I have this issue as well, which is quite nerve wrecking with not being able to see the zomdodos (sometimes or from the Dodorex tame). I'm not sure what actually caused it but I believe it's something Ark caused with the latest few updates because a lot has been broken since the last few updates, especially the feeding troughs.

ah ok i was getting worried it was one of the other mods cuasing it.

Same here. Zomdodos are invisible for some reason. And the sarco is not the only one with an plain model in my game. Tthe poisen wyvern also has an plain black model. + ApexCarnos just vanish after attacking them for some reason.

same sarco is white