The Miocene was the first epoch of the Neogene period (23-2.5 million years ago), followed by the much shorter Pliocene epoch (5-2.6 million years ago); both the Neogene and Miocene are themselves subdivisions of the Cenozoic Era (65 million years ago to the present). Climate and geography.
The dictionary meaning of the word Digress is 'to leave the main subject temporarily in speech or writing.' or simply deviate. As you say,I digress means  I am straying from the main subject right now. . Like in this sentence - 'I need to digress a bit to let the ink dry.'. Hope this helps :)
vb, digs, digging or dug. 1. (when: tr, often foll by up) to cut into, break up, and turn over or remove (earth, soil, etc), esp with a spade. 2. to form or excavate (a hole, tunnel, passage, etc) by digging, usually with an implement or (of animals) with feet, claws, etc: to dig a tunnel. 3. (often foll by through) to make or force (one's way), esp by removing obstructions: he dug his way through the crowd. 4. (tr; often foll by out or up) to obtain by digging: to dig potatoes; to dig up treasure. 5. (tr; often foll by out or up) to find or discover by effort or searching: to dig out unexpected facts.