xenarthra and Palaeanodonta are employed as outgroups, the entotympanic optimization is ambiguous: the pattern is either as above or the entotympanic is present primitively within Pholidota and lost secondarily in Patriomanis and a clade comprising M. tricuspis, M. tetradactyla, and the Asian forms.  相似文献   

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