New Horizons

Enchant land
When New Horizons enters the battlefield, put a +1/+1 counter on target creature you control.
Enchanted land has "{T}: Add two mana of any one color."

Plains

Imperial Aerosaur

Flying
When Imperial Aerosaur enters the battlefield, another target creature you control gets +1/+1 and gains flying until end of turn.

Forest

Rootbound Crag

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Spike-Tailed Ceratops

Spike-Tailed Ceratops can block an additional creature each combat.

Bellowing Aegisaur

Enrage — Whenever Bellowing Aegisaur is dealt damage, put a +1/+1 counter on each other creature you control.

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ancient Brontodon

Frenzied Raptor

Ravenous Daggertooth

Enrage — Whenever Ravenous Daggertooth is dealt damage, you gain 2 life.

Gishath, Sun's Avatar

Vigilance, trample, haste
Whenever Gishath, Sun's Avatar deals combat damage to a player, reveal that many cards from the top of your library. Put any number of Dinosaur creature cards from among them onto the battlefield and the rest on the bottom of your library in a random order.

Tilonalli's Knight

Whenever Tilonalli's Knight attacks, if you control a Dinosaur, Tilonalli's Knight gets +1/+1 until end of turn.

Savage Stomp

This spell costs {2} less to cast if it targets a Dinosaur you control.
Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Kinjalli's Caller

Dinosaur spells you cast cost {1} less to cast.

Commune with Dinosaurs

Look at the top five cards of your library. You may reveal a Dinosaur or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Priest of the Wakening Sun

At the beginning of your upkeep, you may reveal a Dinosaur card from your hand. If you do, you gain 2 life.
{3}{W}{W}, Sacrifice Priest of the Wakening Sun: Search your library for a Dinosaur card, reveal it, put it into your hand, then shuffle.

Mountain

Dinosaur Stampede

Attacking creatures get +2/+0 until end of turn. Dinosaurs you control gain trample until end of turn.

Steadfast Armasaur

Vigilance
{1}{W}, {T}: Steadfast Armasaur deals damage equal to its toughness to target creature blocking or blocked by it.

Charging Monstrosaur

Drover of the Mighty

Drover of the Mighty gets +2/+2 as long as you control a Dinosaur.
{T}: Add one mana of any color.

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Ixalli's Diviner

When Ixalli's Diviner enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Territorial Hammerskull

Whenever Territorial Hammerskull attacks, tap target creature an opponent controls.

Snapping Sailback

Flash
Enrage — Whenever Snapping Sailback is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Ripjaw Raptor

Enrage — Whenever Ripjaw Raptor is dealt damage, draw a card.

Demystify

Colossal Dreadmaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Pterodon Knight

Pterodon Knight has flying as long as you control a Dinosaur.

Thrash of Raptors

As long as you control another Dinosaur, Thrash of Raptors gets +2/+0 and has trample.

Ixalli's Keeper

{7}{G}, {T}, Sacrifice Ixalli's Keeper: Target creature gets +5/+5 and gains trample until end of turn.

Forerunner of the Empire

When Forerunner of the Empire enters the battlefield, you may search your library for a Dinosaur card, reveal it, then shuffle and put that card on top.
Whenever a Dinosaur enters the battlefield under your control, you may have Forerunner of the Empire deal 1 damage to each creature.