Recent book, Probably within the last 5 years. Maybe newer. Might be a HaremLit book.
Unfortunately I only read the first few chapters and now I can't find it. (E-book version, don't know if a paper version was published)
Modern day, taking place in London(?) England.
Guy is attending University studying in the Campus library over a break period (Christmas break? Spring Break? Summer Break?) In any event not many people are on campus right now. There are 2 girls at another table studying. Other than the Librarian they are the only people in the Library.
I believe the girls are watching videos on their phones of strange things happening and not believing them. The guy might have also heard radio/tv reports of things happening before coming to the library, but did not pay attention to them.
The reports are of large animals appearing out of nowhere attacking people. (All over the world I believe, but I can only confirm in England.)
The latest cell phone videos clips the girls are watching and thinking are fake, show Dinosaurs coming out of portals and attacking people.
About that time, a raptor type dino comes racing in the room and charges them. They duck into the book shelf stacks and play hide and seek for a little while, before causing it to charge out of a window and fall (They were on like the 3rd or 4th floor)
They make their way down to the first floor and find the Librarian dead behind the counter.
The guys dorm is real close so they go there, seeing a few other raptors on campus attacking a few people. They are spotted on the way but make their way into the building before the other dinos get there.
They are in the room, and watching the news and seeing more videos of dinos. (Not sure if larger dinos types are involved.)
While in the room, one of the girls phone dies and she needs a charger to power it up to call her parents. She was from overseas. (Asian IIRC) And had not been able to get through or reach them. He does not have that type charger, and while they don't want to, they reluctantly agree to go to her dorm room to get one. (They will need to leave eventually cause he only had a food for a couple days)
Meanwhile, the dino who had fallen out the window (who they saw on the ground outside the library and thought was dead) has tracked them and while clearly injured, is now trying to get in his dorm room door.
Using homemade spears from broom and mop handles and kitchen knives, they attack the dino through the cracked open door and are able to kill it.
Then they go out side and start sneaking their way to the girls dorm.
That's where I stopped reading, and am now trying to find it to continue reading it.