Among the canyons of New Mexico, professional fossil hunter Stem Weathers is murdered. With his dying breath he gifts a notebook to a passerby, sending him to Weather's estranged daughter with a message. Frustrated, a shadowy assassin turns his attention to the new bearer of the precious notebook that documents the greatest paleontological find in Earth's history.
This novel provides examples of:
- Anachronism Stew: At one point, the titular T. rex comes across (and devours) a pack of Coelophysis, which already went extinct in the early Jurassic. This is jarring given the text earlier named dinosaurs and other fauna that were appropriate for the time period and region T. rex lived in (except for Deinosuchus, which died out 5 million years prior).
- Artistic License – Military: Part of Jimson Maddox's backstory is that he was a Gunnery Sergeant in the U.S. Army. Gunnery Sergeant is a Marine Corps. rank.
- Big Bad Ensemble: Corvus is murdered by Masago roughly two-thirds of the way into the book, leaving the latter to take over as the Big Bad for the rest of the story.
- Continuity Nod: Two characters are from a previous Preston novel known as The Codex. The events of that novel are vaguely referenced.
- Cool Car: Tom Broadbent's classically restored 1957 Chevy pickup.
- Cut Lex Luthor a Check: Cited and averted by Maddox. Instead of networking in prison to advance his criminal career, he used his contacts to make a dating site called Hard Time for women seeking convicts. He comments in other places that if he had known how easy it was to make money legitimately, he never would have bothered with crime. It's played straight, however, in that Maddox does highly illegal things, albeit because 1. He's grateful to Dr. Corvus for springing him from prison. And 2. He knows Dr. Corvus can put him back in prison if he screws up on his One Last Job.
- Darkness Equals Death: Corvus' last scene. Played with in that the victim fled into the dark room for safety and potential ambush, not counting on the hunter to be better equipped and experienced in just such a situation.
- Diabolical Mastermind: How Corvus styles himself, but he's a relatively anemic example.
- The Dragon: Weed Maddox. Ex-con (thanks to Corvus) with military training, sociopathic tendencies, and tactical ruthlessness. Also he runs a dating website.
- Dumb Dinos: Zig-zagged; while the titular T. rex is highly intelligent, she's also a being of pure instinct - she doesn't remember anything, not even mating rituals or raising her young, and only lived to eat.
- Faux Action Girl: Sally Broadbent. She teaches horsemanship and is supposedly a crack shot; she even reassures her husband that she'll be fine if left alone for a weekend. Then she's captured without much fuss, bungles an escape attempt, and spends the rest of the story being present while Tom and Ford save the day.
- Feathered Fiend: The titular T. rex is portrayed with a downy coat of feathers. Pretty commendable, for a work written in 2005.
- Honor Before Reason: Broadbent promises to fulfill Weathers' Last Request of delivering Weathers' notebook, even though it's not his responsibility and doing so places his friends and family in danger. He could just hand the notebook over to the police for delivery at any point; worse, in delivering it he's a potential accessory to grand theft since the fossil is on public land.
- I Gave My Word: See Honor Before Reason above.
- I Surrender, Suckers: Ford to Masago.
- The Lab Rat: Melodie Crookshank, who is literally only depicted working in her basement lab on heavy science-y stuff.
- Last Request: Weathers to Broadbent, asking him to deliver the notebook to Weathers' daughter.
- One Bullet Left: The weapon Broadbent steals only comes with a single round. Averted; the shot is downplayed and Broadbent has to menace The Dragon with an empty gun.
- Only a Flesh Wound: Broadbent is shot in the face at point-blank range and is only momentarily unconscious for it, though it's suggested there may be a concussion and bone creasing.
- Outside-Context Problem:
- In a story about an unscrupulous museum curator poaching the claim of a fossil hunter, it's a bit unexpected when a US military black-ops detachment shows up in the fourth act.
- Even more so, the Tyrannosaurus was killed not in combat nor in old age, but by extraterrestrial forces.
- Phlebotinum Killed the Dinosaurs: In this case, an alien bacteria that may have been an engineered bioweapon.
- Police Are Useless: Left and right.
- Detective Lieutenant Willer disbelieves Broadbent's account of Weathers' murder after a cursory search until Broadbent personally uncovers incontrovertible evidence.
- The same police fail to follow up on the investigation quickly, allowing evidence to degrade.
- Willer continues to follow Broadbent as a person of interest and intercepts his vehicle while Broadbent is negotiating for a hostage exchange.
- Finally, Willer is rendered impotent by the appearance of federal forces right before he might have been useful in the desert.
- Broadbent himself seems to believe this when he doesn't contact the police in the wake of Sally's kidnapping.
- Red Herring: Weathers asks Broadbent to deliver his notebook to his daughter Robbie in the first few pages. Broadbent spends the rest of the story chasing the notebook, only delivering it to Robbie in the last few pages once the entire plot is resolved.
- Self-Made Man: Broadbent's family was wealthy, but he turned his back on the family connections to start his own business as a veterinarian. He's known to be quite wealthy but hasn't touched his inheritance because he wants to make his own money.
- Steel Ear Drums: Maddox fires multiple times in the close quarters of the cave sequence with no apparent ill effects. When another character is shot in the face point-blank, the biggest concern is a concussion rather than permanent hearing loss.
- Thirsty Desert: The mesas of New Mexico. Thirst becomes a real, immediate concern for several characters through the later parts of the book.
- Viewers Are Geniuses: Almost any scene involving Melodie Crookshank will be heavy on technical terminology and light on explanation. Justified since she's only speaking to herself or other professionals who already understand, but difficult for average readers.
- Weapon for Intimidation: Biler's stolen .22, after the one bullet is fired.
