Originally conceived as a miniseries to promote Hasbro's new toyline, Marvel's Transformers series ended up running 80 issues from 1984 to 1991. Alongside the main series, Marvel also published a slate of spin-offs including G.I. Joe vs. Transformers and Headmasters, an adaptation of the 1986 animated film, and original material that ran over the course of 330 weekly issues of the Marvel UK series.
The chief architect of the UK material was writer Simon Furman, who was tasked with crafting stories that could literally fit between the pages of the American issues, since the weekly schedule of the UK series required far more material than the American series could provide. Over in America, the majority of issues were written by Marvel editor Bob Budiansky, who was also responsible for assigning names and personalities to the cast of transforming robot molds Hasbro had licensed from Japanese toy companies. Budiansky's run wrapped up with 1989's Transformers #55, and on his recommendation, Furman was invited to take over the American series, as well.
Furman has contributed to new Transformers comics continuities over the years, helping to reimagine the mythos for both Dreamwave and IDW Publishing. In recent years, however, IDW has allowed Furman to return to the original continuity created for the Marvel series. Going back to the 1980s is nostalgic fun, of course, but there is an issue when creating new stories set between the adventures of an old Marvel comic. As evidenced by an appearance from a certain wall-crawling wonder in the third issue of the series, Transformers was firmly set within the Marvel Universe.
In 202, IDW's Transformers '84: Secrets & Lies saw Furman teamed with artist Guido Guidi to create a prequel series for the Marvel continuity. The premise reveals untold details relating to the Autobot/Decepticon war, following the crash landing of Autobot leader Optimus Prime's ship, the Ark, on a prehistoric Earth. The miniseries is narrated by Counterpunch, an Autobot double-agent working within the villainous Decepticons' army. As the story is set literally millions of years in the past, it's easy for the creators to avoid any references to Spider-Man's eventual encounter with the Transformers. The Dinobots, however, are a stickier issue.
In the fourth issue of the original Transformers series, Optimus Prime studies their ship's computer records, collected during the millions of years they were inert, following their crash on Earth. (The issue is from writer Jim Salicrup's brief stint as writer, who's acknowledged he wanted to bring more of the Marvel Universe into Transformers.) He discovers five other Autobots existed on Earth while the others were inert. These are the Dinobots: Grimlock, Slag, Sludge, Snarl, and Swoop. Intrigued, Optimus Prime orders a probe to go and investigate what might've happened. It lands in one of Marvel's most famous locales, the Savage Land.
The Savage Land is a prehistoric territory, hidden within a tropical preserve in Antarctica, and it's the intellectual property of Marvel Comics. The idea is inspired by "The Land Where Time Stands Still" from 1941's Marvel Mystery Comics #22. Stan Lee and Jack Kirby reinvented the concept, and christened it as the Savage Land, in 1965's X-Men #10. It's a mainstay of X-Men continuity, and the home of Marvel heroes Ka-Zar and Shanna, the She-Devil.
Transformers #8, an early issue in Budiansky's run, gives the Dinobots their origin. Following the Ark's crash, its computer detected the Decepticon Shockwave landing in the Savage Land. The Ark exerted the last of its capabilities to revive five Autobots and patterned their alternate form on the Savage Land's dominant life, dinosaurs.
In the battle's aftermath, the Dinobots were trapped in a tar pit and remained dormant for millions of years. Following a surprise attack from Shockwave in the present day, Transformers #8 has Autobot medic Ratchet traveling to Antarctica to find the Savage Land and revive the long-lost Dinobots.
Placing Shockwave in the Savage Land might initially seem a curious choice, given that non-fictional dinosaurs existed at the time, so it's not as if you needed a Savage Land for the Dinobots' origin. However, aside from tying the Transformers' lore to Marvel lore, the initial story explains away any issues relating to the Dinobots representing dinosaurs from different historical eras. They all co-exist, whether they be Jurassic or Cretaceous, in the Savage Land.
According to Counterpunch's Secrets & Lies narration, the story of the Dinobots' reactivation involves "a lot of apocrypha", and one version even features "actual, living dinosaurs," an obtuse reference to the Savage Land's role in the Dinobots' origin. As IDW has no legal right to feature the Savage Land in new material -- even in Furman's annotations, he only refers to it as "The Original Location" -- Furman forges ahead with an alternate origin for the Dinobots.
Transformers '84: Secrets & Lies features Autobot computer AUNTIE rebuilding the Dinobots, here portrayed as the "Dynobots," a more recent idea that appears in some versions of canon. The Dynobots are not random Autobots selected to become dinosaurs, but an established team of rough warriors. (Who just so happen to have a name that sounds like "dino-bots.") Their rebuilding scene is based off a sequence in Transformers #8. However, the images on the Ark's screen now show fossilized dinosaur remains instead of the Savage Land's living dinosaurs.
This is tricky territory, as the entire point of the miniseries is to give diehard fans a story that fits snugly into the past, and flagrantly contradicting a beloved run from early in the canon's history is likely to irritate the target demographic. Furman does have some cover, however. The Dinobots' battle with Shockwave was largely presented via a memory probe on the Dinobot Slag in Transformers #8. Readers only see the events that Slag witnessed, before falling into a tar pit and blacking out. Additionally, Counterpunch's recounting of these events is also secondhand, by his own admission, indicating that he might also have some of these facts wrong.
Beyond that, Furman also uses Secrets & Lies as an opportunity to cover some plot holes from the earliest Transformers comics. When Grimlock smashes the rogue AUNTIE, readers are given a justification for why the Ark's onboard computer made no further efforts to awaken its crew, during the massive gap of 4 Million BCE and 1984 AD. This is also a simple explanation for why AUNTIE could correctly identify organic dinosaurs ages ago in the past, yet later mistake automobiles for Earth's dominant species (an essential element of the Transformers' origin.) Whether or not readers accept this supplemental material as the true canon is their personal choice, but it is a clever means to work around the unique legal issues surrounding the Transformers' past.