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Hyoid Apparatus (hyoid + apparatus)
Selected AbstractsHyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyx jubatus) and domestic cat (Felis silvestris f. catus)JOURNAL OF ANATOMY, Issue 3 2002G. E. Weissengruber Abstract Structures of the hyoid apparatus, the pharynx and their topographical positions in the lion, tiger, jaguar, cheetah and domestic cat were described in order to determine morphological differences between species or subfamilies of the Felidae. In the lion, tiger and jaguar (species of the subfamily Pantherinae) the Epihyoideum is an elastic ligament lying between the lateral pharyngeal muscles and the Musculus (M.) thyroglossus rather than a bony element like in the cheetah or the domestic cat. The M. thyroglossus was only present in the species of the Pantherinae studied. In the lion and the jaguar the Thyrohyoideum and the thyroid cartilage are connected by an elastic ligament, whereas in the tiger there is a synovial articulation. In adult individuals of the lion, tiger and jaguar the ventral end of the tympanohyal cartilage is rotated and therefore the ventral end of the attached Stylohyoideum lies caudal to the Tympanohyoideum and the cranial base. In newborn jaguars the Apparatus hyoideus shows a similar topographical position as in adult cheetahs or domestic cats. In adult Pantherinae, the Basihyoideum and the attached larynx occupy a descended position: they are situated near the cranial thoracic aperture, the pharyngeal wall and the soft palate are caudally elongated accordingly. In the Pantherinae examined the caudal end of the soft palate lies dorsal to the glottis. Differences in these morphological features between the subfamilies of the Felidae have an influence on specific structural characters of their vocalizations. [source] Interspecific variation in sternohyoideus muscle morphology in clariid catfishes: Functional implications for suction feeding,JOURNAL OF MORPHOLOGY, Issue 3 2007Sam Van Wassenbergh Abstract Depression of the hyoid apparatus plays a crucial role in generating suction, especially in fishes with a dorso-ventrally flattened head shape. It is generally assumed that shortening of the sternohyoideus muscle, which connects the hyoid to the pectoral girdle, contributes to hyoid depression. However, a recent study on the clariid catfish Clarias gariepinus has shown that this muscle does not shorten but elongates during this phase through retraction of the pectoral girdle. Here, we test whether this pattern is general among clariid catfish, or if variation in the morphology of the sternohyoideus may result in a different sternohyoideus behavior during hyoid depression. First, sternohyoideus mass, effective cross-sectional area, fiber length and fiber diameter were measured and compared for four clariid species. Next, velocity and magnitude of hyoid depression during prey capture (from high-speed videos), as well as patterns of sternohyoideus strain were analyzed (from high-speed X-ray videos) in these species. While morphology and hyoid depression performance varied considerably among these species, only the species with the most massive sternohyoideus, Gymnallabes typus, showed shortening of the sternohyoideus muscle during the initial part of the expansive phase. The data for Channallabes apus demonstrate that increasing the magnitude of hyoid depression does not necessarily require a shortening of the m. sternohyoideus, as it shows elongation of this muscle during hyoid depression. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] THE AERODYNAMICS OF THE BRITISH LATE TRIASSIC KUEHNEOSAURIDAEPALAEONTOLOGY, Issue 4 2008KOEN STEIN Abstract:, The Kuehneosauridae (Late Triassic, Britain, USA) had remarkable adaptations, most notably their elongate mid-dorsal ribs that were presumably covered with a skin membrane in life. These lateral ,wings' have always been linked with some form of gliding adaptation, but quantitative studies have been limited. Here, we provide a thorough aerodynamic analysis of both genera of British kuehneosaurids based on theory and on experiments with life-sized models in a wind tunnel. Of the two genera, Kuehneosuchus, with elongate ,wings', was a glider, and Kuehneosaurus, with much shorter ,wings', was a parachutist. Kuehneosuchus most probably had highly cambered wings and no additional skin membranes on hands or feet, nor did it have a cruropatagium. Lappets on the hyoid apparatus, as seen in Draco, were probably present to enhance pitch control. Kuehneosuchus was capable of gliding at angles (,) between 13 and 16 degrees, at speeds between 7 and 9 m/s, and was probably very manoeuvrable when airborne. Kuehneosaurus was capable of parachuting (, > 45 degrees) at speeds between 10 and 12 m/s. It is unclear whether the British kuehneosaurid material represents two genera, as assumed here, two species of one genus, or sexual dimorphs of a single species, where the gliding Kuehneosuchus was the male, which used its gliding and perhaps highly coloured ,wings' to display to the parachuting Kuehneosaurus. [source] | ||||||||||