Here is how I would do the time travel.
There is something called a Time Drive, it is similar to a Jump drive, making a jump using a time drive follows the exact same procedure as a regular Jump drive, except to make a time jump, one must be within 1 planetary diameter of a World greater than size 3. The Jump itself takes about a week. There are six varieties of Time Jump
100 to 600 years
1000 to 6000 years
10,000 to 60,000 years
100,000 to 600,000 years
1,000,000 to 6,000,000 years
and 10,000,000 to 60,000,000 years.
The last two are needed to reach the age of the Dinosaurs and just barely. The problem is that the ships required to make these last two kinds of time jumps are huge. A 1,000,000 ton starship equipped with a time drive makes the first jump to 60,000,000 BC and stays in orbit around the Earth back then, then a smaller starship with a 200,000 ton hull is released from the larger one and makes the final jump from 60,000,000 BC to 66,000,000 BC. And as per my time jump rules, each Time Jump Drive leaves a part of itself back at its origin point so it can be recalled. in the case of the larger starship, that point is in the campaign present, which could be Third Imperium Earth at around 1100 Imperial, in the case of the smaller starship that point is 60,000,000 BC. Both ships leave a part of themselves back at their point of origin when they make the jump back in time, for the smaller starships, it is a mini-black hole of the same mass as the starship which made the jump, but in the case of these capital starships, what they leave behind is a Time Jump Gate. The time Jump gate is actually the opening of a wormhole, in this case one that is 1 parsec long. An ordinary starship at the mouth of this wormhole can then make a regular 1 parsec jump inside the wormhole to the other end back in time.
The rules for making this jump is the same as that for making a jump to a neighboring star system, only the conditions created by the Time Jump Gate allow the starship to make a Jump at the mouth of the Wormhole, even though the jumpgate itself is located within 1 planetary diameter of Earth. (There are gravity generators along a ring at the mouth of the wormhole which flatten space in its vicinity allowing a jump to be made at the wormhole mouth.) The jump coordinates are relayed to the starship wishing to use the Jumpgate, after a toll is paid, the starship still needs the required Jump fuel for making a 1 parsec jump.
The first Jumpgate covers 60,000,000 years, the 1,000,000-ton starship at the other end of the wormhole uses its engines to keep the wormhole it left behind open and allow the passage of starships 1000 tons and under with their regular Jump drives, the 1,000,000 starship also acts as an orbital starport. As each jump takes a week to make, the starport allows the crew and passengers a chance to stretch their legs, peruse the various shops and eat at the restaurants here. Some distance away along an access tube wide enough to permit a 1000-ton or less starship to pass through is the second Time Jump Gate, this one covers the remaining distance in time of 6 million years, it takes another week to make the second Jump, the starport at 60,000,000 BC also sells Jump Fuel here, to starships with Jump 1 drives so it can make a second jump. The toll for travel back in time covers a two way trip, that is the trip back to the present for the same starship is covered by the initial jump toll. At the end of the second wormhole is the 200,000 ton starship which made the second Jump to 66,000,000 BC, this too has shops and restaurants and acts as the orbital component to the starport on the planet's surface. Jump fuel is sold at the usual price. Starships can then proceed from here down to the planet's surface in the usual manner.
The Earth at 66,000,000 BC boasts a Class A starport, as the ability to repair and construct starships under 1000 tons is very important here. The stats for the Earth at 66,000,000 BC are the following:
A867444-F The law level of 4 only applies within the ground of the time colony itself, if one strays out into the dinosaur infested wilderness, the law level is 0, as there is not the manpower to enforce the law globally, the planet is just too big and 10,000 people is not enough to do this job.
There are people who live out in the wilderness, typically they live by their wits, and no one questions their possessing military hardware to protect themselves from both beasts and bandits.
