You may be asking: WHY??? 

The cgi models shown in Jurassic World especially the Stegosaurus look nothing like their Lost World appearance back in 97. This is in fact true, many of the old familiar species designs really don't look like how we see them back in The Lost World, especially the Stegosaurus which suffers the most with the lack of beak and droopy tail (fixed until Dominion and Fallen Kingdom) while the Para and maybe Trike seems to resemble TLW model the more. However based on the concept art released for JW, the designs of Stego is literally traced 1 on 1 with the approved TLW concept art, which includes the droopy tail though the artist did seem to miss the beak. 

The JW Triceratops also seems to resemble the lost world and Jp3 cgi model more then the og JP Trike. Though the model in TLW and JP3 was just a modified Stego model since trike only made short cameos in those movies. This seems to clearly show the intention from ILM is that the JW animals are meant to be the same ones we see on Sorna back in 97, albeit obviously  flawed and mediocre recreation of them, maybe even rushed. But the intention is very clear. This also fits with lore on how Masrani Global pillaged Sorna to put the animals captured there on display for Jurassic World. It is still disappointing on what happened to Stego in JW though they did fix the model later in the sequels.

So I believe the better way to treat these design is that they are not new variants, they're the same animals as seen in The Lost World but different artstyle and medium. Like how Rexy looks different from JP compared to JW and Camp cretaceous/Chaos Theory and how the raptor squad color and pattern in Camp Cretaceous isn't a perfect match to their movie model. They are still clearly the same individuals, just different artstyle.

Hot take: the Jurassic World Stegosaurus, Parasaurolophus and Triceratops should not be considered to be their own variant but as the ones we see back in The Lost World Isla Sorna (Reasoning in below)