Palæont. [ad. mod.L. Eurypteridæ pl., f. Eurypterus name of the typical genus, f. Gr. εὐρύ-ς broad + πτερόν feather, wing.]
One of a group of fossil Crustacea, abundant in the Silurian and Devonian periods, some of which attained a large size. The name is due to a pair of broad swimming appendages, the hindmost of a series attached to the cephalo-thorax.
1871. Hartwig, Subterr. W., ii. 125. Contemporaneous with the Trilobites were the Eurypterids, which vary from one foot to five or six feet in length.
1873. Dawson, Earth & Man, iv. 71. Eurypterids … with powerful limbs, long flexible bodies, and great eyes in the front of the head.
