What? How could it predate telnet? That was RFC 15 from freakin' 1969 and before that, there isn't really anything. But even if you consider RFC 854 to be telnet, well that's https://tools.ietf.org/html/rfc854 May 1983, rlogin was released in 4.2BSD, that's July 1983 http://www.informatica.co.cr/bsd/research/acrobat/830721.pdf

Well they may not have technically predated then but what I meant is that as far as I know for a while r(etc) was used and then was generally replaced in actual usage by telnet, etc.

It was the other way around. Rsh and rlogin appeared well after telnet, and displaced some telnet use because they were able to do password-free connections via .rhosts

Oh yes that file. The good old days when you would use social engineering on irc to have yourself added to your victim's .rhosts