Mosasaur tail morphology reveals burst swimming performance and ecological diversity.

Mosasaur tail morphology indicates russellosaurines achieved higher burst swimming speeds than mosasaurines, revealing distinct predatory strategies in Late Cretaceous oceans.

• Why it matters: Understanding extinct animals' locomotor performance is crucial for reconstructing their ecological roles, but soft tissue data is rarely preserved, limiting direct insights into their movement capabilities.
• What they did: The study used a drag-based "slam-start" biomechanical model, analyzing skeletal and muscle reconstructions from four mosasaurs to estimate lunge velocities across various parameters.
• The result: Findings show tail morphology significantly influences burst speed, with russellosaurines being faster ambush predators, demonstrating how physics-based models can infer extinct animals' performance from fossilized features.