Unit 2: Evolution: 2.1.2A Mister Big

Ibrahim’s dreams were inextricably entangled with those of another paleontologist who had ventured into the desert a century earlier.

Ibrahim’s dreams were inextricably entangled with those of another paleontologist who had ventured into the desert a century earlier.

Despite illness, desert hardships, and the gathering upheaval of World War I, Stromer found some 45 different taxa of dinosaurs, crocodiles, turtles, and fish.

Its most extraordinary feature, however, was the six-foot sail-like structure that it sported on its back, supported by distinctive struts, or spines.

Stromer’s discoveries, prominently displayed in the Bavarian State Collection for Paleontology and Geology in central Munich, made him famous.

But the museum director, an ardent Nazi who disliked Stromer for his outspoken criticism of the Nazi regime, refused.

But the museum director, an ardent Nazi who disliked Stromer for his outspoken criticism of the Nazi regime, refused.

While most doctoral students explore a tightly circumscribed topic, Ibrahim’s 836-page dissertation at University College Dublin described the entire fossil record of the Kem Kem.

While most doctoral students explore a tightly circumscribed topic, Ibrahim’s 836-page dissertation at University College Dublin described the entire fossil record of the Kem Kem.

On a visit in 2008, when Ibrahim was 26, a local nomad showed him a cardboard box containing four blocks of distinctive purplish stone streaked with yellow sediment.

On a visit in 2008, when Ibrahim was 26, a local nomad showed him a cardboard box containing four blocks of distinctive purplish stone streaked with yellow sediment.

Like all fossils heedlessly torn from their surrounding geology, the bones’ scientific value was dubious.

The specimen was laid out on tables in the basement: leg bones, ribs, numerous vertebrae, and several tall, distinctive dorsal spines.

Dal Sasso and Maganuco told him that the dealer thought it had been excavated at a site called Aferdou N’Chaft, near El Begaa in Morocco.

After driving their battered Land Rover through the palm plantation north of Erfoud, the man led them on foot along a dry riverbed and up a steep bluff.

Visible rock layers in the surrounding cliffs showed that great meandering rivers had flowed there a hundred million years ago.

For Ernst Stromer, Spinosaurus was a lifelong enigma.

He first speculated that its long dorsal spines (which protrude from the back) might have supported a shoulder hump like a bison’s, then later surmised that they were part of a brightly colored dorsal sail possibly used for communication, like those sported by some modern lizards and chameleons.

He first speculated that its long dorsal spines (which protrude from the back) might have supported a shoulder hump like a bison’s, then later surmised that they were part of a brightly colored dorsal sail possibly used for communication, like those sported by some modern lizards and chameleons.

So were its teeth—most carnivorous theropods had bladelike, serrated teeth, but these were smooth and cone-shaped, and resembled those of a crocodile.

Other scientists have suggested the paradox is merely sampling error, caused by geological processes that mix fossils of different ages together—or by fossil hunters who preferentially select large, spectacular carnivores because they sell better.

The spines had few channels for blood vessels, so it seemed unlikely that they were used to regulate body temperature, as other researchers had conjectured.

The forelimbs and thoracic girdle were bulky, while the hind limbs were disproportionately short and slender.

By painstakingly shaping and spacing the 83 vertebrae in their model, they determined that an adult Spinosaurus measured 50 feet from nose to tail.

All this came home to Ibrahim with full force when he saw the culminating phase of the digital dinosaur project: a life-size Spinosaurus skeleton in high-density polystyrene foam, created from the computer model in part by a 3-D printer.