Carnivorous dinosaurs other than the famous t-rex and spinosaurus..

[johnny rex]

(09-24-2020, 03:23 PM)DinoFan83 Wrote:

(09-24-2020, 01:18 PM)johnny rex Wrote:

(09-24-2020, 08:12 AM)DinoFan83 Wrote: Here is some food for thought on Megalosaurus: It would appear that judging by the proportions of relatives, this animal is a lot less 'vanilla' than many of us think.

Going by GetAwayTrike's skeletal, this is a fairly large skulled animal - for the largest specimen (BMNH R1101, an 83.2 cm ilium), a 115 cm long skull on an animal that appears to be close to 2 tonnes based on eyeballing with many volumetric estimates. Since all known cranial material was found in isolation and it is not known what size Megalosaurus it belongs to, the skull was apparently cross scaled from his Torvosaurus using the ratio of a postcranial element to skull size, but I don't know exactly what he had done as from what I can see, Torvosaurus' proportions result in larger skulls than how he depicted, even if it is fairly large already. 
For example, using pubis length to scale. According to the Theropod Database, the pubis of the Torvosaurus holotype is 73.6 cm long compared to a 115 cm skull following GAT's skeletal. Using the scalebar in GAT's Megalosaurus, the pubis length ends up at about 89.9 cm, thus a skull length of 140.4 cm using the pubis to skull ratio of Torvosaurus as opposed to 115. 

Another thing is the forearms - as with the cranial material, the forearm material for Megalosaurus has been found isolated and it's not given that it was from an animal similarly sized to BMNH R1101, even though GAT composited it into the largest individual unlike what he did with the skull.
Therefore, a megalosaur that preserves very complete arm material and associated postcrania (Afrovenator) is a good choice to scale from. Following the Theropod Database, the Afrovenator holotype had a 40 cm humerus compared to a 57 cm ilium, which would result in a 58.4 cm long humerus for BMNH R1101.

To put all that into perspective, this is what such an animal would have looked like. I unfortunately cannot yet articulate these images in GIMP yet but on the left and center is what the head and body would look like following the above scaling (by GetAwayTrike), and on the right is the forearm size (from Scott Hartman) that this animal would have had with the cross scaling.

*This image is copyright of its original author

These in my opinion make for a set of proportions reminiscent of a big game hunter that needs as much weaponry as possible with which to bring down large prey. Provided the cross scaling is roughly accurate, it would have had an IMMENSE head and very lethal bite, but also quite large, robust, usable, and damaging forelimbs. No other carnivorous dinosaur in this weight class that I am aware of would have had this combination of such a big head together with big arms.

Do you have any idea about the skull width of Megalosaurus?

I would expect something similar to tyrannosaurids for the most part, but without the super wide rear portion. This is what that looks like, credit to GAT for the Megalosaurus skull and dorsal view is modified from theropod1's Tyrannosaurus skull.

*This image is copyright of its original author

Edit: here's some food for thought for anyone reading this post. With the adjusted arms and head, I would expect the Megalosaurus to be about 2.2 tonnes. Following the data from Benson (2014) supplementary material (38.8 cm humerus, 19.1 cm circumference), and the supplementary data from Campione and Evans 2012 (a 434 kg grizzly bear with a 14.6 cm circumference humerus), this means that this cross scaled Megalosaurus would have had arms proportionally more robust than a grizzly (and they are known for being robust for a bear) by 17.7 percent.

If Megalodon have similar bizygomatic to Torvosaurus, with skull length around 115 cm and more I think the skull width will be around 40 cm or a little bit more. I just saw a picture of a Torvosaurus skull from the front view by using Google search engine so I imagine the skull width is something around 40 cm or a little bit more. 

I believe Megalosaurids, coupled with huge skulls and large clawed arms, are formidable predators. I imagine if they live alongside the prehistoric mammalian predators, such as the prehistoric bears and big cats, the Megalosaurids will tend to dominate them especially over preys or direct confrontations. Reply