Spinosaurus News ~

[tigerluver]

(01-28-2021, 10:28 PM)DinoFan83 Wrote:

Quote:I feel a caveat with the pneumaticity is that it is not uniform. A pneumatic neck won't help the animal stay much afloat of the rest of the body is dense (which seems to be the case here). At best, the animal will have a floaty head/neck which can reduce the cost of elevating its head above water to breath but the body would still be a sinking rock.

Yes, that's what I was referring to, my bad. The earlier suggestions in the thread were precisely as you have said.

Quote:Looking at these cross-sections, Spinosaurus matches most closely with those that spend a significant time submerged. The hippo for instance is not a fast moving dolphin (however, it can actually be deceptively fast) but spends a significant time in the water. 

Good finding. Let it be known that I do not actually find the assignment of the pneumatic vertebrae likely on the whole, my previous post was operating under a 'assuming that x (assignment of pneumatic vertebrae) and y (new lifestyle) are correct, which they aren't necessarily but it's what will be assumed for the sake of demonstration'.

Quote:Dr. Ibrahim also made a great point to counter the most recent paper in this article, where he states:
"Nobody suggested Spinosaurus was a dolphin-like, lightning-speed predator … You have to look at the prey animals in Spinosaurus's river system, which include enormous coelacanths and other slow-moving aquatic animals... T. rex was not a fast runner, but it was fast enough to pursue a Triceratops or Ankylosaurus, and that's all that matters, folks.”

And from Dr. Pierce:
"To me, the combination of anatomical features indicates strong aquatic adaptations, a semiaquatic animal able to swim in water,” Harvard paleobiologist Stephanie Pierce, a senior author of the 2020 Spinosaurus study, writes in an email. “I don't think it was a pursuit predator as they very narrowly define it in the paper, but an animal that could presumably swim and lunge burst after its prey, catching it in the water column. They are getting swept up in definition."

Modern animals can help us figure out what extinct animals did. However, extinct animal do not have to exactly fall in line with what we see today and could certainly have developed their own unique adaptations.

^This I can agree on. I actually think a relatively slow-moving ambush lunge predator would have a very hard time with any airsacs, given their potential to mess up buoyancy and reveal its presence to its prey.
Now hearing about it, Ibrahim's newest point makes sense IMO. More than the one from Hone and Holtz, actually. 
Because you don't need to be a crocodilian-like swimmer to ambush big and slow moving fish.

What studies are available on determining the average thoracic density? How would the lungs and rest of the viscera affect the density relative to 1 g/ml? Reply