Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Ontogenetic staging of the mammalian dentition, and its value for assessment of homology and heterochrony (1993)
    Springer
    Journal of mammalian evolution 1 (1993), S. 269-282 
    Details
    ISSN: 1573-7055
    Keywords: ontogeny ; dentition ; heterochrony ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A closely graded system of ontogenetic staging is presented for changes that occur during early development of the dentition in therian mammals, up to and including early phases of the calcification process. Such a precise staging system is essential to detect differences in the time of onset and subsequent differentiation of individual tooth loci within the jaws of a single species, and within supraspecific taxa. Analysis of the evolutionary significance of these developmentalheterochronies can play a valuable role in the assessment of serial homology in the therian dentition, and it provides additional insight into the nature and pattern of tooth loss during evolution. Following the description and illustration of bud, cap, and bell substages, examples are presented from the ontogeny of the primary dentition in macroscelidids and hyracoids. These demonstrate the use of this staging system for assessing the serial homology of modified teeth such as “premolariform” canines and the role of developmental retardation in the evolutionary loss of primary and secondary teeth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01041667
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Molecular evidence for mammalian evolution: Congruence and conflict with “traditional” phylogenetic hypotheses (1994)
    Springer
    Journal of mammalian evolution 2 (1994), S. 1-2 
    Details
    ISSN: 1573-7055
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01464346
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Suprafamilial relationships within marsupialia: Resolution and discordance from multidisciplinary data (1994)
    Springer
    Journal of mammalian evolution 2 (1994), S. 255-283 
    Details
    ISSN: 1573-7055
    Keywords: marsupial phylogeny ; multidisciplinary data
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Selected characters of the cranioskeletal, dental, neuroanatomical, reproductive, lymphoid, and developmental systems that are known for most or all extant marsupial families are reviewed and analyzed for their abilities to corroborate higher-level hypotheses of suprafamilial relationships among extant marsupials. In addition, relatively conservative nucleotides from the mitochondrial 12S rDNA gene (obtained from the recent study by Springeret al., J. Mammal. Evol. 2, 85–115, 1994) were incorporated into the same character analysis. The ancestral morphotype for each marsupial family and each character was reconstructed, using the reconstructed eutherian and therian morphotypes for outgroup comparisons. In addition, ontogenetic data, stratigraphic position of fossils, and form-functional considerations were used, whenever feasible, to assess character state polarity of anatomical traits. Despite missing data from some families and many genera, this preliminary and modified “total evidence” approach helps to identify several well corroborated higher taxa, including Diprotodontia, Vombatiformes, and Macropodoidea, and it provides modest support for Ameridelphia, Australidelphia, and Syndactyla. An important conclusion is that no single data set is capable of resolving all suprafamilial relationships among marsupials. Suggestions are also presented for future multidisciplinary approaches to help resolve several polychotomies that have remained resistant to phylogenetic analyses of single data sets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01464277
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ontogeny and homology of the dentition in dasyurid marsupials: Development inSminthopsis virginiae (1996)
    Springer
    Journal of mammalian evolution 3 (1996), S. 327-364 
    Details
    ISSN: 1573-7055
    Keywords: ontogeny ; homology ; dentition ; dasyurids ; heterochrony ; marsupials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Histological analysis of an ontogenetic series of the dasyurid marsupial,Sminthopsis virginiae, from birt to 60 days old, was undertaken to assess the developmental homologies of the deciduous and successional teeth. This period covers the time from the initiation of all teeth as epithelial buds up until the time of early eruption of some teeth. In addition, two older specimens, aged 81 and 97 days, were examined to provide additional information on the state of differentiation of the unerupted third premolar. In the postcanine dentition, only a single tooth position, dP3, was characterized by the later development of a replacing successional tooth (P3), following developmental pathways identical to those in eutherian mammals. In contrast, the anterior dentition is characterized by the formation of rudimentary, nonerupting deciduous incisors and canines, and by the accelerated development of normal, erupting successional incisors and canines in both jaws. Comparison of relative developmental stages for each tooth position throughout its preeruptive ontogeny suggests thatheterochrony (both developmental acceleration and retardation) has played an important role in the evolutionary history of the dasyurid dentition. Differing aspects of this phenomenon are identified and discussed for the anterior dentition, the anterior two premolars, P3, and the lower molars. Further evidence is presented to corroborate the identification of the anterior two premolars in the adult as dP1 and dP2, based on the relative retardation of their initiation and their lack of successor tooth germs. This developmental heterochrony has probably occurred in all three-premolared marsupials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02077449
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Ontogenetic Evidence for Dental Homologies and Premolar Replacement in Fossil and Extant Caenolestids (Marsupialia) (2000)
    Springer
    Journal of mammalian evolution 7 (2000), S. 109-127 
    Details
    ISSN: 1573-7055
    Keywords: marsupials ; dental ontogeny ; deciduous premolars ; Caenolestidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract It is generally accepted that the South American marsupial family Caenolestidae is characterized in part by the absence or noneruption of the third deciduous premolar (dP3) in both jaws, although juvenile stages have rarely been identified in extant or fossil representatives of the family. Published illustrations of the dentary of the Miocene caenolestid Stilotherium suggested to us, however, that P3 erupted relatively late during ontogeny, after the eruption of M4. In extant marsupials, this eruption sequence appears to represent the plesiomorphic state and this pattern is generally associated with the eruption of dP3 earlier in ontogeny, and its subsequent replacement by the erupting P3. Therefore, we suspected that a dP3 erupted in earlier ontogenetic stages of caenolestids; to test this hypothesis we searched the mammalogy collections of three museums for evidence of dP3 in juvenile specimens of caenolestids. Examination of more than 180 specimens of the three extant genera of caenolestid marsupials resulted in the identification of only nine juvenile or subadult stages of dental eruption. Seven specimens of Caenolestes and Rhyncholestes corroborated our hypotheses of late eruption of P3 in Caenolestidae. In addition, the two youngest specimens of Caenolestes possessed a tiny, rudimentary dP3, measuring about 0.4 to 0.5 mm in greatest length, associated with a mesiolingual eruption pit containing the apex of the larger P3 in very early phases of eruption above the alveolar margins. The tiny dP3 is clearly nonfunctional in occlusion, and it is questionable whether it erupted above the gun margins in life. Comparison of the dentaries of subadult caenolestids with four dentaries of the Miocene genus Stilotherium corroborated our initial impression that the fossil genus exhibited evidence of a late-erupting P3, comparable to the condition in extant caenolestids. We suggest that examination of other specimens of juvenile dentitions, skulls, and skeletons in museum collections can provide additional insight into the developmental and evolutionary biology of mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009406632509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Phylogenetic Relationships Between the Orders Artiodactyla and Cetacea: A Combined Assessment of Morphological and Molecular Evidence (1998)
    Springer
    Journal of mammalian evolution 5 (1998), S. 127-182 
    Details
    ISSN: 1573-7055
    Keywords: Artiodactyla ; hippopotamuses ; Cetacea ; morphology ; cytochrome b ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A character analysis of selected conservative morphological traits from extant and fossil artiodactyls and cetaceans was combined with a similar analysis of conservative nucleotide positions from the complete mitochondrial cytochrome b sequences of available extant artiodactyls, cetaceans, sirenians, perissodactyls, and other mammals. This combined analysis focuses on the evidence that supports conflicting hypotheses of artiodactyl monophyly, including the affinities of hippopotamids and the monophyly or paraphyly of odontocete cetaceans. Highly conserved morphological traits of the astragalus and deciduous dentition provide strong corroboration of artiodactyl monophyly, including extant and fossil hippopotamids. In contrast, cytochrome b gene sequences are incapable of confirming this monophyly, due to excessive homoplasy of nucleotide and amino acid traits within extant Eutheria. In like manner, highly conserved and uniquely derived morphological features of the skull and auditory regions provide robust corroboration of Odontoceti monophyly, including extant and fossil physeteroids. Several nucleotide similarities do exist between physeteroids and mysticetes; however, most are either silent third-position transversions or occur also in two or more odontocete families. We suggest that increased taxon sampling, combined with functional considerations of amino acids and their secondary structure in protein-coding genes, are essential requirements for the phylogenetic interpretations of molecules at higher taxonomic levels, especially when they conflict with well-supported hypotheses of mammalian phylogeny, corroborated by uniquely derived morphological traits from extant and fossil taxa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020501622015
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The fine structure of the placental villi of the rhesus monkey(Macaca mulatta)This work was supported by NIH Research Fellowship 7 F2 HD-19, 136-01A1, and NIH grant HD 00277-11 during the period of a postdoctoral fellowship at the Department of Anatomy, University of Wisconsin Medical School, Madison, Wisconsin. (1970)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 167 (1970), S. 141-163 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Placental villi were obtained from monkeys at the Wisconsin Primate Research Center during 50-150 days gestation. As in the human, the villi consist of a vascular mesenchymal core surrounded by inner cytotrophoblastic and outer syncytiotrophoblastic layers.The syncytiotrophoblast contains abundant rough endoplasmic reticulum and a well developed Golgi complex consisting of stacked lamellae and diffuse vesicles. An asymmetrical distribution of ribosomes occurs on RER cisternae associated with mitochondria. Branched microvilli frequently bear dilated tips and resemble stereocilia. Cytoplasmic tufts and microvilli increase the surface area, and the base of the tuft usually contains a large membrane-bound vacuole with a flocculent inclusion of low electron density. These vacuoles are lacking after 100 days. In later stages the syncytiotrophoblast bears irregular microvillous processes and specialized attachment sites at its contact with the basal lamina.Hofbauer cells in the villus core contain numerous large vacuoles, coated pinocytotic vesicles and smooth vesicles apparently derived from ER; the latter are sometimes fused to the large vacuoles. Hofbauer cells appear to be derived from undifferentiated mesenchymal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091670203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The development of the chorio-allantoic placenta of the African scaly-tailed squirrels (family Anomaluridae)This study was supported by an award from the Lalor Foundation. (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 130 (1971), S. 159-177 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The affinities of the isolated rodent family Anomaluridae are unknown. Both sciuromorphous and specialized features characterize its placental morphology. A shallow preplacenta consists of inner cytotrophoblastic and outer syncytiotrophoblastic layers. The early chorio-allantoic placenta consists of the following zones: a hemochorial zone of interconnected trabeculae, lined with outer syncytiotrophoblastic and inner cytotrophoblastic layers; anchoring trabeculae attached to a zone of decidual giant cells, with the giant cells gradually disappearing in later stages; a zone of acidophilic, PAS-positive necrotic material underlying the giant cells; and a zone of decidua basalis underlying the necrotic zone and probably contributing to it. An allantoic vesicle lies on the surface of the early placenta; it is reduced in later stages. The bilaminar omphalopleure persists, and it is attached to the margins of the placental disc. The fetal membranes of Anomalurus are most similar to those of sciuromorphs, Pedetes and Ctenodactylus; this may be the result of primitive retentions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001300204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The development of primordial and definitive amniotic cavities in early rhesus monkey and human embryos (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 144 (1975), S. 149-167 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Re-examination of early rhesus monkey and human embryos in the collection of the Carnegie Institution of Washington suggests that the mechanism of amniogenesis in both is basically similar to that of the hedgehog and vespertilionid bats. A primordial amniotic cavity develops by cavitation within the embryonic mass of 10-day rhesus monkey, and 7-day human, blastocysts. This primordial cavity has no relationship initially with the overlying trophoblast, contrary to earlier reports. Subsequently, there is a thinning and peripheral spreading of the epiblastic roof of the primordial cavity, resulting in partial opening of the roof and formation of a slightly cupped embryonic disc. The resulting space is not homologous with the primordial amniotic cavity; instead, it is a transitory tropho-epiblastic cavity. The definitive amniotic epithelium forms by the upfolding and mitotic proliferation of the margins of the epiblastic disc; this process is completed in 11-day rhesus, and 9-day human, blastocysts.Amniogenesis by cavitation is associated with the persistence of polar trophoblast following implantation, and it is suggested that this cavitation process may be essential for providing a free epithelial surface for the morphogenetic movement of epiblastic cells during subsequent formation of the primitive streak.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001440204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Development and phylogenetic significance of the fetal membranes and placenta of the African hystricognathous rodents Bathyergus and Hystrix (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 162 (1981), S. 265-285 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Morphogenesis of fetal membranes in African and American hystricognathous rodents is essentially the same, even in the possession of such uniquely derived features as a subplacenta and a capillary ring on the inverted yolk sac, features that are unknown in any other rodent group. This is good evidence that the African and American hystricognaths comprise a monophyletic group. Certain interesting features of the decidua, decidual giant cells, periplacental bilaminar omphalopleure, and epamnion are described in Bathyergus and Hystrix. Of special interest in Bathyergus is the widespread decidualization of the uterine connective tissue, even that of the myometrium and perimetrium; and the presence of numerous, usually binucleate, decidual giant cells.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001620307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...