There was actually an unauthorized third-party CD-ROM drive for it, the Bung Doctor V64[1]. It didn't actually expand the available ROM space beyond what was possible with cartidges, but its still interesting in that it was allegedly used by licensed Nintendo devs as a lower-cost alternative to the devkits officially provided to them.

[1] https://en.wikipedia.org/wiki/Doctor_V64

not allegedly, iirc the turok devs used one