Question ID:PT22 S4 Q22 Passage:Dinosaur expert:  Some paleontologists have claimed that birds are descendants of a group of dinosaurs called dromeosaurs. They appeal to the fossil record, which indicates that dromeosaurs have characteristics more similar to birds than do most dinosaurs. But there is a fatal flaw in their argument; the earliest bird fossils that have been discovered date back tens of millions of years farther than the oldest known dromeosaur fossils. Thus the paleontologists' claim is false. Stem:The expert's argument depends on assuming which one of the following? Correct Answer Choice:DChoice A:Having similar characteristics is not a sign that types of animals are evolutionarily related. Choice B:Dromeosaurs and birds could have common ancestors. Choice C:Knowledge of dromeosaur fossils and the earliest bird fossils is complete. Choice D:Known fossils indicate the relative dates of origin of birds and dromeosaurs. Choice E:Dromeosaurs are dissimilar to birds in many significant ways.