Another serif sub-types are the Transitional serif fonts. They date back to the 18th century and they are of course the bridge between Humanist and Old Style serif fonts to Modern typefaces. One of their features is that they have much more contrast between thick and thin strokes, also they have a more vertical axis.
A good example of a more recent transitional serif is Times New Roman. It was drawned in 1931 by Victor Lardent with the supervision of Stanley Morison as a commission for the British newspaper, “The Times”.
Some characters in transitional serif typefaces feature a slightly more open shape, which helps increase legibility, something very very valuable for a newspaper typeface, don’t you think?