[tiffanyg]

It used to happen much more in the past. Many decades ago, AFAIK, at least in the journals / fields / areas I'm familiar with.

I'm not sure where that might happen or be tolerated, today. If you go back and look at research into antibiotics, DNA, etc. back in the 1940s and 1950s ... and even research in the 1960s and 1970s, decades later, there ended up being serious questions around ethics, authorship, etc. for some really seminal papers, for example.