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 :)
Synonyms and Antonyms of digression a departure from the subject under consideration the professor's frequent and extended digressions are the stuff of campus legend Synonyms of digression aside, tangent, divagation, excursion Words Related to digression excursus, parenthesis; rambling; circuitousness, circularity, circumlocution, diffuseness, prolixity, verbosity, windiness, wordiness