Every Giant Tyrannosaurus rex Specimen Explained | Megatheropod Paleontology

本站添加: 2026-05-12

[00:00:00]T-Rex is the therapod, the gateway dinosaur into paleontology. With so many specimens discovered in the 120 years since its description, it's extremely wellstudied and has provided the bulk of our understanding of megaod biomechanics and behaviors. Part of the fun of working with megaods is figuring out which primeval apex predator was top dog in terms of body size, and that's no different within Tyrannosaurus itself.

[00:00:24]Today, we're covering all of the giant T-Rex specimens discovered as of May 2026, using cuttingedge research to determine which tyrant lizard was truly the king.

[00:00:41]Thanks to the research team I work with with Zongchu Gi, Frank Fang, Dino W, Kyle Atkins Welman, and Eric Snively, the data and sizes you're about to see for various T-Rex specimens represent for most individuals the cuttingedge results of the most advanced and lifelike reconstruction techniques yet developed. They've been working with museums, other research teams, and private institutions in order to collect a database of 3D scanned megaod skeletons, and the results are fascinating. I've been lucky enough to observe this process, and I'm stoked to share what I can with you. Thank you to Super Masterpiece 34 for collecting the majority of these scans and for giving permission to share their measurements.

[00:01:16]First, we need a reference point. What does giant even mean in context of Tyrannosaurus Rex? We only have a handful of confirmed adult T-Rexes to begin with, and they're mostly on the larger end of the specimens we have preserved. We'll be covering those adults as well as individuals without confirmed ages that have measurements comparable to adult specimens. We'll start out with a few wellestablished specimens with highly detailed reconstructions so you can have a reference for some of the scaling we'll be doing later in the video. After the reference specimens, we'll go from smallest to largest, examining each Rex's stats and cool facts so we can decide which ones count as truly giant.

[00:01:50]For some individuals, scans were not available, so size calculations are based on comparisons with other specimens. To clarify, I'm not saying anything against skeletal artists.

[00:01:59]People like Scott Hartman, Dan Folks, and Random Dinos work hard and do their best to provide accurate and precise results. But this video will clarify quite a bit of information that has either been misreported in the literature or only vaguely described.

[00:02:11]View it as a supplement rather than a replacement, with scans allowing for a much better understanding of measurement standards than 2D images can provide. We should also mention age. The growth stage of a given specimen can be difficult to infer or calculate without hisystological examination of the cross-section of bones, a process that basically lets you look at growth rings in animals like you can with a tree.

[00:02:32]Only a handful of T-Rex specimens have been hisytologically analyzed, and an even smaller number are fully grown. So, I won't overclaim here. If we don't know a specimen's age, I won't pretend that we do. I'll be honest about when we're guessing. On that note, let's get started with our three reference specimens. AM&H5027, Stan, and M555. AM&H5027 or Roberta was the public face of Trannosaurus for nearly a century.

[00:02:56]Discovered in 1908, this specimen isn't the holotype, but might as well be in terms of cultural impact. It's reportedly the specimen that inspired Rexi from Jurassic Park, which revolutionized how dinosaurs viewed in popular culture. It's also the specimen that comes to life in Night at the Museum. Surprisingly, for such an iconic specimen, it's rather small. A 2020 study classified it as on the line between young adult and adult with a notable amount of growing left to do.

[00:03:20]Although I will stress that it was based on body morphology rather than actual hisytological work. Any specifics about its age are guesses. At any rate, having a small possible adult weigh in at 7.2 tons is a great reference to use, especially since we know the skull and illium length to compare with other specimens later on. A 2025 paper found a higher mass for the specimen, about 7.9 tons, but that was based on predicting soft tissue levels using an equation based on modern birds and lizards. More detailed muscle-based models from the same authors result in lower masses.

[00:03:50]Stan is one of the most immediately recognizable and iconic Tyrannosaurus specimens out there. Discovered nearly 40 years ago, he's been reproduced in cast form for dozens of museums across the world thanks to his high degree of completeness and is currently on display at the Natural History Museum of Abu Dhabi. The most detailed volutric models available yield between 9.1 and 9.7 tons for this 11.8 m Rex. Stan is what's called a false graile rex. Its femur circumference is weirdly low for the size of its skeleton. So, if you went off femur measurements alone, you'd think it was much smaller than it actually is. Devil Rex is perhaps the coolest name for a Tyrannosaurus specimen ever. So, I'm a little biased towards this guy just for that. It's also the skeleton that my wife and I got to see on our honeymoon, which was a week-long tour of all the museums that the Smithsonian had to offer. Devil Rex's mount, depicting it about to rip the frill off a triceratops, is undeniably epic. A 2025 abstract by the team I'm lucky enough to work with reconstructed Devil Rex on a muscleby muscle basis using 3D scans of the material and arrived at 9.4 tons for the beast. It helps that the specimen is mostly complete with 80 to 85% preserved. So, it's a great addition to our pool of reference skeletons. onto the other potentially adult specimens.

[00:04:58]Starting with the smallest, it is incredibly difficult to find any good information about the T-Rex custer M8.

[00:05:05]The specimen is just a skull that experienced significant distortion, which adds another layer of complication to size estimation. The maxul is restored as too long and drawn out, and the actual measurements from Pete Larson along with a corrected reconstruction by Paleo Joe indicate an animal with a 1.34 to 1.4 me skull in life. That's barely larger than Aiman H527 and smaller than M555 suggesting an approximate body mass of 7600 kg. We also don't know the age for this one. Although CAR 2020 suggests adulthood, it seems to be on the small side. Huxley is short in terms of length. That is to say, it's short anteroposteriorly from head to tail, not long sheesh English. It is however quite tall and robust, somewhat resembling a compressed maple bar of a Rex, and so would have weighed a decent amount despite not being terribly long.

[00:05:50]somewhere on the order of 7.9 tons.

[00:05:53]Huxley was 22 years old as established by Ericson at all 2024, but was still growing as evidenced by the lack of an EFS or external fundamental system.

[00:06:01]That's a series of very closely packed growth rings that indicate an animal had seized meaningful growth. Young adult seems to be the best term to describe this animal. Unfortunately, there's not much to say about M980, also known as PEXRex. As far as I can tell, it hasn't been used in many scientific studies. We don't know how old it was when it died, and its size is rather unremarkable at only 8.5 tons. It has a neat mount at the Museum of the Rockies, however, and is believed to have suffered from a bacterial infection in its jaws that would have made fighting and feeding rather painful. Tristan Otto also had a bone infection at his jaw. CT scans in 2021 demonstrated the presence of reactive bone growth at the bottom of Tristan Otto's deny or lower jaw. This growth likely resulted from bacterial infection. Tristan is held at the Berlin Natural History Museum on loan and is plausibly a young adult of 20 years old, although skeletal maturity has not been verified. With a body length of 11.76 m, hip height of 3.82 m, an estimated body mass of 8.8 tons, Tristan is essentially the black T-Rex from Dinosaur King, but in real life, and may have still had some growing to do. Plus, it has actual black bones stained by the clay it was buried in. How cool is that? Victoria is an incredible specimen. According to Bucky Deringer, histologology analysis by Philip J. Curry indicated she was about 17 years old at time of death with a good chunk of growing years ahead of her. And yet, despite her youth, she was already nearly 12 m long and weighed at least 9 tons. According to a volutric analysis by Oliver Demouth in 2021, she's a great example of the sheer robustity that Tyrannosaurus could reach even when young and was built like a battering ram. Maybe we should have named her Grond. Actually, let's save that for a super gigantic sereratops in Kyosaurid. Foxy lady is a specimen that I got to see when my wife and I visited the Black Hills Institute in October 2025. Portions of the skull and some of the teeth were on display there, and Pete said that the rest of the material is planned to go on display relatively soon as well. The deny is the only public measurement, which alone would indicate an animal roughly the size of Stan, but apparently the rest of the material is larger than each corresponding element in Stan. To be safe, let's go with at least 9.2 tons, although she's likely larger. RGM792000 or Trixs was discovered in 2013 and is currently on display at the Naturalis Museum in the Netherlands. At between 24 and 30 years of age, she's a mature adult and is actually the smallest T-Rex that's hisytologically verified to be skeletally mature. She's short, and I say she for convenience due to the specimen's name, not because we know the gender, but robust with a rib cage 1.48 48 m wide, built like a sausage pretty much, almost like a T-Rex took a peek down at South America, saw all the cool abellosaurus down there, and decided to give that body shape a shot. Trixs, according to scanbased life recons down to the level of individual muscles, would be about 9.3 tons in life.

[00:08:35]Remember, smallest verified adult. SDSM 1247 was discovered 46 years ago at the time of this video's writing. It's not bad material with almost an entire articulated skull along with a partial cervical series, ribs, an illium, the left femur, tibia fragments, and several codle vertebrae. Comparing the scan of the skull to that of tricks revealed it to be slightly larger, which surprised me given how I expected it to be a smaller individual. Thanks to robust morph for performing that analysis. It wouldn't surprise me if this were a subad adult or young adult based on how narrow the back of the skull is, similar to the gradually broadening morphology we've seen in the Duffy specimen, although a bit larger. The cool part about the mudbrex or scarface is the gnarly pathology on its left maxul.

[00:09:12]Reactive bone growth that could have been caused by injury or disease has severely affected the bone here and caused it to thicken in response to trauma. Tyrannosaurus Rex wasn't properly established as a genus until 1905 in the same paper as Dynamosaurus actually although that taxon was absorbed back into T-Rex a year later.

[00:09:28]The holotype of T-Rex is now known as CM9380 and is on display at the Carnegie Museum. It's surprisingly quite fragmentaryary despite being the basis for the species with only 11% of the skeleton preserved, but those portions are much bigger than I thought before beginning the research for this video. I have to apologize to Arwin. Actually, in a previous video, I stated that it was smaller than the Gigonatosaurus holotype, and after reviewing the material, I realized that is very unlikely to be the case. Arwin's skull is much shorter than the outdated Giga Mount Recon, but she has a more robust femur, a much longer tibia, a thicker tail, and a pelvis that's 50% larger. A 2011 study using laser scans of the fossils found an average mass of just over nine tons, which was with the super low density values of the early 2010s and would translate to 9.7 tons with today's knowledge of large arosaur densities. That aligns well with scaling from the dampl 2025 reconstruction of ammon H527 as well as the geodol 2025 uber detailed recon for 555. Between 9.2 and 9.7 tons for Arwin seems like the best range. Not bad for such an iconic specimen. It's also worth mentioning that the torso of the mount is restored as proportionally too small for its vertebrae, which are actually among the largest of any known theropod specimen, period. I I don't love maxul scaling, even though there's quite a lot of more material to CM1400 that's just never been described. The maxula is the only element I could find measurements for.

[00:10:46]Maxula size and proportions are highly variable traits in therapod, so I struggled to take this one very seriously. It might have been between 9 and 10 tons, but until the post cran are described, gorbag is a big mystery. It was described as a morphological adult in a 2020 study, if that means anything.

[00:11:01]Although that study still included nanotyrannis in a T-Rex growth curve, so its age brackets are a little suspect.

[00:11:06]Who knows, if you're watching this video, you could be the person to describe the full material one day. The first Tyrannosaurus ever discovered, BMHR7994, was originally referred to as Dynamosaurus Imperiosis, a chimeic animal composed of this Rex material and Enkyosaurus scoots found with it. Those scoots appeared to have bite marks in them, testaments to the tyrant lizard king's biting power. While the skull was highly fragmentaryary, enough was preserved of the skeleton to permit identification as an enormous carnivorous dinosaur. Its proportions seem odd with a skinny femur but enormous skull and spinal column. It's likely in the 10-tonon range given how its axial skeleton seems to be slightly smaller than that of Sue. G-rex is one of the scariest individuals on this list. A 2004 study by her and Padian found that this T-Rex, known only from a large femur, was 17 years old and growing rapidly at the time of death.

[00:11:53]The femur is huge already at 1.26 26 m long from greater trocanter to lateral condile and 580 mm wide, nearly as wide as Suz. Comparisons with devil rex suggest a mass of approximately 9.8 tons based on its length and circumference.

[00:12:07]If G-rex had lived to become a skeletally mature adult, it likely could have gained another couple tons to rival the biggest Rexes out there. Even though its growth was cut short by mortality, it was already bigger than pretty much every therapod not named Tyrannosaurus or Zushang Tyrannis and was comparable to the old high-end estimates for the Denry Giga. Scotty is a beast and is by far the largest therapod ever discovered in Canada. It took 20 years to excavate the entire thing and it wasn't until 2019 when Scotty was recognized as one of the most massive Tinosaurus specimens ever discovered. Persons at all 2019 calculated a rough mass estimate based on a restored femur circumference and got 8,800ish kilograms, higher than what they got for any other specimen. Scans indicate that its size relative to other specimens may have been overestimated, but the raw numbers are far higher than femur alometry indicates. Volutric models consistently obtain between 10.4 and 11 metric tonses. Scotty is one of the few Rexes believed to be fully grown based on histological analyses. So, if you've been paying attention, you'll notice that adults tend to cluster in the 9.5 to 11 plus ton range. Goliath blew up the internet in February 2025 when the gigantic femur was displayed at the Tucson Rock Show and its measurements were posted online. My friend Brian traveled to the show to verify the measurements via scan as well as physical methods and seconded that the femur was absolutely enormous. I've received reports of conflicting measurements from anonymous sources, hence the question marks. But I'm comfortable with saying that Goliath is at least comparable to Scotty. It's still one of the biggest Rexes out there, even if my anonymous sources turn out to be accurate in their interpretation of the material. 11 tons on the low end is not a bad place to be.

[00:13:38]Cope is my favorite Tyrannosaurus specimen. How could it not be with all of the work I've done with it over the last 3 years? Portions of the vertebrae were discovered by Ed Cop in 1892 and left in a stack to mark the fossil site.

[00:13:48]My friend Bucky found the maxula hanging out of a hillside in 1998, only a few feet away from a stack of lych and encrusted vertebrae. An excavation of the rest of the material lasted until 2007. We went back to check out the site in 2025, and found some fragmentaryary codle vertebrae, which according to our scans were comparable in size and shape to those of Sue. Cop's tibia and fibula are extraordinarily long, potentially indicating that he was better adapted for moving quickly than other big rexes.

[00:14:12]And he also has the thickest theropod femur ever published with a minimum circumference of 630 mm. The skull material is about the same size as Sue's, perhaps slightly smaller. Pete Larson and I are just waiting to get the scans of the rest of the material from Cop's current owner so we can describe the specimen. Out of all of the rivals to Sue's crown, Cope is the only one with a serious chance of overthrowing her. The only thing standing in his way is publication. Sue, at least for now, remains the publicly recognized queen of kings. Sue's secret is her extraordinary robustity with an enormous rib cage, the largest dorsal verts ever published for a theropod, and long legs that give her a hip height of nearly 4 meters, not accounting for soft tissue in life.

[00:14:49]She's built like a tank with a skull almost 1.6 m long that could crush bone and muscle into paste. Based on public measurements alone, Sue exceeds 11 metric tons and is about 12.7 m long.

[00:15:00]However, the same biomechanics and anatomy team that calculated Devil Rex at 9.4 4 tons and tricks at 9.3 using muscle level recons puts Sue at over 13 tons, basing musculature off of how much is needed to plausibly move an animal that large. Just the abstract is currently available, but more is coming soon. It's planned for later 2026. As of the time of this video's writing, it's become moderately absurd how Tyrannosaurus body size has changed over the last 20 years. We went from the emaciated GSP inspired 5-tonon numbers that weren't anatomically or biomechanically feasible to fully muscled, rigorously tested 10 plus ton giants. Turns out, as technology and methods improve, so do your models. Many of these advancements resulted in much higher mass estimates for other theropods in general. Gigganoturus and Carrodontosaurus are over 8 tons now.

[00:15:44]Acroanthossaurus surpasses six. Volutry has become widely regarded as a more precise method for restoring individual skeletons using anatomy and holistic measurements to predict mass rather than equations. The question on everyone's minds is as paleontology continues to increase in popularity, when will we find a theropod that's definitively as large as or bigger than Tyrannosaurus.

[00:16:05]As soon as that question gets answered, you'll know where to find the coverage.

[00:16:08]Right here on Vividen Paleontology Evolved. As always, you can help to support me by either joining the channel or by checking out my book, Extinction Obsidian Dawn, which covers a conflict between nations and pantheons in an alternate world where psychic bonds with prehistoric animals influence warfare. I also recently started a video series covering different animal cades and why they're incredibly amazing, so you might enjoy watching the playlist.

[00:16:29]Carrodonttoidurids, spiders, elas, megarapins, and pseudosukians are the ones I've covered so far. Comment with your favorite prehistoric animal group that you want me to do a deep dive on.

[00:16:38]I'm the Vividen and I'll see you the next time I nerd out over unimportant but really cool aspects of mega therapod biology.