摘要:

The tapir‐sized late Early Eocene proboscidean,Numidotherium koholense, is the oldest known member of the mammalian order to which the living elephants belong. Morphology of the limb skeleton is reviewed and newly discovered elements are described, with emphasis placed on features considered to have a bearing on limb posture and locomotion. Structure of the shoulder joint and the fact that the antebrachium is fused in a supinated position, indicates that forelimb posture would have been of the abducted or semi‐sprawling type. The carpus, while exhibiting the typically proboscidean serial arrangement of carpals (no contact between unciform and lunar), also possesses a free os centrale. The presence of an os centrale and entepicondylar foramen in the humerus are unexpected eutherian plesiomorphies. The structure of the hip joint indicates an abducted hindlimb posture. In both the fore‐ and hindlimb, mechanisms exist at the major joints to cope with the complicated flexion‐extension paths typical of a semi‐sprawling gait. Both the carpus and tarsus are indicative of a plantigrade stance. This, in concert with an abducted limb posture, indicates that the gait in numidotheres contrasts markedly with the sub‐unguligrade, parasagittal gait of elephantiform proboscideans. The recent suggestion that Proboscidea have their origins in a cursorially adapted phenacodontid‐like stock receives no support from

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01487.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The aim of this study is to provide a general view of the adductor musculature of the alethinophidian snakes. The aponeurotic system present in anilioid snakes is here described as being also present in colubroid and booid snakes. Although modified in various groups, this aponeurotic system retains the same topographical pattern in the anilioids, booids and colubroids, and is thus hypothesized to be homologous. An analysis of the aponeurotic system and related muscular bundles within the alethinophidian snakes is given. A new terminology is proposed for the jaw adductor muscles where the muscles levator anguli oris and adductor mandibulae externus superficialis (proper) of snakes (sensuLakjer, 1926; Haas, 1962) retain these names even if this fails to reflect the presumed homologies with the bundles of the same name in lizards (see Rieppel, 1988b); the fibres originating from the temporal tendon in the Anilioidea, and presumed to form a bundle of composite nature (Rieppel, 1980b), are named the M. adductor mandibulae externus temporalis (lost by the Macrostomata); the M. adductor mandibulae externus medialis is a composite muscle in the Anilioidea (Rieppel, 1980b) which give rise to two different muscles in the ‘booids’, the M. adductor mandibulae externus medialis, pars anterior and the M. adductor mandibulae externus profundus, the former being secondarily lost by the Caenophidia which retains only fibres homologues of the 3b and 3c heads of the profundus layer of lizards; the so‐called M. adductor mandibular externus profundus of snakes (sensuLackjer, 1926; Haas, 1962) is also a composite muscle in the Anilioidea (Rieppel, 1980b), in the alethinophidians it is essentially made of fibres homologous with the posterior pinnate part of the medialis layer of lizards, and is here named the M. adductor mandibulae externus medialis, pars posterior. As a result from this analysis it follows that: (1) the Macrostomata are characterized by the downward extension of the fibres forming the M. adductor mandibulae externus medialis, pars anterior and the loss of the M. adductor mandibulae externus temporalis: (2) the Xenopeltidae are set apart from the remaining macrostomatan snakes by the retention of the M. levator anguli oris and of a well developed lateral sheet of the quadrate aponeurosis; (3) the ‘booids’ form a monophyletic group comprising only the Boidae and Bolyeriidae (with the exclusion of the Xenopeltidae and Tropidophiidae) which is characterized by a differentiated M. adductor mandibulae externus medialis, pars anterior inserting on the lateral surface of the compound bone via its own aponeurosis; (4) the Tropidophiidae are set apart from all other snakes by the peculiar course of their lateral head vein; however, they belong to the Caenophidia as they show a facial carotid artery which passes dorsally to the mandibular and maxillary branches of the trigeminus; (5) a possible additional character in favour of an Acrochordoidea + Colubroidea monophyletic unit may be given by the pattern of innervation of the jaw adductor muscles in these two taxa; (6) a new interpretation of the compressor glandulae muscular complex ofAtractaspisresulted in a morphologically similar pattern to that of the viperids; the phylogenetic implications of such similarity are discussed

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01488.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A morphometric and electrophoretic survey was conducted to examine taxonomic relationships among eight population samples of theRana narinacomplex from the Ryukyu Archipelago of Japan and Taiwan. Five discrete morphotypes are differentiated, and these showed considerable genetic differentiation from each other. From the available information, each of the five morphotypes is judged to represent a species, and three are described as new.Rana utsunomiyaorumsp. nov.andR. supranarinasp. nov.are sympatric in Ishigakijima and Iriomotejima islands of the Yaeyama Group, and differ from the other members by having a shorter hindlimb.Rana utsunomiyaorumis the smallest in the complex, whileR. supranarinais the largest.Rana amamiensissp. nov. occurs on Amamioshima and Tokunoshima islands of the Amami Group and, likeR. narinafrom Okinawajima of the Okinawa Group, has a long hindlimb; it differs from the latter species by having a larger body and relatively small tympanum. These two species differ fromR. swinhoanafrom Taiwan by having a narrower disk on the third finger. A key to known species of the complex is given. Further, syslematics of theR. narinacomplex withinRana, body size in the two sympatric species, and sexual dimorphism found in this complex are discussed.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01489.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The Asian aphid genusAnomalosiphum, comprising six species, is reviewed, redefined and redescribed. Descriptions of existing species are supplemented where necessary. Three new species,A. murphyi, A. philippinensisandA. tiomanensis,are described. Separate keys are provided to the alatae and apterae ofAnomalosipiumspecies. The relationship betweenAnomalosiphum, its most closely related genera and their host plants is briefly discussed.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01490.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY