Triceratops' front legs?

[tyrantqueen]

Found this during a googling session http://www.brantworks.com/triceratops-sprawl.php How possible is it that Triceratops' front legs were sprawled like the author seems to believe?

What's the opinion on this? I thought the sprawling theory had been discarded?

Discuss

[Jetoar]

strange but possible

[ZoPteryx]

It's an interesting problem.  Trackways indicate that ceratopsians feet always contacted the midline and thus they had an upright posture.  But the physical anatomy suggests otherwise.  My current understanding is that the elbows did in fact point outwards, but the legs were still kept columnar.

[0onarcissisto0]

I find that really interesting. Having the front legs sprawled out would certainly offer better balance while moving the head. I imagine wielding a katana sword. My natural instinct would be to widen my stance, knees bent. And I think we all accept that the Triceratops' head played a crucial role in its life, whether for display or defence. So it's plausible that having the front legs positioned this way would offer some type of evolutionary advantage.

[Gryphoceratops]

Fully erect posture in ceratopsids is wrong.  Originally ceratopsids were believed to have been sprawled in the front.  Then Bob Bakker proposed they were more upright like a modern rhino.  This was reinforced by Greg Paul and his illustrations (at the time, his newest book shows them properly sprawled again).  Then it was realized that ceratopsids had a semi-sprawling posture after all due to the way the bones properly fit together.  Its still possible for them to have had walked with their front limbs following a midline, their elbows just would have been angled outwards to the sides more. 

They would have had a more squat posture in the front.  Its not as extreme as a lizard's posture but its not completely upright like most other dinosaurs.  All modern, credible illustrations show this.  Also check out the kaiyodo dinotales models (except the first triceratops) or David Krentz models for a reference.  The Safari's latest Triceratops and Vagaceratops also show this.   

[Simon]

strange but possible

A bit extreme, but elbows out to the side - slightly, with feet under the body makes sense - these animals would not have charged like a bull, but thrust their heads up or to the side and into an unwary predator's torso.  So from a self-defense point of view, its quite logical.

[Patrx]

The sprawl is correct, yes - but the hands aren't facing the right way. Like theropods, ceratopsians lacked the ability to pronate their hands; so the fingers would have faced out to the sides, palms in.

[Gryphoceratops]

This can probably help actually.  You can "view the animated triceratops" its a little less than life-like with the motions but the basic idea is correct. 

http://www.mnh.si.edu/exhibits/triceratops/Triceratopsdigital.htm

[wings]

How possible is it that Triceratops' front legs were sprawled like the author seems to believe?

What's the opinion on this? I thought the sprawling theory had been discarded?

Discuss

Here are some papers http://palaeo-electronica.org/2007_1/step/step.pdf, http://cactus.dixie.edu/jharris/Iron_Springs_Dino_Tracks.pdf and the last one http://download.bioon.com.cn/view/upload/month_1004/20100401_c53c480957da4b866ebd7P3kLPbdcisi.attach.pdf, the first one shows how the bones are fitted on a typical ceratopsian while the second paper shows the hand prints are slightly wider than the footprints (figure 5). The final paper is one of the most recent studies on this very topic.

The sprawl is correct, yes - but the hands aren't facing the right way. Like theropods, ceratopsians lacked the ability to pronate their hands; so the fingers would have faced out to the sides, palms in.

Most of the time yes, the fingers would be facing sideways in this configuration, however this is not always and does not apply to all different groups. Take the Triceratops for example (see last link from above), notice in figure 2C the fourth diagram from the top, the expansion and reorientation of distal end on the radius and  how this allow the first and part of the second digits to shift from its presumably side facing orientation. The main point to remember is that they can't "actively" rotate their hands but by having the lower arm elements to slight overlap (as in some sauropods or hadrosaurs) or reorienting the elements distally it is not a necessity for all the fingers to face to the side.

[tyrantqueen]

Thanks for the opinions everyone, it's given me some food for thought

I guess when I thought of Triceratops' front legs being sprawled, I remembered these old pre renaissance illustrations...



So they were right all along? Just to a less extreme extent?

[DinoToyForum]

I created a poster presentation on this very topic during my masters course in palaeo. I can't remember what I concluded, but I do remember writing a song about it. And an interpretive dance. I never had the guts to perform it though.

[Gryphoceratops]

Thanks for the opinions everyone, it's given me some food for thought

I guess when I thought of Triceratops' front legs being sprawled, I remembered these old pre renaissance illustrations...



So they were right all along? Just to a less extreme extent?

Not as extreme as that illustration but yes, to a lesser extent.  See the sources supplied. 

[wings]

I guess when I thought of Triceratops' front legs being sprawled, I remembered these old pre renaissance illustrations...
So they were right all along? Just to a less extreme extent?

Just to clarify, here is what the current study is proposing (http://blogs.smithsonianmag.com/dinosaur/files/2012/02/Triceratops-posture.jpg, the two top figures, side and front views. Instead of sprawling as far as shown on the bottom two figures which is similar to your "old pre renaissance" illustrations).

[s.foulkes]

YEs this is correct stance elbows slight bend Digit one facing in towards each other the 2nd is pointing straight at frontal view 3rd slight shift to the outside and 4 and 5 not visible front front view and from side view digit 1 not visibale. good job is showing this. thanks.

[Patrx]

^ The Favorite desktop model does a great job with the front limbs, showing the correct, non-pronated hand position, slight sprawl, and reduced fourth/fifth digits. I think the model does show nails on those digits, though, which is currently regarded as innacurate.

[CityRaptor]

The current depiction seems to me far closer to the depictions Bakker made than to those Pre-Renaissance.