prefix, employed as combining form of Gr. ἠώς dawn, in scientific terms of recent origin, chiefly Geol. and Palæont. First used in EOCENE, with the sense ‘characterized by the “dawn” or faintly recognizable beginnings of’ (the recent fauna and fora); subsequently, with similar notion, in Eophytic a. [+ Gr. φυτόν plant + -IC], characterized by the earliest appearance of plant-life. Eozoic a. [+ Gr. ζῷον animal], characterized by the earliest appearance of animal life; said of the Laurentian strata and the period represented by them. Also in mod.L. names of fossil genera, believed to be the earliest representatives of types still existing, as Eohippus [+ Gr. ἴππος horse], the oldest known genus of the horse family. Eopteris [+ Gr. πτερίς fern], a genus including the oldest known fern. Eosaurus, the oldest known genus of saurians. Eozoon [+ Gr. ζῷον animal], a supposed genus of foraminifers or rhizopods, at one time regarded as the earliest known animal; its alleged remains are now believed to be of inorganic origin; hence Eozoonal a., pertaining to the eozoon.
1879. Le Conte, Elem. Geol., 504. *Eohippus..., a small animal no bigger than a fox, having three toes on the hind-foot, and four perfect ones on the fore-foot.
1880. Huxley, in Times, 25 Dec., 4/1. I do not see … any reason to doubt that the eocene equidæ were preceded by mesozoic forms, which differed from eohippus in the same way as eohippus differs from equus.
1873. Dawson, Earth & Man, ii. 32. An *Eophytic period preceding the Eozoic.
1879. Le Conte, Elem. Geol., 404. Unless we except the *Eosaurus, these are the first true reptiles found.
1873. Dawson, Earth & Man, ii. 18. *‘Eozoic,’ or those [rocks] that afford the traces of the earliest known living beings.
1871. Hunt, in Proc. Amer. Assoc. Sci., 53. Subsequently to the eozoic times, silicated rocks … are comparatively rare.
1872. Darwin, Orig. Spec., x. 287. The existence of the *Eozoon in the Laurentian formation of Canada is generally admitted.
1879. Le Conte, Elem. Geol., 275. A section of an Eozoönal mass.
1881. R. Etheridge, in Jrnl. Geol. Soc., XXXVIII. 54. The prevalent limestones, Eozoonal or otherwise.
