Forest

Blue, Loyal Raptor

Partner with Owen Grady, Raptor Trainer (When this creature enters, target player may put Owen into their hand from their library, then shuffle.)
For each kind of counter on Blue, Loyal Raptor, each other Dinosaur you control enters with a counter of that kind on it.

Gigantosaurus

Life Finds a Way

Whenever a nontoken creature you control with power 4 or greater enters, populate. (Create a token that's a copy of a creature token you control.)

Hunting Velociraptor

First strike
Dinosaur spells you cast have prowl {2}{R}. (You may cast a spell for its prowl cost if you dealt combat damage to a player this turn with a creature with any of its creature types.)

Savage Order

As an additional cost to cast this spell, sacrifice a creature with power 4 or greater.
Search your library for a Dinosaur creature card, put it onto the battlefield, then shuffle. It gains indestructible until your next turn.

Mountain

Cresting Mosasaurus

Emerge {6}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When this creature enters, if you cast it, return each non-Dinosaur creature to its owner's hand.

Island

Owen Grady, Raptor Trainer

Partner with Blue, Loyal Raptor
{T}: Put your choice of a menace, trample, reach, or haste counter on target Dinosaur. Activate only as a sorcery.

Ravenous Tyrannosaurus

Devour 3 (As this creature enters, you may sacrifice any number of creatures. It enters with three times that many +1/+1 counters on it.)
Whenever this creature attacks, it deals damage equal to its power to up to one other target creature. Excess damage is dealt to that creature's controller instead.

Raptor Hatchling

Enrage — Whenever this creature is dealt damage, create a 3/3 green Dinosaur creature token with trample.