Source : Free On-Line Dictionary of Computing

dinosaurs mating
     
         The activity said to occur when yet another {big
        iron} merger or buy-out occurs; reflects a perception by
        hackers that these signal another stage in the long, slow
        dying of the {mainframe} industry.  Also described as
        "elephants mating": lots of noise and action at a high level,
        with an eventual outcome in the somewhat distant future.
     
        In its glory days of the 1960s, it was "{IBM} and the Seven
        Dwarves": {Burroughs}, {Control Data}, {General Electric},
        {Honeywell}, {NCR}, {RCA}, and {Univac}.  Early on, RCA sold
        out to Univac and GE also sold out, and it was "IBM and the
        BUNCH" (an acronym for Burroughs, Univac, NCR, Control Data,
        and Honeywell) for a while.  Honeywell was bought out by Bull.
     
        Univac in turn merged with {Sperry} to form Sperry/Univac,
        which was later merged (although the employees of Sperry
        called it a hostile takeover) with Burroughs to form {Unisys}
        in 1986 (this was when the phrase "dinosaurs mating" was
        coined).  In 1991 {AT&T} absorbed NCR, only to spit it out
        again in 1996.  Unisys bought {Convergent Technologies} in
        1988 and later others.
     
        More such earth-shaking unions of doomed giants seem
        inevitable.
     
        [More dates?]
     
        [{Jargon File}]
     
        (1998-07-10)