Inhalt

1 Introduction.- 1.1 Objectives of this Study.- 1.2 Literature Review.- 1.3 Theoretical Concepts: Questions and "Answers".- 1.3.1 Description and Representation.- 1.3.2 Comparative Approach, Homology, Systematics, and Phylogeny.- 1.3.3 Functional Approach.- 1.3.4 Ecomorphology.- 1.4 Basic Functional Concepts of the Avian Middle Ear: The Transfer Function.- 1.4.1 Area Ratio.- 1.4.2 Lever Systems.- 1.4.3 Curved Membrane and Resonance Effects.- 1.4.4 Impedance of the Middle Ear.- 1.5 Evolutionary History of Middle Ear Structures.- 1.5.1 Homologies of the Avian Middle Ear and the Hyoid Arch.- 1.5.1.1 Stapes.- 1.5.1.2 Tympanic Process of the Extracolumella.- 1.5.1.3 Processus supracolumellaris.- 1.5.1.4 Processus infracolumellaris.- 1.5.2 Phylogenetic Relationship of Palaeognathous and Basic Neognathous Birds.- 2 Materials and Methods.- 2.1 Species List.- 2.2 Macroscopic Dissections.- 2.3 X-Ray Computed Tomography.- 2.4 Morphometry.- 2.5 Microscopic Investigations.- 2.5.1 Serial Sections.- 2.5.2 Transmission Electron Microscopy.- 2.5.3 Three-Dimensional Reconstructions.- 2.5.4 Computer-Aided Three-Dimensional Reconstructions.- 2.6 Nomenclature, Synonyms, and Abbreviations.- 3 Results.- 3.1 Species Biology.- 3.1.1 American Rhea (Rhea americana).- 3.1.2 Crested Tinamou (Eudromia elegans).- 3.1.3 Emu (Dromaius novae-hollandiae).- 3.1.4 Cassowary (Casuarius bennetti/Casuarius casuarius).- 3.1.5 Kiwi (Apteryx australis).- 3.1.6 Ostrich (Struthio camelus).- 3.1.7 Barred Button Quail (Turnix suscitator).- 3.2 External Ear Opening: Position, Ear Covers, Form, and Width of Opening.- 3.3 External Auditory Meatus (Meatus acusticus externus): Position and Course, Bordering Structures, and Relation to Fascia and Muscles.- 3.4 Osteology of the Tympanic Region.- 3.5 Tympanic membrane (Membrana tympanica): Position, Orientation, Fixation, and Histology.- 3.6 Tympanic Recesses and Pneumatization of the Neurocranium.- 3.7 Siphonium and Pneumatization of the Mandible and the Quadrate Bone.- 3.8 Pharyngotympanic Tube.- 3.9 Arthrology of the Quadrate Bone.- 3.10 Columella: Stapes and Extracolumella.- 3.11 Ligaments of the Middle Ear.- 3.11.1 Ligamentum ascendens.- 3.11.2 Ligamentum columello-quadratum (Platner's Ligament).- 3.12 Muscles of the Middle Ear.- 3.12.1 Musculus stapedialis.- 3.12.2 Musculus paratubalis.- 3.13 Nerves.- 3.14 Paratympanic Organ.- 3.15 Arteries.- 4 Discussion.- 4.1 Towards a Functional Analysis of the Avian Middle Ear.- 4.1.1 Morphological Amplification Function.- 4.1.2 Morphological Impedance.- 4.2 Phylogenetic Implications.- 5 Summary.- 6 References.- 7 Subject Index.- 8 List of Abbreviations and Synonyms Used in Avian Middle Ear Studies.