The process of unrolling is analytical, but the unrolled area can be measured by methods not applicable to other surfaces.
In his history of the Arietidae Hyatt points out that toward the close of the Cretaceous this entire group of ammonites appears to have been affected with some malady; the unrolled forms multiply, the septa are simplified, the ornamentation becomes heavy, thick, and finally disappears in the adult; the entire group ends by dying out and leaving no descendants.
She unrolled her pants legs and slipped into her shoes, giving him a chagrined smile.
The roll of twine was getting small, and it was a nuisance to hold the spool while trying to turn pages, so she unrolled the rest of the twine and tied the end around her waist.
In Terebratulina, Rhyn- chonella, Lingula, and possibly other genera, the arms can be unrolled and protruded from the opened shell; in this case the tentacles also FIG.
