Sentence Examples with the word Hyatt

Alpheus Hyatt (1838-1902) was the first to discover (1866) that these changes in the form of the ammonite shell agreed closely with those which had been passed through in the ancestral history of the ammonites.

Among invertebrates Barrande's doctrine of centres of origin was applied by Hyatt to the genesis of the Arietidae (1889); after studying thousands of individuals from the principal deposits of Europe he decided that the cradles of the various branches of this family were the basins of the CSte d'Or and southern Germany.

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.