Phantasy Star Online Ep 1&2 Xbox has a Gamecube texture set prs compressed in the default.xbe. Jpn messages about the GC disc door open and such.

dvd/map_jungle01_00n.rel seems to be Dreamcast format. Closer to Jungle 3 as well.

...n.rel is the level mesh data.

Textures matches map_jungle03(Mericarol miniboss area).

map_jungle03_00n.rel
GC: 1.55 MB
Xbox: 1.53 MB

The Most likely Dreamcast version is 1.17 MB.

Bone count
DC: 775
GC/Xbox: 774