Rhineura

Number of Pages: 2Integrative BiologyGeological Science

The characteristics and affinities of the Amphisbaenia

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75528/1/j.1096-3642.1978.tb00376.x.pd

Questions in Crocodilian Physiology

Morphologists, physiologists, behaviourists and ecologists have traditionally asked different and often mutually exclusive questions within their different conceptual frameworks. Only the concept of natural selection and the idea that the animals have been modified for one or another mode of life history provide a common denominator or common framework for comparison. This approach also suggests that the observed responses to disturbance and to the multiple facies of the biotope are likely to be adaptive and that such adaptation is to be looked for. Finally one can see that selection is apt to differ during the stages of ontogeny and that age-specific selection is likely to produce age-specific adaptation. Three cautions then apply to the interpretation of data now in the literature. Each reflects the need to treat the animal holistically in an adaptive context

Quantitative assay of electromyograms during mastication in domestic cats ( Felis catus )

Mastication has been studied by cinematography with synchronized electromyography (computer quantified and analyzed), while unanesthetized, freely feeding cats ( Felis catus ) were reducing equivalent-sized chunks of raw and cooked beef and cooked chicken. Cats reduce food on one side at a time, and their chewing cycles show both horizontal and anteroposterior deflections. Food objects are shifted from side to side by lateral jerks of the head and movements of the tongue. During the opening phase, the lower jaw is rotated relatively straight downward, and the digastric muscles are active in bilateral symmetry. Near the end of opening, the head jerks upward, both zygomaticomandibulares start to fire, and opening acceleration of the mandible decreases. Closing starts with horizontal displacement of the mandibular canines toward the working side, accompanied by asymmetrical activities from the working side deep temporalis and the balancing side medial pterygoid, as well as a downward jerk of the head. As closing proceeds, the mandibular canines remain near the working side and the working side zygomaticomandibularis and deep masseter are very active. Near the end of closing, the mandibular canine on the working side moves toward the midline, and adductors, digastrics, and lateral pterygoids of both sides are active. The adductors of the working side are generally more active than those of the balancing side. During a reduction sequence, the number and shape of the masticatory cycles, as well as movements of the head, during a reduction sequence are affected significantly by food type. As reduction proceeds, the duration of bite and the muscular activity (as characterized by number and amplitude of spikes) change significantly among muscles of the working and balancing sides. The adductors of the working side are generally most active when cats chew raw beef, less for cooked beef, and least for cooked chicken. In general, the adductor activity reflects food consistency, whereas that of the digastrics and lateral pterygoids reflects more the vertical and lateral displacements of the mandible. Statistical analysis documents that the methods of electrode insertion and test give repeatable results for particular sites in different animals. Thus, it should be possible to compare these results with those produced while other mammalas are masticating.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50273/1/1051630304_ftp.pd

Functional Aspects Of The Evolution Of Frog Tongues

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137442/1/evo00952.pd

Small species from southern South America commonly identified as Amphisbaena darwini

p. 187-260, [9] p. of plates : ill., maps ; 27 cm.Includes bibliographical references (p. 258-260)

Common water snake of southeastern South America

58 p. : ill., maps ; 24 cm.Includes bibliographical references (p. 42-44)

Vertebrate Air Breathing Arose In Fresh Waters And Not In The Oceans

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137418/1/evo00662.pd

Amphisbaenids

18 p. : ill., map ; 24 cm.Includes bibliographical references (p. 17-18)

Review of the amphisbaenid genus Leposternon

p. 381-464 : ill., maps ; 27 cm.Includes bibliographical references (p. 459-464)."The present study, based on more than 800 specimens in some 40 collections and on a review of all references in the literature, reduces the more than 24 named forms of the South American amphisbaenian genus Leposternon to seven, six of these having been previously named, and the seventh thus far known from only a single specimen. The species Leposternon microcephalum occupies almost the entire generic range, whereas the remaining forms (L. infraorbitale, L. octostegum, L. polystegum, L. scutigerum, L. wuchereri) appear to be more or less sympatric to it. The single, yet unnamed individual of the seventh form stems from Goiás, within the range of L. infraorbitale. The variability of integumentary architecture is much greater in this genus than in those other amphisbaenians thus far examined. The cephalic segmentation of some of the species in particular shows remarkable local variance, and the dermal-vertebral ratio is most irregular, departing drastically from the value of two, which is almost universal in other species of the order; some local variants particularly would seem to provide raw material for several kinds of interesting supplementary studies"--P. 459