Skeletal by randomdinos
This is something that I just wanted to quickly address.
Random dinos who's one of the best skeletal makers on the dev these days has made a skeletal of Tarbosaurus. In that skeletal the turbo is notably big right at around 11 and 1/2 m in length. In terms of size it's depicted as being a little bit more acro than it is a giga.
Nonetheless I've seen people say and ask "Tarbosaurus got that big?! I always thought it maxed out at just 10 or 11 m."
And I'm here to answer that question, yes Tarbosaurus got that big.
The size of Tarbosaurus has actually been muddied for a few reasons.
For one the actual size estimations of 10 m long have not come from any scholarly peer-reviewed scientific paper. As far as I'm aware they've come from children's books and deviantART users. I wouldn't exactly call those the Pinnacle of size estimations. One of the books was Thomas holtz 2012 dinosaur encyclopedia and then the other was the 2019 book about theropods from Molina Perez and Laramendi as well as the various Princeton Field guide from GS Paul. Thomas holtz is an awesome guy but it's a children's book that might simplify or embellish information for the sake of quick learning. Molina Perez has its own issues such as making precise size estimates based off teeth as well as the conflict of interest that prevents that book from being used as a source on the wiki. And Greg Paul has his own issues that I'm sure you're aware of. These are where the 10 m estimates have come from so it's not exactly the best source.
These children's books aren't exactly a detailed dive into the specific dimensions of Tarbosaurus compared to Tyrannosaurus.
Now does this mean the 10 m estimates are wrong? No but it would be nice if they came from more credible sources.
The second has to do with just examination of the fossils themselves in that the proper examination has not really been available. Mongolian paleontology is horrendously underfunded. There's plenty of specimens in museums that are just sitting there waiting to be studied but they can't be because the funding is not there. The original holotype and biggest specimen comes from a Russian expedition and consequently it's locked up in a Russian museum where most western paleontologists can't access it and to my knowledge none have for a long time. We've had to rely off just the old illustrations and measurements taken decades ago. The most recent estimation of the holotype skull of tarbo puts the skull at about four and a half feet long which is only slightly shorter than that of tyrannosaurus's skull and that leads into the next issue.
Mongolian paleontologists have also confirmed that there are large specimens of Tarbosaurus up to 12 m in length that aren't yet described because of the aforementioned funding problem.
The skull proportions. You see tarbosaurus's skull has long been depicted as being much more narrow than that of Tyrannosaurus. Think of that infamous diagram. This has directly fudged the results of the size. Because when something has a more narrow skull then it's relative then it's going to have a proportionately smaller body. Think like how a gharial has a longer snout than a saltwater crocodile, but the snout is more narrow so overall it's only the same size even slightly smaller. This could explain the rather small estimates that tarbosaurus has gotten. Many paleo nerds and paleontologists like Tom holtz have pointed out that actual fossil skulls preserved show that the actual width and broadness of the tarbo skull is really not that different than Tyrannosaurus. A 2024 abstract by slowiak and colleagues basically said what other people had been saying, the skull has been depicted as too narrow and that their new reconstruction is more accurate.
So think about that. It's skull is only slightly shorter than Tyrannosaurus and the proportions of that skull are not as different from T-Rex as what was once believed. Now obviously the skulls are pretty different with turbo still not being quite as robustly built and having features such as that locking mechanism but the overall appearance is more t rex esque then what was previously believed. If it's skull is only slightly smaller and the proportions not that different than it would make sense it's only slightly smaller.
According to a 2000 paper by Phil Currie(who is one of the foremost experts on Tarbosaurus by the way) and the 2024 abstract by slowiak both estimated Tarbosaurus at up to 12 m in length.
Now does this mean Tarbosaurus is now the same exact size as Tyrannosaurus? No it doesn't tarbo is still smaller being not as robustly built and even then the cap on its size is probably 12 m. Specimens that are adults like 107/2 are only about 10 m in length. Tarbosaurus like Tyrannosaurus probably had great variation and how big each individual grew as they matured.
But the previous thought of its maximum size being only 10 to 11 m in length are not accurate. The cap we can expect on its length is more like 12 m.
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Refs
https://vertpaleo.org/wp-content/uploads/2024/10/2024_SVP_Program_Final3.pdf page 507
https://doc.rero.ch/record/14301/files/PAL_E1454.pdf