My new Spinosaurus aegyptiacus: based on the recent exciting discovery by Nizar Ibrahim and Paul Sereno that turned all scientific understanding about this creature upside down.
The most unusual and arguably important part of this discovery was the unusually small pelvis and hind limbs relative to the size of the other parts of this creature, with broad, flat claws and feet (usually occurs in webbed-foot animals)- indicating that Spinosaurus was in fact the first dinosaur ever known to be aquatic (and also likely the first known quadrupedal theropod). Such a lifestyle had strong evidence from previous fossil records (including remains of various fish in its stomach, previously discovered crocodile-esqe jaws, and the fact these fossils keep appearing in areas with abundant ocean life, but not-quite as frequent terrestrial lifeforms). However, no evidence it was actually a swimmer appeared until this discovery- forcing scientists beforehand to presume that if it had consistent body proportions to other theropods, it would have behaved like a stork.
In this image, rather than conforming to an estimated scale, I instead based the image precisely off the computerized anatomical reconstruction displayed with the study, and then scaled up to approximately match the specific scale of:
The length of entire head (estimated to be roughly the same length as a man)- here shown at exactly 1.7m
The longest spine bone at 7 feet long (at a slant).
The overall length of the creature depicted here is almost 16m long- which roughly matches the length estimated in the study.
Note, the length of the legs is based directly off the original scale presented by Dr Ibrahim. Some debate had arisen when professional skeletal reconstruction expert Scott Hartman raised an issue with the depicted scale of the legs and pelvis in the computer-generated image compared to the numerical measurements stated in the study; rescaling the legs and pelvis to match. Dr Ibrahim replied that this was the scale generated by the computer itself based on CT scans of the bones, and the appearance of being shorter is partly due to the angles of the bones viewed from a 2D perspective. In this image, I simply decided to err towards the original CT scan.
That aside, in fleshing-out the animal I depicted a fairly thick layer of muscle, fat and skin, leaving a streamlined animal. The sail on its back is shown smooth and wrapped in muscles (rather than bony with a membrane: makes more sense that its back muscles spanned the entire spine, especially if it was an active swimmer- my guess is that the spine simply acted like a fin- like a shark or dolphin). In my opinion, the tail may very likely have had additional elongated tissue or possibly even dorsal spines to act as a paddle- BUT I have decided to omit any stylish touches until any evidence comes to light (so far scientists have very few tail vertebrae- and are forced to, once again, defer to other Spinasauroids- which had rather typical tail bones. The colour is a mix between pied (like Orcas and most sharks) along with black/white banded (sea snakes). Both very typical colours of aquatic life, and perfect for a swimming predator.
Added for good measure is my recently completed Tyrannosaurus to put the Spinosaurus to scale. This animal is shown at precisely 12m long, with a 1.5m long head (about the largest they got).
While other mega-theropods (Giganotosaurus, Maposaurus) have yet to be completed, I would point out that these animals are more-or-less the same size as T-Rex based on extensive measurements by Scott Hartman.