中国肥螈属(两栖纲:蝾螈科)一新种——弓斑肥螈Pachytriton archospotus sp. nov.

本文记述两栖纲蝾螈目蝾螈科一新种,新种具肥螈属(Pachytriton)系列特征,与肥螈属已知2种比较有明显区别.如1)本新种与黑斑肥螈(Pachytriton brevipes)相似,体表具黑色小圆斑,但新种具额鳞弓、上鳃骨直而与后者不同;无斑肥螈(Pachytriti on labiatus)(地模标本)虽具额鳞弓,但上鳃骨明显弯曲,体表无黑色小圆斑;2) 新种吻短,吻长小于眼间距,黑斑肥螈吻长大于眼间距,无斑肥螈吻长大于或等于眼间距, 它们的头型明显不同,虽然三者头长均大于头宽,但头长、吻长、眼间距差异显著;3)繁 殖期新种雄体肛区不明显肿胀,肛裂周边中、后部生殖乳突长,而且多,十分醒目;黑斑肥 螈和无斑肥螈繁殖期肛区明显肿胀膨大,生殖乳突较短、且稀.经统计分析三种肥螈的头体长、头长、头宽、吻长和眼间距存在显著差异     

Morphology and function of the tongue and hyoid apparatus in Varanus (Varanidae, Lacertilia)

The morphology and function of the tongue and hyoid apparatus in Varanus were examined by anatomical and experimental techniques. Morphological features unique to Varanus include a highly protrusible tongue that has lost a roughened dorsal surface, an exceptionally strong and mobile hyobranchial apparatus, a well-defined joint between the ceratohyal and anterior process, and a series of distinct muscles inserting at the anterior hyobranchial region. Varanus is also unusual among lizards in a number of feeding behaviors; it ingests prey entirely by inertial feeding, as the tongue does not participate in food transport. Further specializations include an increased reliance on hyobranchial movements in drinking and pharyngeal packing and compression. The long, narrow tongue is most likely related to the mechanics of tongue protrusion; the increased amount, strength, and complexity of hyobranchial movement is related to the fact that the hyobranchium in Varanus replaces the tongue in many functions. Previous hypotheses for the origin of these adaptations are discussed, and the difficulties of attributing these specializations to any specific scenario of adaptation or constraint are emphasized.     

A comparative study of the hyobranchial apparatus in Hynobiidae (Amphibia: Urodela)

The morphology of the adult hyobranchial apparatus has played an important role in understanding the systematics and evolution of urodeles, but the hyobranchial apparatus of hynobiid salamanders has received little attention so far. In this study, the hyobranchial apparatus of eight hynobiid salamanders (Hynobius leechii, Onychodactylus zhangyapingi, Ranodon sibiricus, Batrachuperus pinchonii, Salamandrella keyserlingii, Liua shihi, Pachyhynobius shangchengensis and Pseudohynobius flavomaculatus) is described and compared based on the clearing and double-staining method. The basic elements of the hyobranchial apparatus of the eight species are similar, including one basibranchial, cornua, one pair of radial loops, one pair of ceratohyals, one pair of hypobranchials II, one pair of ceratobranchials II, one urohyal (absent in O. zhangyapingi), one pair of the complex of hypobranchial I and ceratobranchial I (separated in certain species). Although the hyobranchial apparatus is similar among hynobiid salamanders and shows a unique morphological pattern, there are also certain species-specific distinctions that may be used for specific or generic diagnosis. The results of an ancestral state reconstruction of five traits showed that the ossified basibranchial, the presence of a separated hypobranchial I and ceratobranchial I, the absence of a urohyal, the ossified hypobranchial I and the partially ossified ceratohyal are derived traits. The state shown by the traits of each species is consistent with the phylogenetic position of each species. Compared with other Urodela, the hyobranchial apparatus of this group shows certain distinctive features that may represent the diagnostic characters of the family Hynobiidae. The partially ossified ceratohyal is correlated with the habitat and represents an ecological adaptation.     

雌性瑶山肥螈泄殖腔显微结构研究

本文对雌性瑶山肥螈的泄殖腔进行了比较解剖学研究,发现雌性瑶山肥螈泄殖腔具有和其它有尾两栖类相似的皮肤形态。虽然不同部位皮肤组织的厚度存在一定差异,但都具有表皮和真皮等相同的基本结构。雌性瑶山肥螈的泄殖腔还具有和精子储藏相关的特殊腺体结构,即储精管腺和腹腺等腺体,以及与这些腺体结构相关的泄殖腔管。这表明该物种雌性个体的泄殖腔具备了精子储藏功能的形态结构,为其进行多次交配,分批产卵提供了基础。     

Unmasking Pachytriton labiatus (Amphibia: Urodela: Salamandridae), with description of a new species of Pachytriton from Guangxi, China

Examination of the lectotype and paralectotypes of Pachytriton labiatus ( Unterstein, 1930 ) from southern China revealed that the specimens do not represent a member of Pachytriton, but are identical with a newt of another genus, Paramesotriton ermizhaoi Wu et al., 2009 also described from southern China. We suggest that Pac. labiatus should be transferred to Paramesotriton as a senior synonym of Par. ermizhaoi. We compared the morphology of the northeastern and southwestern groups of newts previously called Pac. "labiatus" with special reference to age and sexual variations. As a result, we confirmed that the two groups are differentiated sufficiently to be treated as different species. In this report, we revive the name Pac. granulosus Chang, 1933 to refer to the northeastern group of Pac. "labiatus," and at the same time, describe a new species representing the southwestern group.     

DO LARVAL TRAITS RE‐EVOLVE? EVIDENCE FROM THE EMBRYOGENESIS OF A DIRECT‐DEVELOPING SALAMANDER,PLETHODON CINEREUS

Recent molecular phylogenies suggest the surprising reacquisition of posthatching metamorphosis within an otherwise direct-developing clade of lungless salamanders (family Plethodontidae). Metamorphosis was long regarded as plesiomorphic for plethodontids, yet the genus Desmognathus, which primarily includes metamorphosing species, is now nested within a much larger clade of direct-developing species. The extent to which the putative reacquisition of metamorphosis in Desmognathus represents a true evolutionary reversal is contingent upon the extent to which both larva-specific features and metamorphosis were actually lost during the evolution of direct development. In this study we analyze development of the hyobranchial skeleton, which is dramatically remodeled during salamander metamorphosis, in the direct-developing red-backed salamander, Plethodon cinereus. We find dramatic remodeling of the hyobranchial skeleton during embryogenesis in P. cinereus and the transient appearance of larva-specific cartilages. Hyobranchial development in this direct-developing plethodontid is highly similar to that in metamorphosing plethodontids (e.g., Desmognathus). The proposed reacquisition of hyobranchial metamorphosis within Desmognathus does not represent the "re-evolution" of a lost phenotype, but instead the elaboration of an existing developmental sequence.     

Metamorphosis of cranial design in tiger salamanders (Ambystoma tigrinum): A morphometric analysis of ontogenetic change

While ontogenetic analyses of skull development have contributed to our understanding of phylogenetic patterns in vertebrates, there are few studies of taxa that undergo a relatively discrete and rapid change in morphology during development (metamorphosis). Morphological changes occurring in the head at metamorphosis in tiger salamanders (Ambystoma tigrinum) were quantified by a morphometric analysis of cranial osteology and myology to document patterns of change during metamorphosis. We employed a cross-sectional analysis using a sample of larvae just prior to metamorphosis and a sample of transformed individuals just after metamorphosis, as well as larvae undergoing metamorphosis. There were no differences in external size of the head among the larval and transformed samples. The hyobranchial apparatus showed many dramatic changes at metamorphosis, including shortening of ceratobranchial 1 and the basibranchial. The subarcualis rectus muscle increased greatly in length at metamorphosis, as did hypobranchial length and internasal distance. A truss analysis of dorsal skull shape showed that at metamorphosis the snout becomes wider, the maxillary and squamosal triangles rotate posteromedially, and the neurocranium shortens (while maintaining its width), resulting in an overall decrease in skull length at metamorphosis. These morphometric differences are interpreted in light of recent data on the functional morphology of feeding in salamanders. Morphological reorganization of the hyobranchial apparatus and shape changes in the skull are related to the acquisition of a novel terrestrial feeding mode (tongue projection) at metamorphosis. Metamorphic changes (both internal and external) that can be used to judge metamorphic condition are discussed.     

Experimental morphology of the feeding mechanism in salamanders

The subarcualis rectus I muscle (SAR) in the feeding mechanism of four tiger salamanders (Ambystoma tigrinum) was removed early in ontogeny and these individuals were allowed to complete metamorphosis. This procedure resulted in postmetamorphic tiger salamanders which differed from control individuals in the size (and thus force generating capacity) of the SAR muscle. The experimental manipulation of muscle ontogeny allowed a test of previous hypotheses of SAR function in postmetamorphic individuals. Multivariate analysis of variance for kinematic variables measured from high-speed video records of feeding revealed that experimentally modified tiger salamanders did not protract the hyobranchial apparatus or project the tongue from the mouth during feeding. Removal of the SAR muscle resulted in significantly reduced hyobranchial elevation in the buccal cavity and reduced maximum tongue projection distance.     

The hyal and ventral branchial muscles in caecilian and salamander larvae: Homologies and evolution

Amphibians (Lissamphibia) are characterized by a bi‐phasic life‐cycle that comprises an aquatic larval stage and metamorphosis to the adult. The ancestral aquatic feeding behavior of amphibian larvae is suction feeding. The negative pressure that is needed for ingestion of prey is created by depression of the hyobranchial apparatus as a result of hyobranchial muscle action. Understanding the homologies of hyobranchial muscles in amphibian larvae is a crucial step in understanding the evolution of this important character complex. However, the literature mostly focuses on the adult musculature and terms used for hyal and ventral branchial muscles in different amphibians often do not reflect homologies across lissamphibian orders. Here we describe the hyal and ventral branchial musculature in larvae of caecilians (Gymnophiona) and salamanders (Caudata), including juveniles of two permanently aquatic salamander species. Based on previous alternative terminology schemes, we propose a terminology for the hyal and ventral branchial muscles that reflects the homologies of muscles and that is suited for studies on hyobranchial muscle evolution in amphibians. We present a discussion of the hyal and ventral branchial muscles in larvae of the most recent common ancestor of amphibians (i.e. the ground plan of Lissamphibia). Based on our terminology, the hyal and ventral branchial musculature of caecilians and salamanders comprises the following muscles: m. depressor mandibulae, m. depressor mandibulae posterior, m. hyomandibularis, m. branchiohyoideus externus, m. interhyoideus, m. interhyoideus posterior, m. subarcualis rectus I, m. subarcualis obliquus II, m. subarcualis obliquus III, m. subarcualis rectus II‐IV, and m. transversus ventralis IV. Except for the m. branchiohyoideus externus, all muscles considered herein can be assigned to the ground plan of the Lissamphibia with certainty. The m. branchiohyoideus externus is either apomorphic for the Batrachia (frogs + salamanders) or salamander larvae depending on whether or not a homologous muscle is present in frog tadpoles. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.     

A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia

The highly specialized feeding apparatus of modern birds is characterized in part by paraglossalia, triangular bones or cartilages in the tongue that constitute part of the rarely fossilized hyobranchial apparatus. Here, we report on a new, juvenile specimen of the ankylosaurid dinosaur Pinacosaurus grangeri Gilmore, 1933 that provides the first evidence of paraglossalia outside of crown group Aves. The specimen is remarkable in preserving a well‐ossified hyobranchial apparatus, including paired paraglossalia, first and second ceratobranchials, epibranchials, and evidence of a median cartilaginous basihyal. Reassessment of Edmontonia, another ankylosaur, also reveals evidence of bony paraglossalia. Ankylosaur paraglossalia closely resemble those of birds, but are relatively larger and bear prominent muscle scars, supporting the hypothesis that ankylosaurs had fleshy, muscular tongues. The other hyobranchial elements, surprisingly, resemble those of terrestrially feeding salamanders. Ankylosaurs had reduced, slowly replacing teeth, as evidenced from dental histology, suggesting that they relied greatly on their tongues and hyobranchia for feeding. Some curved, rod‐like elements of other dinosaur hyobranchia are reinterpreted as second ceratobranchials, rather than first ceratobranchials as commonly construed. Ankylosaurs provide rare fossil evidence of deep homology in vertebrate branchial arches and expose severe biases against the preservation and collection of the hyobranchial apparatus. In light of these biases, we hypothesize that paraglossalia were present in the common ancestor of Dinosauria, indicating that some structures of the highly derived avian feeding apparatus were in place by the Triassic Period. © 2015 The Linnean Society of London     

Tongue evolution in the lungless salamanders,family plethodontidae. II. Function and evolutionary diversity

A recently presented model of tongue projection dynamics is used to generate a series of predictions concerning morphologies to be expected under selection for increased distance of projection, increased speed of projection, and increased directional versatility. A general understanding of biomechanical events and the model are used as points of departure for making specific predictions concerning details of structure in skeletal, muscular and connective tissue components of the tongue and associated structures. Comparative methods are used to examine these predictions in the genera of plethodontid salamanders. These salamanders are known to project their tongues to different degrees, and this knowledge is used to test the hypotheses concerning morphological specialization. Three distinct groups of plethodontid salamanders have evolved specializations for long distance projection, and these genera differ from one another in important ways in respect to specific character complexes. For example, the tropical genera and Hydromantes use CBII as the major force transmission element in the skeleton, while Eurycea and its allies use CBI in this role. Hydromantes differs from both in having a uniquely proportioned and structured hyobranchial skeleton and associated musculature. Less extreme specializations for tongue projection are found in different combinations in three other groups. Finally, two distinct groups of generalized species having only limited tongue projection capabilities are recognized, each having a unique complex of inter-related features. Each of these eight groups is recognized and characterized as a functional mode, and hypotheses concerning the biomechanical meaning of the character complexes of each are formulated.     

猫儿山两种有尾两栖类消化道嗜银细胞比较观察

为探究有尾两栖类消化道内分泌细胞的特点,以分布于猫儿山保护区的猫儿山小鲵（Hynobius maoershanensis）和瑶山肥螈（Pachytriton inexpectatus）为研究对象,采用Grimelius银染法,对二者消化道嗜银细胞的形态特征、分布区域与分布密度进行了比较研究,为有尾两栖类消化道比较组织学和内分泌学研究积累基础资料,并为两栖类消化生理学研究提供形态学数据基础。结果显示,两种动物从食道至直肠均有嗜银细胞分布,分布型都呈波浪形,均在食道处分布密度（个/视野）最高,猫儿山小鲵为2.00 ± 0.69,瑶山肥螈为3.42 ± 0.31,在猫儿山小鲵回肠（1.45 ± 0.50）和瑶山肥螈在直肠（1.63 ± 0.97）分布密度最低。瑶山肥螈消化道各部位嗜银细胞的分布密度都高于猫儿山小鲵,两种动物嗜银细胞分布密度在食道、贲门、十二指肠和回肠中差异显著,但在胃体、幽门和直肠中差异不显著。对同一物种消化道不同部位嗜银细胞进行比较,猫儿山小鲵及瑶山肥螈的嗜银细胞分布密度高峰均出现在食道,其中,猫儿山小鲵食道与十二指肠、回肠、直肠差异显著（P < 0.05）,瑶山肥螈食道与其他各部位差异显著（P < 0.05）。嗜银细胞形状多样,有圆形、椭圆形、锥形和梭形等,可分为闭合型和开放型细胞。猫儿山小鲵生活环境多为沼泽地,富含淤泥、落叶,喜食蛙类蝌蚪、蚯蚓等个体较小且易消化的食物,瑶山肥螈生活环境为石块粗砂较多的山溪,以虾、蟹、螺等为食,这两种动物消化道嗜银细胞的形态特征和分布密度各具自身特点,可能与其生境及食性等因素有关。     

The larval hyobranchial apparatus of discoglossoid frogs: its structure and bearing on the systematics of the Anura (Amphibia: Anura)

The morphology of the larval hyobranchial apparatus of discoglossoid frog species representing the genera Ascaphus, Alytes, Bombina, and Discoglossus is described and the resulting characters were analysed cladistically. Seven species representing seven major lineages of frogs were included in the cladistic analysis of characters. Several changes in the terminology of the musculature are introduced, and a new interpretation of the subarcualis-muscle system is presented. The phylogenetic analysis suggest that the hyobranchial apparatus was substantially altered in the lineages leading to and within the Pipanura. This notably involved fusion, reduction and loss of skeletal structures and muscles, and splitting of certain muscles into muscle groups. The result confirm previous hypotheses based on the study of adults: discoglossoid species retain the most numlerous plesiomorphic characters among extant ianurans. The larval hyobranchial apparatus is in many features structrually similar to that of urodeles. Many of their character states were most likely present in the most recent common ancestor of all living forgs. The cladistic analysis of 31 characters of ithe larval hyobranchial apparatus supports major clades: Anura, Bombinanura, Pipanura, and Pelobatoidea + Neobatrachia. The cladiostic analysis and interpretation of larval characters is in part compatible with phylogenetic hypotheses based on characters of adults and rRNA sequences, but is in conflict with the Mesobatrachia and Archaeobatrachia concepts of other authors.     

A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata)

We examine phylogenetic relationships among salamanders of the family Salamandridae using approximately 2700 bases of new mtDNA sequence data (the tRNALeu, ND1, tRNAIle, tRNAGln, tRNAMet, ND2, tRNATrp, tRNAAla, tRNAAsn, tRNACys, tRNATyr, and COI genes and the origin for light-strand replication) collected from 96 individuals representing 61 of the 66 recognized salamandrid species and outgroups. Phylogenetic analyses using maximum parsimony and Bayesian analysis are performed on the new data alone and combined with previously reported sequences from other parts of the mitochondrial genome. The basal phylogenetic split is a polytomy of lineages ancestral to (1) the Italian newt Salamandrina terdigitata, (2) a strongly supported clade comprising the "true" salamanders (genera Chioglossa, Mertensiella, Lyciasalamandra, and Salamandra), and (3) a strongly supported clade comprising all newts except S. terdigitata. Strongly supported clades within the true salamanders include monophyly of each genus and grouping Chioglossa and Mertensiella as the sister taxon to a clade comprising Lyciasalamandra and Salamandra. Among newts, genera Echinotriton, Pleurodeles, and Tylototriton form a strongly supported clade whose sister taxon comprises the genera Calotriton, Cynops, Euproctus, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Taricha, and Triturus. Our results strongly support monophyly of all polytypic newt genera except Paramesotriton and Triturus, which appear paraphyletic, and Calotriton, for which only one of the two species is sampled. Other well-supported clades within newts include (1) Asian genera Cynops, Pachytriton, and Paramesotriton, (2) North American genera Notophthalmus and Taricha, (3) the Triturus vulgaris species group, and (4) the Triturus cristatus species group; some additional groupings appear strong in Bayesian but not parsimony analyses. Rates of lineage accumulation through time are evaluated using this nearly comprehensive sampling of salamandrid species-level lineages. Rate of lineage accumulation appears constant throughout salamandrid evolutionary history with no obvious fluctuations associated with origins of morphological or ecological novelties.     

Ontogenetic evidence for the Paleozoic ancestry of salamanders

The phylogenetic positions of frogs, salamanders, and caecilians have been difficult to establish. Data matrices based primarily on Paleozoic taxa support a monophyletic origin of all Lissamphibia but have resulted in widely divergent hypotheses of the nature of their common ancestor. Analysis that concentrates on the character states of the stem taxa of the extant orders, in contrast, suggests a polyphyletic origin from divergent Paleozoic clades. Comparison of patterns of larval development in Paleozoic and modern amphibians provides a means to test previous phylogenies based primarily on adult characteristics. This proves to be highly informative in the case of the origin of salamanders. Putative ancestors of salamanders are recognized from the Permo-Carboniferous boundary of Germany on the basis of ontogenetic changes observed in fossil remains of larval growth series. The entire developmental sequence from hatching to metamorphosis is revealed in an assemblage of over 600 specimens from a single locality, all belonging to the genus Apateon. Apateon forms the most speciose genus of the neotenic temnospondyl family Branchiosauridae. The sequence of ossification of individual bones and the changing configuration of the skull closely parallel those observed in the development of primitive living salamanders. These fossils provide a model of how derived features of the salamander skull may have evolved in the context of feeding specializations that appeared in early larval stages of members of the Branchiosauridae. Larvae of Apateon share many unique derived characters with salamanders of the families Hynobiidae, Salamandridae, and Ambystomatidae, which have not been recognized in any other group of Paleozoic amphibians.     

五种蝌蚪口器及舌鳃骨的结构比较

采用体视显微镜和骨骼双染色法对5种不同栖息环境的无尾两栖动物蝌蚪的口器和舌鳃骨的形态结构特征进行了观察。5种蝌蚪口器由唇齿行、唇乳突和角质颌等组成。舌鳃骨是由关联骨Ⅰ、关联骨Ⅱ、角舌骨、舌鳃骨盘和角鳃骨等骨骼组成。蝌蚪的梅氏软骨若较发达,其摄食方式可能为刮食;蝌蚪的舌鳃骨发达,其摄食方式则可能为滤食。角质颌、唇齿以及角鳃骨上鳃耙的出现显著增强了蝌蚪主动摄食能力和对食物与非食物的主动选择性。     

Ontogeny of the hyobranchial apparatus in the salamanders Ambystoma talpoideum (Ambystomatidae) and Notophthalmus viridescens (Salamandridae): The ecological morphology of two neotenic strategies

Comparison of metamorphosis of skull and hyobranchial system in two species of neotenic salamanders reveals two different types of neoteny. Ambystoma talpoideum is completely neotenic owing to delayed metamorphosis. Notophthalmus viridescens exhibits limited neoteny as a result of incomplete metamorphosis. Morphological details of neoteny are compared to life history in both species in order to discuss the ecological morphology of the two neotenic strategies. Comparisons to Taricha granulosa, Triturus vulgaris, and Ambystoma gracile indicate that these two strategies are widely employed and may represent familial patterns.     

A new genus of frogmouth (Podargidae) from the Solomon Islands – results from a taxonomic review of Podargus ocellatus inexpectatus Hartert 1901

The frogmouth taxon occurring on the Solomon Islands has been known as Podargus ocellatus inexpectatus , a subspecies endemic to four islands in the Solomon Islands of a species that also inhabits New Guinea and Australia. Our morphological, osteological and molecular studies support recognition of inexpectatus at the species level, and further reveal that it merits placement in its own genus, which we describe here. Compared with the two other extant podargid genera, inexpectatus does not seem to be more closely related either to Batrachostomus (confined to the Indo-Malayan faunal region) or to Podargus of the Papuan–Australian faunal region. We also review the specimen history of the Solomon Islands Frogmouth, and discuss what little is known about its ecology, natural history and distribution.