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 :)
John Locke In the pursuit of an argument there is hardly room to digress into a particular definition as often as a man varies the signification of any term. 1959, Tom Lehrer (music), âIn Old Mexicoâ: [â¦] For I hadn't had so much fun since the day / my brother's dog Rover / got run over. / (Rover was killed by a Pontiac. And it was done with such grace and artistry that the witnesses awarded the driver both ears and the tail â but I digress.)