NoCoPilot
Posts : 20163 Join date : 2013-01-16 Age : 69 Location : Seattle
| Subject: Dinosaurs With Feathers Tue Feb 13, 2018 8:35 pm | |
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Last edited by NoCoPilot on Sat Jul 10, 2021 2:35 pm; edited 2 times in total |
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NoCoPilot
Posts : 20163 Join date : 2013-01-16 Age : 69 Location : Seattle
| Subject: Re: Dinosaurs With Feathers Wed Jun 09, 2021 10:55 am | |
| Birds have a cloaca, and excrete their solid and liquid wastes together in a wet paste. Nobody knows if dinosaurs, from whom birds descended, used a similar excretory technique. Although it's assumed they did: https://www.newscientist.com/article/2258023-dinosaur-fossil-with-preserved-genital-orifice-hints-how-they-mated/ - Quote :
- We all know about many of the features of birds that allow them to master the air: hollow bones, light yet strong feathers for producing lift and thrust, and streamlined bodies. However, other adaptations for flight are subtler and perhaps unexpected. The various organ systems for birds all contribute to make a bird a consummate flying machine.
Let’s start with the urinary or excretory system. The function of any excretory system is to rid the body of nitrogen-containing wastes from the breakdown of proteins. The most common waste product is ammonia, a toxic material.
For fish and invertebrates that live in freshwater or the sea, it’s pretty easy to get rid of the ammonia by producing a large quantity of dilute urine. Water is not a problem for an aquatic organism.
Humans and other mammals can’t use this same mechanism. We would have to essentially spend our lives drinking water and urinating to flush the toxic ammonia from our bodies.
To solve this problem, we convert ammonia to a substance called urea. Urea is toxic only in very high concentrations and can be dissolved in water. So, the problem is solved for mammals. By converting ammonia to urea, our kidneys can concentrate the urea and get rid of it with a moderate amount of water.
This method of removal of nitrogen waste does not work for birds. Many of the avian adaptations for flight involve making the body as light as possible. If birds produced urea, they would have to carry around an unacceptably heavy load of water to flush the urea from their body.
Instead, birds convert their ammonia wastes to a compound called uric acid. It takes more energy to convert ammonia to uric acid than to urea. However, the cost is worth it for birds because uric acid is non-toxic and also does not dissolve in water.
Birds therefore get rid of their nitrogen waste by using only enough water to push the paste-like uric acid down the excretory system. The white center in bird guano is uric acid. Last weekend Jurassic Park I, II and III were on TV. The digital dinosaurs were fabulously done... but WAY too drab. I'm sure sexual selection, as in birds, would have resulted in wild variations. <===Note: These are Barney colors
Last edited by NoCoPilot on Sat Jul 10, 2021 2:38 pm; edited 3 times in total |
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richard09
Posts : 4227 Join date : 2013-01-16
| Subject: Re: Dinosaurs With Feathers Sat Jul 10, 2021 2:20 pm | |
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NoCoPilot
Posts : 20163 Join date : 2013-01-16 Age : 69 Location : Seattle
| Subject: Re: Dinosaurs With Feathers Mon Dec 19, 2022 2:54 pm | |
| Dinosaurs made sounds. Lots of them.This article is cutting edge, showing colorful dinos. Bravo. |
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NoCoPilot
Posts : 20163 Join date : 2013-01-16 Age : 69 Location : Seattle
| Subject: Re: Dinosaurs With Feathers Wed Mar 15, 2023 2:28 pm | |
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