Spinosaurus

Did Spinosaurus dive into water to seek its prey or lay in wait by the shore awaiting a meal of opportunity? New findings into Spinosaurus’ habitat have made the prospect of a swimming spinosaur even more intersting.

Paleontologists from the University of Pennslyvania have found clues in Egypt giving information about spinosaurus’ habitat. It is believed that the Bayharia Oasis which was where the orginal spinosaur fossils were found, was once a Mangroove swamp. This swamp would have been similar to the Florida Everglades of today.

Click to enlarge… © Luis Rey

Spinosaurs fed on fish and was probably in the mangroove waters eating coelacanth and sharks. The long narrow snout of Spinosaurus contained jaws full of sharply pointed teeth. Spinosaur teeth were smooth, round, and resembled the bite of crocodiles, where the upper teeth of the Spinosaurus interlock with the lower teeth. In addition, Spinosaurus had nostrils that faced upwards. A very useful adaptation for swimming and hunting fish , much like the nostrils in Crocodilians. Like the American Crocodile, Spinosaurus may have also ventured out into the ocean to catch prey.

There are reports and suggestions that Spinosaurus also fed on juvenile dinosaurs such as pterosaurs and Iguandon, but most agree that its staple food source came from the water.

Many hypothesize that the sail was a means by which to radiate heat, whereas I can envision just the opposite. I picture Spinosaurus silently floating on the surface of a body of water using its forelimbs as a stabilizing mechanism while utilizing its sail as a solar collector maintaining body temperature as it waits for prey.

Click to enlarge… © paleoguy60

Spinosaurus is considered to be carnivorous, more specifically, piscivorous or a piscivore. These conclusions are based upon comparisons of their jaws with that of modern crocodilians.

Click to enlarge… © Todd Marshall

Fossil evidence suggests that Spinosaurus fed on fish as well as a variety of other small to medium-sized animals, including small dinosaurs. Baryonyx, a close relative of Spinosaurus, was found with fish scales and the digested bones of a young Iguanodon in its stomach cavity, and there is one documented example of a spinosaurid having eaten a pterosaur. Much like today’s crocodile, the spinosaur was a generalist and opportunistic feeder specializing in meals comprised of smaller prey of any kind, including fish.

Now, this is where this post gets interesting,… An Internet search of “Spinosaurus” will yield many results entitled, “Spinosaurus, The Largest Carnosaur” which appears to not be true. Carnosaurs - Greek for “meat-eating lizards” - are characterized by several features, mostly modifications of the pelvis and hind legs (possibly adaptations evolved along with their increased size). For example, the carnosaurian femur is larger than the tibia. Also characteristic of the Carnosauria are large orbits and a generally long, narrow skull. Most of the skeletons of the large theropod carnosaurs exhibit different characteristics and builds than that of spinosaurids. This has resulted in many palenotologists removing Spinosaurus from the ranks of Carnosauria.

Click to enlarge… © Maurilio Oliveira

Let’s split some more hairs,… carnivorous is defined as, “subsisting or feeding on animal tissues…” whereas a carnivore is defined as, “any of an order (Carnivora) of typically flesh-eating mammals…”. Spinosaurus was hardly a mammal. This all being said, it is generally accepted that Spinosaurus was the largest of all known carnivorous dinosaurs. Additionally, being that the spinosaur hunted its prey, it is considered to be the largest known predatory dinosaur.