Question

Until the late twentieth century, all groups of dinosaurs were believed to be extinct. However, the fossil record indicates that birds are the modern descendants of feathered dinosaurs. They have evolved from theropod ancestors during the Jurassic Period.
Choose the option that best combines the sentences at the underlined point. [Advanced]

• A. Until the late twentieth century, all groups of dinosaurs were believed to be extinct but the fossil record indicates that birds are the modern descendants of feathered dinosaurs; they have evolved from theropod ancestors during the Jurassic Period.
• B. While until the late twentieth century, all groups of dinosaurs were believed to be extinct, however, the fossil record indicates that birds are the modern descendants of feathered dinosaurs; they have evolved from theropod ancestors during the Jurassic Period.
• C. Although all groups of dinosaurs were believed to be extinct until the late twentieth century, the fossil record indicates that birds are the modern descendants of feathered dinosaurs, having evolved from theropod ancestors during the Jurassic Period.
• D. NO CHANGE

Answer 1

Answer: (C)

Although all groups of dinosaurs were believed to be extinct until the late twentieth century, the fossil record indicates that birds are the modern descendants of feathered dinosaurs, having evolved from theropod ancestors during the Jurassic Period.

To form adversative compound sentences, adversative conjunctions like "although" must be used to express the contradiction between two main sentences. Hence, Option C is correct. The rest of the options use conditional conjunctions and do not bring out the contrast, hence incorrect.