Can I use Rare Candy to evolve from Dome Fossil to one of the Kabutops from older expansions that evolve from Mysterious Fossil?
Since Kabutops can evolve from Kabuto of any expansion, you may use Rare Candy to evolve either Dome Fossil or Mysterious Fossil into any Kabutops, regardless of expansion.
Source: PUI Rules Team (2008-05-22)

Relevant cards

Note: All applicable cards may not be listed below.
BW10_105
BW10_85
BW5_100
DP4_102
EX13_90
EX2_88
EX9_83
HGSS2_82
POP5_7
POP8_10
SM1_129
SM2_165
SM7_142
SWSH1_180
SWSH1_180
XY5_135