By Charles Nye on @ad-0rca-ble
Name: Spinosaurus aegyptiacus
Name Meaning: Egyptian Spine Lizard
Classification: Dinosauria, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Megalosauroidea, Megalosauria, Spinosauridae, Spinosaurinae
Spinosaurus is a fairly famous, but mysterious, genus of dinosaur from the Bahariya Formation of Egypt, as well as the Kem Kem beds of Morocco, though other locations may have been home to this genus in Northern Africa. It lived about 112 to 97 million years ago, in the Albian to Cenomanian ages of the Early to Late Cretaceous, and it was possibly the largest known theropod, depending on the metric of “largeness” you’re using. It’s size, however, is not what makes this animal fascinating: rather, it is the only known non-avian dinosaurs to have adapted for a semi-aquatic lifestyle. Much of its traits, according to the most recent research, are convergent with other semi-aquatic animals; leading to many speculative evolution projects on this animal evolving for a fully aquatic lifestyle (much like a whale). It never did, but that does not change the strangeness of this genus on the whole.
It’s size is under some debate, but recent research seems to suggest that it could reach lengths up to 15 meters long, though it would not have been as bulky as Tyrannosaurus, and possibly even lighter than Carcharodontosaurus, though estimates of size and length are still questionable. It had a long, narrow snout, very similar to that of a crocodile, though that similarity is entirely convergent, as the two are nowhere near closely related. It’s skull wasn’t very built for dealing with large land animals; that plus it’s semi aquatic lifestyle indicates that it’s main prey organism was fish. This was probably an instance of extreme niche partitioning, as it lived alongside the large carnivore Carcharodontosaurus, and probably would have yielded most of the land-based prey to it’s Carnosaur neighbor.
By Joschua Knüppe, CC BY 4.0
It had extremely tall neural spines on the back vertebrae, which is mostly hypothesized to have supported a sail structure; they somewhat increased in size from front to back, unlike animals such as Dimetrodon and Edaphosaurus where it was largest in the middle; in addition, there may have been a dip in the middle; furthermore, though Dimetrodon and Edaphosaurus also may have had sails, the neural spines of Spinosaurus were much more flat, unlike the thin rods seen in those synapsids. It’s sail was also unlike Ouranosaurus, which had even thicker spines. Side note: Spinosaurus and Ouranosaurus were not contemporaneous. Though they’re from similar regions, Ouranosaurus is somewhat older. The sailed animal Spinosaurus lived alongside was actually Rebbachisasurus.
The sail may have actually been a hump, however; the spines being similar to extinct hump-backed mammals like Megacerops and Bison latifrons, rather than the known sails of Dimetrodon and Edaphosaurus, though this is under considerable debate. What the sail or hump could have been used for is also under debate, though I consider it unlikely that it was used for thermoregulation. It may have, rather, been hydrodynamic, like that of a sailfish; helping it to swim more efficiently through the water and counterbalance the movements of its neck and tail while swimming. It also had a very long tail, like that of a thresher shark, which may have allowed it to stun fish by slapping it. The sail would also have made it appear larger to shoals of fish, helping to round up fish to eat. The sail also could have been used in display between members of the species.
By José Carlos Cortés on @quetzalcuetzpalin-art
The posture of Spinosaurus is a hot topic of debate at the time of me writing this entry, and more fossils are required to determine how it may have stood, however, it is very unlikely that it was quadrupedal, given that it could not pronate it’s hands. It may have crouched, however, like a pangolin. Whether or not it had feather or pre-feather integument is completely, utterly unknown; though phylogenetically it’s possible, it seems unlikely that they would have been helpful in swimming, so debate is still out, and probably will be unless a miraculous fossil of it’s skin is found (so I have provided both feathered and non-feathered reconstructions in this article). It lived alongside many other dinosaurs in both of the main environments it is known from; in the Kem Kem beds it lived alongside such dinosaurs as Sigilmassasaurus, Sauroniops, Rebbachisaurus, Inosaurus, Deltadromeus, and Carcharodontosaurus; in the Bahariya Formation, it lived alongside such dinosaurs as Aegyptosaurus, Paralititan, Bahariasaurus, and Carcharodontosaurus.
https://en.wikipedia.org/wiki/Spinosaurus
https://en.wikipedia.org/wiki/Kem_Kem_Beds
https://en.wikipedia.org/wiki/Bahariya_Formation
Shout out goes to my lovely boyfriend @plokool; as this is his absolute favorite species of dinosaur <3
pixelskylines
annaxmalina
blakekathryn
jacobvanloon
kaledo-art
snowghoul
gummygunk
dededos
