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Treehugger
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Homework Statement
I have to write a ~2000 word essay using principles of fluid mechanics to address whether or not the frill on Triceratops is mainly for behavioral display or for thermoregulation. I'm not really that proficient in my knowledge of physics and have been struggling with quizzes and tests in this class, so I'm hoping to do well on this paper as it's a large chunk of my grade. I have a good source to back up what my professor taught on using fluid dynamics to show how the frill may have been used for thermoregulation, but I feel as though most of my paper is going to end up being on this study, which was not done using fluid mechanics but by studying the bone structure and heat flow measured with oxygen isotopes. I'm worried I may be making errors on what I say regarding physics, and about my lack of knowledge to expand on what was said about fluid mechanics. Help pointing out errors, correcting them, and expanding upon fluid mechanics would be greatly appreciated.
This is a video of my professor explaining his work using models and fluid mechanics to predict whether the frill was used for thermoregulation.
The Attempt at a Solution
This is what I have so far.
The Triceratops is a well known dinosaur from the Ceratopsidae family, which are characterized by their horns and frills. Past studies, such as The Behavioral Significance of Frill and Horn Morphology in Ceratopsian Dinosaurs by Farlow and Dodson explain the presence of the horn and frill as instrumental in dominance and sexual displays, and in defense. However if thermodynamics and physics are taken into account then one can say that it is more likely that the frill was used to regulate body temperature, and that behavioral use was a secondary function. Triceratops were large homeotherms, and as such had a low thermal diffusivity of body tissues. Large animals have much higher thermal inertias and the Triceratops has a high volume to surface area ratio, so they would therefore lose body heat very slowly. If this animal was exposed to high ambient temperatures or carried out sustained activity, it would likely experience core hyperthermia. The central nervous system (CNS) is very sensitive to high temperatures, and therefore organisms develop ways of moderating their temperatures via physiology to effectively cool the brain to prevent thermal damage to the CNS. The horns of modern bovids are known to play a small part in heat dissipation (Taylor 1966) and therefore it is likely that they did such in the horns of Ceratopsids as well. The frill found in members of Certopsidae has a large surface area and were highly vascularized, and due to this would be useful in dissipating heat from the body If these structures were used as “biological heat radiators” (cite) then they would have a way to radiate excess heat from the body into the environment and prevent hyperthermia and harm to the brain. (Wheeler 1978)
As Triceratops are extinct, it is not possible to use one in studies to discover the actual use of the frill. However, using the Reynold's number one can estimate how thermodynamics acting upon a small triceratops model might apply to the extinct dinosaur. By calculating a Reynold's number for the small model in water using the size of the model and velocity of water, you can match that Reynold's number to the actual historic dinosaur at a certain wind velocity.
Turner, a physiologist at SUNY-ESF, performed a small experiment using a calculated Reynold's number, a small 0.18 meter (m) Triceratops model, and fluorescent dye in water moving at a velocity of 0.03 m/s to visualize how air at a velocity of 0.01 m/s would affect a 9 m Triceratops. He found that when the water was angled towards the dinosaur model from high off the ground, the frill diverted air upwards off the back. Closer to the frill produced a vigorous generation of turbulent vortexes on the frill margin, and retained these along the rear surface of the frill. Further down the forehead produced a strong retrograde flow. Turbulence was generated when the flow was coming at the Triceratops from eye level, and produced vigorous turbulence behind the frill. When the horn was involved a retrograde flow was produced along the snout and horn. When the flow was lateral to eye level, the frill diverted air flow towards itself. When the flow was coming from behind it promoted heat exchange along the Triceratops' face. Models with smaller frills did not generate much turbulence when the flow was directed at their face, but from behind generated considerable turbulence. This brings to the conclusion that when a Triceratops is standing into the wind there is a strong generation of turbulence along frill margins. When downwind, there is a strong retrograde flow on the front surface of the frill. Both of these promote heat exchange.
A study done by various scientists, published in 1998 in the Journal of Vertebrate Paleontology, specifically set out to research what part the frill and horns of Triceratops might play in thermoregulation... (this is where I'm starting implementing the other study, but I haven't gotten to it as of yet.)