Final answer:
Neandertals were stockier and had a more robust build than modern humans, with distinctive cranial features like a large brain and pronounced brow ridges. They possessed well-developed musculature suitable for their environment and lived in Europe and parts of Asia before interbreeding with modern humans.
Step-by-step explanation:
Comparison of Neandertal Body Shape to Modern Humans: Neandertals, also classified as Homo neanderthalensis, presented a stocky and barrel-chested physique which significantly differs from the body shape of most modern humans. Their heavy musculature and robust build suggest a good adaptation to their cold environments. Neandertals were short and had a distinctive cranial structure; their skulls were large and rounded at the back, with pronounced brow ridges, a feature reminiscent of Homo erectus. They had an average brain size of around 1,520 cc, larger than the modern human average of 1,200-1,400 cc. However, the implication of a larger brain size in terms of intelligence is unclear since regions of the brain related to cognitive skills may have been organized differently in Neandertals compared to modern humans. In terms of facial structure, Neandertals had large nasal cavities and front teeth with excessive wear, often attributed to the use of their mouths as a tool for tasks such as leatherworking. Their postcranial bones indicate well-developed rotator cuff muscles, and their robust humerus suggests that they were capable of throwing projectiles and using spears. Despite the physical differences, it is important to note that Neandertals interbred with modern humans, and many current humans carry Neandertal DNA markers to this day.