It's an interesting theory, yet I still believe Megaraptorids were different.

Like I said, it is a theory ;)

Also, if megaraptorids were tyrannosaurs, then Siats would be one of the largest tyrannosaurs. In fact, it might explain how tyrannosaurs took over North America from the allosaurs/carcharodontosaurs of the Jurassic/Early Cretaceous. Allosaurus rules, followed by Acrocanthosaurus, then the tyrannosaurs take over in the form of Siats, with T.rex finally coming next. Just a thought ;)

That's definetly an eye brow raiser, could be possible.

Let's just see what history has instored.

Fossils however need more correlation tho

Indeed. I don't know specifics, I've just heard the idea thrown around there and, technically, it makes a little sense. Basal tyrannosaurs have been found in the south, so southern tyrannosaurs aren't unheard of. And as I said earlier, many primitive tyrannosaurs have a lot in common with the megaraptorids.

Hmm...sounds very interesting, I will conduct further research on this.

I want to see if this adds up to their evolutionary branch. :)

Something interesting:

Abstract
 Megaraptorids are a group of predatory dinosaurs that inhabited
 Gondwana from Cenomanian to Santonian times (Late Cretaceous).
Phylogenetic relationships of megaraptorids have been matter of recent
 debate, being alternatively interpreted as basal coelurosaurs, carcharodontosaurian allosauroids, megalosauroids, and basal
 tyrannosauroids. One of the main reasons for such different
 interpretations is the incomplete nature of most available
 megaraptorid skeletons and, in particular, the scarce information
 about their cranial anatomy. Here we describe a partially preserved
 skeleton of a juvenile specimen of Megaraptor namunhuaiquii that
 provides substantial new information about the cranial morphology of
 this Patagonian taxon. The specimen comes from the Upper Cretaceous
 (Turonian–Coniacian) of the Portezuelo Formation, northwestern
 Patagonia, Argentina. The anatomy of the new specimen bolsters the
 recently proposed hypothesis that megaraptorids are nested within
Coelurosauria, and possibly within Tyrannosauroidea. The most relevant
 features that megaraptorans share with tyrannosauroids include several
 foramina on the premaxillary body, extremely long and straight
 prenarial process of the premaxilla, incisiviform premaxillary teeth
 with a D-shaped cross-section, and cranially expanded supratemporal
 fossae separated from each other by a sharp sagittal median crest on
 frontals, which was presumably extended caudally above the parietals
 (not preserved). Information gathered from the present specimen allows
 to make for the first time a reconstruction of the skull of Megaraptor
 and hypothesize about evolutionary trends within Tyrannosauroidea.   

Damn paper's paywalled, but if anyone thinks they can find it, here's the citation

Juan D. Porfiri, Fernando E. Novas, Jorge O. Calvo, Federico L.
 Agnolín, Martín D. Ezcurra & Ignacio A. Cerda (2014)
 Juvenile specimen of Megaraptor (Dinosauria, Theropoda) sheds light
 about tyrannosauroid radiation.

Anyway, i guess this shook things up quite a bit. Here's what the 
megaraptora family tree looks like nowadays

However, we must keep in mind the fact that Tyrannosauroids
 aren't Tyrannosaurids.
For example:

Went off-page there; here's the link:
http://en.wikipedia.org/wiki/Tyrannosauroidea

Siats would, theoretically, be the largest basal
 Tyrannosauroid based on these cladograms, if they're proven to be correct. 
Interesting stuff considering the time frame it occupied..

Nice find there Carnosaur. Yes, tyrannosauroids aren't really closely related to T.rex, but are the earliest members of the group as a whole. Very interesting stuff overall. It seems that tyrannosaurs(being general here) may have been apex predators just about everywhere in the Cretaceous.

i think that it is possible, but don't just look from the outside, this conclusion is not cocreat untill the scientist test the DNA of a megaraptorids and a tyrannosauroid

REX FAN 684 - What a fascinating theory! I'd actually never heard of this bit of speculation, however, it does indeed seem to hold water! How very neat! :)

Weren't Siats smaller than T.Rex?

Yeah, T.rex was bigger. Why?

Nice post, I personally think that Megaraptorids are Tyrannosauroids. About Siats, I don't agree with that size comparison to T-Rex. In terms of length, Siats was up there with T-Rex at about 40 feet. In terms of weight, T-Rex probably weighed twice as much as Siats.

Well, technically, that size comparison is of the "juvenile" Siats specimen, so it is accurate as far as length goes. The holotype is 9 meters, but the adult size is probably around 11-12 meters.

Glad you like the post :)