Author order when senior and lead author same person I have an article I'm writing where I'm the senior author, but I also did the majority of the work and wrote the paper. I have two co-authors who have also contributed.

In my field (physical sciences) the norm is that the senior author goes last and the person who wrote the paper/did the majority of the work is first author. Everyone else goes in between. 

What should the order should be in this situation when lead and senior author are same person?
I've been in a similar situation as a co-author in a paper where the corresponding and the senior author are the same. In this case, this author listed herself as the first author (since she made most of the work and wrote the paper) and the remaining co-authors were listed alphabetically. An important detail is that some journals allow or even require that you specify the contributions of each author.