The Tyrannosaur Thread- Anything T. rex or tyrannosaurid related

Carpenter wrote: »

I have 1 in my back garden (But it is asleep now):D

Mine chases cats.

Good article on it here (yes, Fox News can be surprisingly good with their palaeontology stories).
I wonder how closely related to Tarbosaurus this new dinosaur (it's name hasn't beeen formally given yet, so damed if I'm typing it unless absolutely necessary!)? It appears to be a couple of million years older. Perhaps it's a possible ancestor?

In that picture it looks like a T.rex in a clown suit to entertain the kids.

Can it tell jokes? No
Can it juggle balls? No
But it keeps the little blighters quiet!

:D:D

Whilst debate is ongoing as to whether or not Nanotyrannus of Cretaceous North America is a juvenile Tyrannosaurus or not, a similar debate has emerged in relation to two Asian tyrannosaurs.
Raptorex kreigsteini was believed to be a 'primitive' small bodied ancestor type to the giant tyrannosaurs of the late Cretaceous. However, a new paper (available for free at PLoS ONE) questions this conclusion. It appears that Raptorex is almost certainly a juvenile of something larger, possibly Tarbosaurus. Another idea is that it does represent it's own valid genus, but reports of it being adult or close to adult age look to be erroneous.

Rubecula wrote: »

Surely if it is a primitive ancestor it will be a lot older than a bigger creature? Doesn't it's age give it away? If it is about the same age it is more likely to be a young 'un. Mind you being the same age does not preclude it being a different species, just that it is unlikely to be an ancestor species.

The problem with Raptorex is that the one specimen we have was bought from a fossil dealer. As such it's place of origin is not entirely certain, calling into dispute as to what age it lived in.

Looks like it's on its way back to Mongolia:
http://blogs.smithsonianmag.com/dinosaur/2012/06/release-the-tarbosaurus/

Galvasean wrote: »

I still can't get my head around how it managed to stay preserved for so long.

Yeah it's crazy. I read the paper last night so I'll try give a summary of their theory, though I'll probably get it a bit of it mixed up.

The 'cells' found were ostecytes or bone cells. They were isolated by dissolving the bone and then using a few treatments (e.g. centrifugation). When I first heard about this I imagined a palaeontologist cracking open a bone and finding some goo in the cavity inside, from reading the paper it seems that it is basically the cell 'skeletons' (e.g. structural proteins such as actin) that have been preserved inside the structure of the bones.

The major line of evidence that these are dinosaur cells and not anything else is that antibodies from ostriches will bind to them. This didn't happen in the alligator and bacteria controls.

The researchers propose that the the location deep within the bone is what protects the cells from the rapid decay we would typically imagine. Osteocytes, they claim, are especially long lived and would not exhibit the same rate of turn over as other cell types such as skin or intestinal cells, perhaps lasting the entire lifespan of the animal (and beyond).

The location of the cells also protects them from degradation due to environmental conditions as well as breakdown by bacteria. The researches also posit that they are protected from the organisms own systems which breakdown damaged or diseased cells.

Finally the researchers suggest that the releases of high levels of iron from the breakdown of hemoglobin acts to 'fix' the cells (i.e. preserve them). I always thought that in order to preserve cells and tissue for extended periods of time that the water must be removed an replaced with some other preserving agent. I don't think the researchers address this but I may be wrong.

It's certainly an incredible discovery if it's true and of immense scientific value. I look forward to what other researchers write about this.

McG wrote: »

sadly not, recent studies suggest DNA has a half life of 521 years so no hope of getting any readable DNA

http://www.nature.com/news/dna-has-a-521-year-half-life-1.11555

Weird, the New Scientist story on this same research gives a half like of ~150,000 years. http://www.newscientist.com/article/dn22359-dnas-halflife-identified-using-fossil-bones.html

Shows how important it is to look at the primary literature I suppose.

The T. rex soft tissue paper claims that DNA was found in the dinosaur 'cells'. Though it has been significantly degraded.

Just a bit of 'armless research methinks.

Interesting, and slightly OT. What about the Elgin Marbles?

Or possibly a Tyrannosaurus bataar, depending on which palaeontologists you listen to. FWIW, nowhere in the linked article does it say, "T. rex".

Adam Khor wrote: »

Yeah, that was my point. It seems, tho, that Tarbosaurus may actually be more related to Alioramus than to Tyrannosaurus; sort of convergent evolution between two different tyrannosaur linneages. If so, we can kiss "Tyrannosaurus bataar" goodbye and T-Rex goes back to being the only known species of its genus...

That was something that escaped me totally until you pointed it out Adam. Thank you for that. Convergent evolution must have occurred back then, it occurs today. I am now feeling quite intrigued. (And foolish for missing the point)