Transitions which introduce a new idea are called additive transitions.
Additive is the adjective form of the noun addition, which comes from Latin additio: addere (add) + the suffix -tio (the act of).
By using additive tansitions, you can either put in new elements which strenghten, specify, or continue your argument, or you can present entirely new ideas.
Examples include:
- similarly or likewise to introduce a comparable element;
- what's more, besides, in addition, moreover, or furthermore to introduce a different piece of information going in the same direction as your point;
- namely or specifically to introduce a precision regarding something you've already stated.