摘要:

Two new species belonging to the genusAldisawere found in the cold‐temperate N Pacific waters off southern British Columbia, Canada. These species are sympatric withAldisa cooperiRobilliard&Baba,1972. The cold‐temperate Atlantic waters off the coast of S Africa revealed two new, sympatric species ofAldisa, the first recorded from the southern hemisphere. The morphological characteristics of these four new species are described in detail. As many known species ofAldisaare incompletely described, redescriptions ofAldisa binotataPruvot‐Fol, 1953;Aldisa cooperiRobilliard&Baba, 1972;Aldisa pikokaiBertsch&Johnson, 1982, andAldisa zetlandica(Alder&Hancock, 1854) are provided. Specimens ofAldisa banyulensisPruvot‐Fol, 1951, andAldisa berghiVayssiere, 1901, were unavailable. A key to the 11 presently recognized species ofAldisais included and the characteristics and relationships of this genus are di

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1985.tb01799.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

This paper suggests that, on the basis of ontogenetic change in intestinal coiling pattern, four types and four subtypes could be recognized within 20 species of epilithic algal‐feeding cichlids in Lake Tanganyika. The phylogenetically useful anatomical features characterizing each type are as follows.Petrochromistype: torsion of the intestinal tract generally occurs at Stage 5 Intersecting Point (IP), and the haplochromine loop and a two‐loop coiling system are observable.Cyathopharynxtype: the value of IP becomes 7 before torsion occurs, and the coiling system changes qualitatively from one‐loop to two‐loop types.Asprotilapiatype: torsion occurs at Stage 5 IP, and a one‐loop coiling system is retained throughout ontogeny.Telmatochromistype: no torsion occurs, and a one‐loop coiling system is retained throughout ontogeny. Within thePetrochromistype, each of the four subtypes is characterized by the following features.Petrochromissubtype: the rostrally directed haplochromine loop has its rostral part situated to the right side of the stomach in the adult stage.Pseudosimochromissubtype: a circular haplochromine loop is present.Eretmodussubtype: the haplochromine loop tends to be prolonged and bends through 90 or 180 further counter‐clockwise.Tropheussubtype: torsion occurs

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1985.tb01800.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A new specimen ofKingoria nowacki(von Huene) with a complete pelvic girdle and hindlimb is reconstructed and the method of locomotion analysed. It is concluded that the hindlimb was modified from the normal dicynodont pattern in a direction comparable to that of advanced mammal‐like reptiles which are presumed to have given rise to mammals. The pectoral girdle also had a modified form, but the humerus was probably conservative in its morphology. The hindlimb stride relied on protraction and retraction to effect movement while the forelimb relied on long axis rotation of the humerus. Possible reasons for the difference in morphology and function of the fore‐and hindlimbs are discussed, and a functional sequence for the generation of theKingoriapelvic girdle from that of other Permian dicynodonts is sugges

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1985.tb01801.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The feeding mechanisms of lampreys and hagfish, as described in the literature, are reviewed. Although current opinion generally holds that these two groups have very different feeding mechanisms, eleven synapomorphous features are recognized, and the underlying anatomical homologies are suggested. In these features, the two groups clearly share none of the anatomy of gnathostomes, and it is concluded that the cyclostomes constitute a monophyletic group, the sister‐group of the gnathostome

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1985.tb01802.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY