Spinosaurus ("thorn lizard") is the name of a genus of dinosaurs of the Late Cretaceous era (95 million years ago), noted for their blade-like neural spines (extending 1.7 meters), presumably covered with a sail-like skin.

In 1912, Ernst Stromer von Reichenbach was searching for fossils with Richard Markgraf near the Bahariya Oasis in Egypt. He found a lower jaw, part of the maxilla, several vertebrae, and a pubic bone of this large theropod. In 1915, he published his findings, naming the animal Spinosaurus aegyptiacus, "thorn lizard of Egypt" for its distinguishing feature: dorsal spines extending nearly 2 meters.

The holotype of Spinosaurus aegyptiacus was incomplete to begin with, and removing it in situ caused some damage. Complications in the political climate meant Stromer had to wait until 1922 to bring his fossils to Germany, and they were further damaged in shipping. The fossils were housed at the Bayerische Staatssammlung museum in Munich. When World War II came, and other museums were shuffling their collections off to safe havens, the head of the museum, a fervent supporter of the Nazi party, refused Stromer's request to move them to safety. So when the RAF bombed Munich on April 24, 1944, the only known remains of Spinosaurus were destroyed. Only Stromer's monographs survived.

Much of the thinking of what Spinosaurus was like, then, comes from later findings of different species within the same family, notably more complete specimens of Baryonyx walkeri and Suchomimus tenerensis. The teeth in all these spinosaurids are conical and unserrated. The jaws are slender and narrow. A secondary palate and other skull features are analagous to the "snatch and grab" hunting allowed by crocodilian anatomy. And taking into account the geography and climate of the Bahariya area of the time (swampy), it was likely a fish-eater.

So why did Spinosaurus get equal billing opposite America's sweetheart, Tyrannosaurus rex, in the motion picture Jurassic Park III?

Three reasons:

  1. The vertebra described were larger than T. rex's.
  2. Analysis of the bones suggested the holotype specimen was a juvenile.
  3. Extrapolating from the size of the jaw, the creature may have reached 45-50 feet in length, making it the longest theropod.
So if you're making a movie about dinosaurs, and you ask paleontologist Jack Horner, you hear of anything cool-looking that was bigger than T. rex, and he says, "Well, this spinosaurus thing--"

In 1996, another species, Spinosaurus maroccanus, was described, although this find in Morocco could conceivably be a juvenile version of the Egyptian variety. Paul Sereno and colleagues noted:

"Although the Moroccan and Algerian materials have been referred to a different species (S. maroccanus), its distinction from S. aegyptiacus (by the proportions of the centrum of an isolated cervical vertebra) and the basis for the referral of additional material are questionable. We regard S. maroccanus as a nomen dubium and provisionally refer all spinosaur material from Albian- and Cenomanian-age rocks in northern Africa to S. aegyptiacus."

Classification: Archosauria: Saurischia: Theropoda: Tetanura: Spinosauria: Spinosaurus

Cf. these other spinosaurids:

Jeananda Col. "Paleontologists." ZoomDinosaurs.com. <http://www.enchantedlearning.com/subjects/dinosaurs/glossary/Paleontologists.shtml> (16 April 2004)
Jaime A. Headden, "Dinosauria: Theropoda: Spinosauroidea - Spinosaurs Are Tetanurans, Too." Qilong Web site. <http://members.tripod.com/~Qilong/Spinosaurs/spino.html> (14 April 2004)
Thomas R. Holtz, Jr. "Spinosaurs as Crocodile Mimics." Science. Vol. 282, Issue 5392, 1276-1277. 13 Novbember 1999. <http://www.sciencemag.org/cgi/content/full/282/5392/1276> (16 April 2004)
Matthew C. Lamanna. "Bahariya Dinosaur Project." Matthew C. Lammana Home Page. 14 February 2003. <http://www.sas.upenn.edu/~lamanna/egypt.html> (16 April 2004)
Mickey Mortimer, "Re: armoured spinosaurs." <dinosaru@usc.edu> 5 January 2002. Leslie T. Reissner. Review of The Lost Dinosaurs of Egypt, by William Northdrupt and Joshua Smith. Amazon.com 8 January 2003. <http://www.amazon.com/exec/obidos/ASIN/0375507957/ref=ase_egyptdinos-20/103-2787661-3713429> (14 April 2004)
Michon Scott. "Rocky Road: Ernst Stromer." 7 June 2003. <http://www.strangescience.net/stromer.htm> (16 April 2004)
Paul C. Sereno, et al. "A Long-Snouted Predatory Dinosaur from Africa and the Evolution of Spinosaurids " Science, Vol 282, Issue 5392, 1298-1302 , 13 November 1998. <http://www.sciencemag.org/cgi/content/full/282/5392/1298> (16 April 2004)