Physiological Adaptations of the Plesiosaur for ?Holding its Breath? :: essays research papers

Physiological Adaptations of the plesiosaurus for Holding its BreathOne hundred and fifty million eld ago, large aquatic species of reptile such as the Plesiosaur reign the ocean, and were pre-eminent predators of the sea. The branch of now extinct Plesiosaurs, or near lizards, evolved into variant closely related species specialised to take different niches in the food chain. such(prenominal) species of Plesiosaur include the phenotypically similar Plesiosauroid and Pliosauroid. The physiological adaptations of the long necked variant, the Plesiosauroid, as it relates to deep sea diving, will be addressed in depth. atomic number 8 breathing lungs are a universal trait of class reptilia. As such, it would beat been necessary for the Plesiosauroid - a marine reptile, to return to the ocean rebel to inhale air. Oxygen expenditure in reptiles is proportional to strenuosity of travelling (Frappell, Schultz & Christian, 2002). in that respectfore the Plesiosauroid must have held physiological traits that enabled the species to avoid oxygen famine while hunting deep-sea dwelling prey. This essay will line the hypothesised respiratory, circulatory, pulmonary and sensory attributes of the Plesiosauroid as they relate to diving. These hypotheses will be back up by investigating the physiological adaptations of the Plesiosaurs biological analogues, and the expected value of similar adaptations in the former will be speculated upon.Reptiles have a low metabolic rate they consume energy, and therefore oxygen, slowly. According to Robinson (1975), Plesiosauroids were support swimmers with lower flipper aspect ratios and drag-causing long necks. Massare (1988) made the same conclusion, since the hydrodynamic properties of the Plesiosauroids indicate the species moved no faster than 2.3 metres every second. Therefore, the species was confronted by a conundrum it sought to dive hundreds of metres to hunt its prey yet was constrained, by virtue of its body shape, to travel at slow speed. Invariably, the animal would have been required to forgo oxygen for periods of more than a minute, while belongings the presence of mind to hunt.Fortunately, when making its descent of hundreds of metres, the Plesiosauroid would have been able to crop traits possessed by many of the reptile class. Many reptiles hold the tycoon to temporarily slow their heart rate to reduce their oxygen consumption, via bradycardia. This solution may be caused by low temperatures, such as is be deeper in the ocean, or may be voluntarily triggered by the animal. There would be no need for the Plesiosauroid to retain all of its oxygen-consuming faculties during the long descent.