<p>What filter?  Modern vertebrate blood is always red (with just one exception AFAIK: <a href="https://en.wikipedia.org/wiki/Channichthyidae" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Channichthyidae</a> ) because it is based on hemoglobin.  Given that birds, which descend from one branch of the dinosaurs, have red blood, it's likely that the dinosaurs did as well.  Likewise plants are mostly green due to the chlorophyll used for photosynthesis, another thing that would be strongly conserved by evolution.</p>

CC BY-SA 4.0
2020-05-05T18:34:00.593Z
Thank you but does the atmospheric pressure make a difference? Oxygen was different 80 million years ago. How heavy is that pressure today if I would breath 80 million year old oxygen. Would my blood still be red?
Angel Tena
CC BY-SA 4.0
2020-05-06T03:59:59.253Z
@Angel Tena: Humans (and other creatures) are able to adapt to a considerable range of pressure, from the less than 1/2 atmosphere of high mountains to the 2-3 atmospheres of (non-technical) scuba diving.  (And whales &c can dive much deeper.)  Yes, your blood would still be red!
jamesqf
CC BY-SA 4.0
2020-05-05T04:03:45.867Z
2020-05-05T04:03:45.867Z
jamesqf
<p>Was dinosaur blood really red? Was the vegitation really green?Can that filter be used today?</p>

CC BY-SA 4.0
2020-05-05T09:46:05.777Z
Welcome on the Earth Science SE! Your last question is unclear to me, please elaborate.
peterh
<human-influence><oxygen>
Filtered pressured oxygen 80 miilion years ago
Angel Tena
# Filtered pressured oxygen 80 miilion years ago

(Asked by: username_0 on 2020-05-05)

Was dinosaur blood really red? Was the vegitation really green?Can that filter be used today?

**Tags:** human-influence, oxygen

> **Comments:**
> **username_1**: Welcome on the Earth Science SE! Your last question is unclear to me, please elaborate.  

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## 1 answers

### Answer by username_2 on 2020-05-05. Score: 1

What filter? Modern vertebrate blood is always red (with just one exception AFAIK: <https://en.wikipedia.org/wiki/Channichthyidae> ) because it is based on hemoglobin. Given that birds, which descend from one branch of the dinosaurs, have red blood, it's likely that the dinosaurs did as well. Likewise plants are mostly green due to the chlorophyll used for photosynthesis, another thing that would be strongly conserved by evolution.

> **Comments:**
> **username_0**: Thank you but does the atmospheric pressure make a difference? Oxygen was different 80 million years ago. How heavy is that pressure today if I would breath 80 million year old oxygen. Would my blood still be red?  
> **username_2**: @username_0: Humans (and other creatures) are able to adapt to a considerable range of pressure, from the less than 1/2 atmosphere of high mountains to the 2-3 atmospheres of (non-technical) scuba diving.  (And whales &c can dive much deeper.)  Yes, your blood would still be red!  

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