sea turtle 3d model

Realistic 3D model of Archelon, the largest extinct marine turtle, based on the provided illustration. Single coherent animal with a massive flattened shell, broad paddle-like flippers, and a streamlined prehistoric body. Rough, leathery skin texture with subtle scale detail, and a slightly weathered shell surface. Use muted gray-blue tones with pale yellow speckling as seen in the reference. Avoid smooth or stylized materials; focus on natural prehistoric marine realism.