Academic Reading 12

Spinosaurus and Semi-Aquatic Adaptation

Spinosaurus differs from many other large theropods in both skeletal structure and ecological interpretation. Fossil discoveries from North Africa reveal elongated jaws, conical teeth, and dense limb bones. These features have led researchers to reconsider earlier assumptions that large predatory dinosaurs were strictly land-based hunters.

The elongated snout resembles that of modern crocodilians, suggesting specialization for capturing aquatic prey. Conical teeth lack the serrations typical of terrestrial predators, indicating a feeding strategy focused on fish rather than large land animals. Bone density studies further show unusually compact limb bones, a characteristic often associated with animals that spend significant time in water.

Interpretations of Spinosaurus have shifted over time. Earlier reconstructions depicted it as a conventional bipedal predator. More recent findings propose that it may have used its tail for propulsion while swimming. However, complete skeletons remain rare, and some anatomical reconstructions are debated.

Because fossil evidence is fragmentary, paleontologists rely on comparative anatomy, biomechanical modeling, and sediment analysis to evaluate habitat use. Spinosaurus therefore represents an example of how new discoveries can transform understanding of dinosaur ecology, challenging traditional classifications of predatory behavior.

(2) According to the passage, what do dense limb bones indicate?

(3) Why are Spinosaurus reconstructions debated?

(4) What can be inferred about interpretations of Spinosaurus?

(5) The word “propulsion” in the passage is closest in meaning to