Revealed:
"Autobots"
Light Long - Lightning
Hydrophant - Water
Ignite Bite - Fire
Drill Horn - Earth
"Decepticons"
Captain Volka - Fire
Leafback - Grass
Thunder Beak - Lightning
Spirituan - Earth
Unrevealed:
Abyss Rain - Likely the Decepticon/Dinosaur water elemental. Would love for this to be a plesiosaur of some type.
Lavamuleta - This one is confusing, because both sides already have a fire and an earth elemental, which seem to be the most likely alignments of someone with "lava" in their name. Maybe indicating that there are more than one of each element available to each side?
Frost Saber - A saber toothed tiger? Maybe with a new "Ice" element? If it is a saber tooth, maybe it could fit into either team? It would be a mammal, but also a prehistoric animal. Complete speculation, though.
Sky Report - Probably the Autobot aligned flyer to counter Thunder Beak. "Grass" is the only element that is missing from the Autobot team, unless like I mentioned earlier, there are some more elements yet to be revealed.
EDIT:
I'm seeing elsewhere that rumors are that Lavamuleta is a bull that transforms into a shield and Frost Saber becomes a sword. These would be packed with the Nemesis Prime and Shadow Megatron repaints. If so, that makes sense. Sky Report would be a grass-elemental "Autobot", giving each team 5 members, with Lavamuleta and Frost Saber being seperate weapons instead of directly forming limbs/wings (they may still be able to be limbs, but it wouldn't be their primary purpose.)
EDIT PART 2: Electric Edi-loo
Ok, apparently two of the unrevealed animals are a bull and a stegosaurus as shown in these to teeny-tiny pics:
I'd wager Abyss Rain is gonna be a blue stegosaurus as the Decepticon water-elemental.