Okay, so full disclosure, that image looks super goofy and put me off immediately. Also not particularly fond of the article itself. It's very long without saying a lot; a great deal of the detail in this is… fine, I guess, but it doesn't add a whole lot of stuff that interests me.
You said this was inspired by 1265, and I like that one too, but one of my favourite things about it is the more playful touches in it (the dinosaurs are all naked murder monsters à la Jurassic Park and people's stereotypes of them, then as they're discovered and better understood they become feathered and behave like actual animals). You've got a bit of speculation going on, but by and large this feels derivative without being as fun. It's obvious this is a subject matter you care about, but as it is, the rifts are more of the anomaly, the things coming through could pretty much be anything without changing much of the story.
The twist kind of comes out of nowhere; there's being subtle about it, and there's just not giving it the necessary buildup, as is, it's like solving a murder before we've even been told anyone's dead. Also, I kind of… just don't see dinosaurs taking back control of the planet, especially given that even with the increased numbers, there's not a great deal of them.
Is there an in-universe reason for the showing up in fossil hotspots? My knowledge of palaentology is definitely not what it was, but I was always under the impression that they were just places where conditions for fossilisation were favourable, rather than them having been more inhabited back in the day.
Technical issue, the names of species should be italicised, e.g. Dilophosaurus wetherilli
This is a pure question, rather than crit; is there any significance to the Sarcosuchus not showing up? It feels like a odd little aside that doesn't go anywhere, but me and missing the point go hand in hand.
I think, to boil it down, I'm not sure what you're trying to do with this, whether you're going for the mystery of why this is happening more, the sheer "hey aren't dinosaurs cool" or something else. In which case, my best suggestion would be to play up whichever element you like more. Having said that, I am but one person, and it's certainly worth getting as much feedback as you can before deciding to change something (or not changing anything, which is entirely possible).