Everything Science Forum

Apatosaurus browsed the tops of trees, on riverbanks. Scientists believe that these sauropods could not raise their necks to an angle of 90 degrees, as doing so would slow blood flow to the brain excessively; blood starting at the body proper would take two or more minutes to reach the brain. Furthermore, studies of the structure of the neck vertebrae have revealed that the neck was not as flexible as previously thought.
-source: http://en.wikipedia.org/wiki/Apatosaurus

I've been looking at their teeth, their necks, their enormous size, their nostrils... And I have trouble seeing them spending much time on land. Perhaps they dined on seafood.

• Their teeth don't look like they're suited well for vegetation. What would it be like trying to get plant matter down that long road? Stripping leaves off trees with those teeth seems like trying to cut hair with a comb. However they could've done it, wouldn't that have demanded considerable effort?
• From the Wikipedia entry above, getting their heads up high would've been uncomfortable to say the least.
• How much protein can they get from an herbivorous diet compared to one with fish as a staple? And wouldn't that be an easier ride down their throats? Looking at giraffes, they like to chew it up first. I guess as herbivores, sauropods would've needed a gizzard with stones, and a moist throat.
• I see some nostrils are over their eyes. A dino-snorkel?

Maybe the extended neck length assisted some kind of fishing tactic(s). And living around the water most of their time means good support for their weight (especially their necks), an escape from the massive hunters like Spinosaurus... I can see them sunning like walruses. If their fossils are found along river banks, then that can support the theory.

What do you think? Could sauropods have been predominately semi-aquatic?

I'd be surprised if Apatosaurus wasn't semi-aquatic.  Some of the leading theories do suggest that sauropods were aquatic, most probably swamp or lake-dwelling, where they could keep their long necks under water for most of the time.

http://dino.lm.com/images/display.php?id=3456
http://www.dinodata.org/index.php?option=com_content&task=view&id=5955&Itemid=67
(You'll need to register to see that last link)

The interesting thing about Apatosaurus right now is that the multitude of genera are being re-analyzed, and the hundreds of genera previously recognized have been norrowed down to only four valid species. 

We obviously still have a lot to learn about these long-necked beasts.