Pathetic vestigial organ or integral part of fearsome predator?

November 25, 2014 9:36 AM

In this paper, we examine a first-year torque and angular acceleration problem to address a possible use of the forelimbs of Tyrannosaurus rex. A 1/40th-scale model is brought to the classroom to introduce the students to the quandary: given that the forelimbs of T. rex were too short to reach its mouth, what function did the forelimbs serve? This issue crosses several scientific disciplines including paleontology, ecology, and physics, making it a great starting point for thinking “outside the box..." Lipkin and Carpenter have suggested that the forelimbs were used to hold a struggling victim (which had not been dispatched with the first bite) while the final, lethal bite was applied. If that is the case, then the forelimbs must be capable of large angular accelerations α in order to grab the animal attempting to escape. The concepts of the typical first-year physics course are sufficient to test this hypothesis... Naturally, student love solving any problem related to Tyrannosaurus rex.
posted by ChuraChura (19 comments total)

Argh, I missed a few.
posted by ChuraChura at 9:45 AM on November 25, 2014 [1 favorite]

There was a Discovery Channel/Nat Geo/Animal Planet program years ago whose thesis was that the Tyrannosaur forelimbs were used during mating to stimulate during coitus. Anyone else remember this?
posted by Renoroc at 10:24 AM on November 25, 2014

Speaking of problems related to Tyrannosaurus Rex, the internet today introduced me to the trailer for Jurassic World.

Why anyone (including Chris Pratt) thought this was a good idea is beyond me.
posted by sparklemotion at 10:39 AM on November 25, 2014

On not following all the links in the comments: I see you are one step ahead of me, ChuraChura. Life finds a way.
posted by sparklemotion at 10:40 AM on November 25, 2014

Someone had fun with this display.
posted by empath at 10:48 AM on November 25, 2014 [1 favorite]

Why anyone (including Chris Pratt) thought this was a good idea is beyond me.

Dinosaurs biting people is always a good idea.

MUTANT dinosaurs biting people is always an excellent idea.
posted by ROU_Xenophobe at 10:58 AM on November 25, 2014 [2 favorites]

I'm going with toothpicks. Also, playing a banjo.
posted by mule98J at 11:19 AM on November 25, 2014 [1 favorite]

MUTANT dinosaurs biting people is always an excellent idea.

Watch your flatscan fear-mongering, bub.
posted by entropicamericana at 11:26 AM on November 25, 2014

Dinosaurs biting people is always a good idea.

MUTANT dinosaurs biting people is always an excellent idea.

I love dinosaurs, and I love cheesy disaster movies and I had NO IDEA a new Jurassic Park movie was coming. that trailer has me excited!!!!
posted by supermedusa at 11:28 AM on November 25, 2014

T-Rex Trying...
posted by gottabefunky at 11:45 AM on November 25, 2014 [2 favorites]

I remember reading years ago a postulation that T. rex used its forelimbs to raise itself off of the ground after sleep. The authors believed that the muscles attached to the forelimbs were actually quite strong.
posted by frodisaur at 1:04 PM on November 25, 2014

Hey! I'm trying to pass the potatoes! ...
posted by obscure simpsons reference at 1:08 PM on November 25, 2014 [2 favorites]

As someone with remarkably short arms and a fondness for biting people affectionately (what, I'm just operationalizing "you're so cute I could eat you up!") I look forward to further scientific exploration of what evolutionary purpose my weak and foreshortened arms are supposed to serve. I can confirm that my selfies often feature my shoulder.
posted by spamandkimchi at 1:20 PM on November 25, 2014 [2 favorites]

Oh hooray, an excuse to mention my very favorite amateur science theory: behold Treeosaur! (previously)

This guy believes that T. rex's little bitty arms were one of many adaptations that it evolved to allow it to stand hunt from trees in this posture. His argument is more concerned with its vision and spine/jaw morphology, but the arms allow the T. rex to cling to the tree without giving itself away.

I love literally everything about that website, but I like this image most of all.

I have no clue how plausible his conclusions are, but I love the way he went about building his argument, and I love his incredible enthusiasm for answering this question. Three cheers for the Treeosaur guy!
posted by dialetheia at 2:34 PM on November 25, 2014 [7 favorites]

This seems as good of time as any to post my favorite 51 seconds of tv. Behold a metal T-rex head destroying a mini cooper.
posted by Gygesringtone at 3:47 PM on November 25, 2014

Why anyone (including Chris Pratt) thought this was a good idea is beyond me.

If someone drove up to my house with a dump truck full of money and said "No-sword, you can keep all this money, but in exchange you have to let us make a movie in which you ride a motorcycle at the head of a pack of velociraptors on a thrilling chase through the forest," well, I don't think I would say no either.
posted by No-sword at 5:03 PM on November 25, 2014 [11 favorites]

Maybe they were so that in the frenzy, they didn't bite their own arms, only the prey extending above the hands. Makes sense to me. I don't often bite my fork but then again my dinner is usually still. Do you suppose they spit out the heads then?
posted by Oyéah at 5:11 PM on November 25, 2014

I expect that the t-rex was part of a symbiotic pair of organisms similar to the Geefle and the Gonk.
posted by ROU_Xenophobe at 5:42 PM on November 25, 2014 [1 favorite]

And it has monorails.
posted by mikelieman at 8:56 PM on November 28, 2014