Bavarian quarry workers_LSAT

gmat_perfect wrote: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

gmat_perfect wrote: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

gmat_perfect wrote: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