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Full-Text Articles in Biology
Morphological And Behavioral Traits Associated With Locomotion In Lizards, Chase T. Kinsey
Morphological And Behavioral Traits Associated With Locomotion In Lizards, Chase T. Kinsey
Electronic Theses and Dissertations
Morphology, locomotion, and behavior are co-adapted to optimize performance and ultimately fitness. Successfully navigating a complex environment is dictated by an animal’s locomotor behavior, and for some behaviors, its locomotor performance. The locomotor performance of an organism is directly related to the form and function of the structures involved in locomotion such that movement is efficient – that is, minimal loss of energy. The first chapter of this thesis focuses on the effects of obstacle placement and forelimb position on facultative bipedalism. Placing an obstacle beyond a lizard’s acceleration threshold did not affect the frequency of bipedal posture. Furthermore, the …
Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski
Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski
Electronic Theses and Dissertations
Trachemys (Testudines: Emydidae) represents one of the most well-known turtles today. The evolution of Trachemys, while being heavily documented with various fossil representatives, is not well understood. Numerous fossils from the Gray Fossil Site in northeastern Tennessee are helping to elucidate the taxon’s evolution. The fossil Trachemys at the Gray Fossil Site represent a new species. A review of previously named Trachemys taxa reveals that a huge majority of them are not valid or have been previously misinterpreted. A phylogenetic analysis preformed on modern emydids and supposed fossil representatives of those genera also shows the evolution of a portion …
The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self
The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self
Electronic Theses and Dissertations
The ability to efficiently move over uneven terrain is critical for most terrestrial animals. Bipedal running is common in lizard species, however the biological advantage of a bipedal running posture remains uncertain. I examined the hypothesis that a bipedal posture is advantageous when crossing obstacles. Particularly, I determined whether kinematic adjustments differ among four focal species with contrasting body forms and ecology. I also examined how sprint speed changed when crossing obstacles with a quadrupedal versus a bipedal posture. I quantified kinematics from high-speed video (300 frames/second) of lizards running down a 3m runway both with and without the presence …
Adaptive Responses Of Branchial Morphology To Hypoxia In The Neotropical Electric Fish Genus Brachyhypopomus, Leilani B. Pathak
Adaptive Responses Of Branchial Morphology To Hypoxia In The Neotropical Electric Fish Genus Brachyhypopomus, Leilani B. Pathak
Electronic Theses and Dissertations
Many tropical aquatic environments worldwide are characterized by intermittent or prolonged hypoxia (low dissolved oxygen). Nevertheless, many tropical freshwater fishes are able to inhabit these challenging environments via a range of morphological, physiological and behavioral adaptations. Brachyhypopomus is a diverse genus of weakly electric fishes represented by 28 known species distributed from Panama to Argentina. 17 species are restricted to permanently normoxic habitats (blackwater rivers and terra firme streams), eight species are restricted to seasonally or perennially hypoxic habitats (whitewater floodplains of large tropical rivers or permanent swampy habitats), and three species are eurytopic (occur in both seasonally hypoxic and …