I've not seen the series in a while, but the time warp thing they would through could easily have deposited them somewhere else, or not as far in the past as they wound up in the tv series.
Also some could keep the extinct animal species as alt modes since they can scan fossils as I recall. Also some can take an idea from the Japanese series Beast Wars 2 where there are not pods, in the first 2 fan subtitled episodes I've seen. The characters seem able, at least in the Maximal case, of picking an animal and scanning it's dna to get their alt mode/beast mode. That is how the character the Tasmanian Kid, I think his name is. He crashes on a planet I think, is looking around or an animal to scan, picks a hawk or eagle or some other bird of pray, forgot the type, and right when the scan starts a tasmanian devil jumps at him and accidentally gets scanned instead.