The Allosauroidea thread (allosaurs, carcharodontosaurs and kin)

Since the new spinosaur has gotten everybody in the mood for some giant carnivore discussion, I thought you might enjoy this piece by Dinosaur Tracking Blog which chronicles the family history of another high spined theropod, Acrocanthosaurus atokensis. Surprisingly, it's not closely related to the spinosaurs at all, but their 'rivals' the carcharodontosaurs (who also feature prominently in the aforementioned thread).


Image by L.D. Austin

The bigest one found was 38 feet (about 11 and a half metres) with a skull over four feet in lenght and an overall similar build to the giant carcharodontosaurs, but not quite as massive in build. It was roughly the same size as a T. rex, although the largest Tyrannosaurus specimens were marginally bigger.

Rubecula wrote: »

But it has a friendly smile:pac:

The same friendly smile you see in crocodiles today...

Another article on the same find. The journalists are calling Acrocanthosaurus "T-Rex cousin". o-O

http://abcnews.go.com/Technology/dinosaur-tracks-found-arkansas-cover-football-fields-made/story?id=14690741

Galvasean wrote: »

The bastardization of every theropod as a 'T. rex cousin' continues....

T-Rex must be tired of so many sudden relatives...

Galvasean wrote: »

It's like when you win the lotto... (I'm told)

Indeed...

New theropod teeth from the latest Cretaceous (Maastritchian) of Brazil have been found and analyzed. Some of them seem to belong to abelisaurs, but the most interesting ones seem to be from carcharodontosaurs, which were supossed to have went extinct long before the late Cretaceous.
Of course, being just teeth, we can´t be sure- they may belong to some other kind of theropod that developed similar diet habits/teeth, or even to crocodilians. When the blade-like, serrated teeth sebecids were found for the first time, scientists believed non-avian theropods had made it to the Eocene in South America, because the teeth were so similar.

EDIT: A later study found that these teeth may belong to abelisaurids after all.

I have to admit it's an exciting idea, tho- to have T. rex and carcharodontosaurs walking the Earth at the same time, albeit in different places.

http://ojs.c3sl.ufpr.br/ojs2/index.php/rbg/article/view/21309

Galvasean wrote: »

I guess we may soon be throwing out the conventional logic that carcharodontosaurs were outcompeted by smaller, 'more advanced' theropods. Perhaps another cases of 'lack of evidence =/= evidence of absence'.

I think it makes sense that if carcharodontosaurs were specialized sauropod-hunters, and sauropods made it to the very end, there is no reason to suposse that carcharodontosaurus wouldn´t make it along with them. Perhaps they simply became rarer/less diverse, but then, same happened with tyrannosaurs in North America it seems.

It seems there's also a maxilla of the late Cretaceous Brazilian carcharodontosaur, not only teeth. It was quite a bit smaller than its earlier relatives; its skull was only 80 cms long.

Not yet, to my knowledge.

This culture of calling everything a cousin of T. rex is getting a little bit grating...

But hey at least they follow up with:
"Many people think of Allosaurus as a smaller and earlier version of T. rex, but our engineering analyses show that they were very different predators.""

Rubecula wrote: »

It is bloody annoying this "everything is related to T-rex" attitude. I think we are predators too so we must be related to T-Rex as well. "ROARRRRRRRRRR"

Guess we are if we consider we are all descended from a same common ancestor... but then why not start calling potatoes T-Rex relatives while we're at it?

PS- Regarding the "Many people think of Allosaurus as a smaller and earlier version of T. rex, but our engineering analyses show that they were very different predators.""part, I figured that out at age 3 and I didn´t need engineering analyses... or a phD :pac:

Ties in nicely with my theory of how sparrowhawks are great to watch if one wants to form ideas about theropods. Much better example than a falcon as Sparrowhawks will hunt on foot as well as on the wing making them a much more rounded ambush predator

Some on here may remember me rambling on about it a year or so ago.



Sparrowhawk: The T-rex Allosaurus of back gardens. :P

I like falcons

Apparently they didn´t suffer much from bone abnormalities but they did suffer constant injury due to their lifestyle. Nothing unexpected I suposse:

http://www.ploscollections.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0063409;jsessionid=9FC937EF0D16A51EA761B589DBCD56BA

I think they both are

That's because the smaller one is a juvenile:

I must confess I don´t see anything strange with it

Siats meekerorum, a new giant theropod from North America.

It was a neovenatorid. The remains of a 9 meter long individual were found in 2008, but, as usual, its a juvenile, suggesting it was as big as Acrocanthosaurus, and potentially the second or third largest carnivorous dino ever found in North America. This creature would've been the top predator of its day; only after its fall would tyrannosaurids rise as the new superpredators.

http://www.ibtimes.com/new-dinosaur-siats-meekerorum-discovered-kept-early-tyrannosaurs-check-photo-1482478

I think its the perspective, but earlier carcharodontosaurs did have huge heads... Im not sure if the skull was found

Evidence of Allosaurus killed by Stegosaurus. You may already have read this one:

http://westerndigs.org/allosaurus-died-from-stegosaur-spike-to-the-crotch-wyoming-fossil-shows/

Juvenile Allosaurus auctioned, fails to sell.

http://www.dailymail.co.uk/sciencetech/article-3333473/Meet-Little-Al-rare-skeleton-baby-Allosaurus-teeth-like-steak-knives-fetch-500-000-auction.html

Problem with specimens such as this, which are owned by private parties, is that they're usually unavailable for study, meaning most questions are likely to go unanswered until it goes to a museum or some sort of scientific institution.

I had never heard of Little Al before this.