Not to mention the SPD Red Ranger's entrance, one word and you know exactly who he is.
Adam sums up what every long time fan thought when they first watched Dino Thunder:
Kira: Dr. O would've loved to see that.
Adam: I still can't believe he's a doctor.
At the end of the second part, after the battle is won and the Rangers are hanging at the mansion, the writers managed to put in one last nod to SPD. Spencer walks in with a stack of toast for Bridge, and this exchange happens:
Bridge: Is it... *makes his little hand motion*
Spencer: ...The butter-est sir. *also does the little motion*
In one episode, Flurious says he has half a mind to turn Norg into a throw rug, and later says he has half a mind to shave him until he resembles a naked ice rat.
Norg: Half a mind... for a throw rug... half a mind, naked ice rat—Well, that only leaves one half left! Flurious: FIIIIIIIND MYYYYYY JEWWWWWWWWWWWELS!