In 1860 Bavarian quarry workers discovered the impression of a feather in a limestone slab dating to the Mesozoic era. It had previously been assumed that birds developed only after the close of the Mesozoic era and after the disappearance of pterosaurs, a species characteristic of that era. But there in limestone lay the imprint of a fully aerodynamic, three-inch-long feather. This, therefore, must have been the earliest bird-certainly the earliest found to the date.
The argument assumes which one of the following?
(A) The creature to which the feather belonged was a descendant of the pterosaurs.
(B) Birds with such feathers were preceded by species of birds with less-developed feathers.
(C) In the Mesozoic era, no creatures other than birds had such feathers.
(D) The feather belonged to a Mesozoic creature that was neither a pterosaur nor a bird, but intermediate between them.
(E) The earliest bird flew in an awkward manner.
OA: Later
The argument assumes which one of the following?
(A) The creature to which the feather belonged was a descendant of the pterosaurs.
(B) Birds with such feathers were preceded by species of birds with less-developed feathers.
(C) In the Mesozoic era, no creatures other than birds had such feathers.
(D) The feather belonged to a Mesozoic creature that was neither a pterosaur nor a bird, but intermediate between them.
(E) The earliest bird flew in an awkward manner.
OA: Later
