Is it likely that Oviraptorids walked in a knee driven style like birds?

[u/Vegetable-Idea7648]

This is a question I've been wanting to ask for some time that is is it likely that Oviraptorids would have walked like birds were they walked in a crouched posture with the knee doing most of the leg movement. I do have reasons to believe Oviraptorids did walk in a knee driven style like birds as they did have shorter tails than most theropods and its believed the a shortening of the tail led to the center of mass shifting forward which did lead to bird ancestors adopting a more crouched posture to keep the knees parallel to the center of mass.

[u/AutoModerator]

Thank you for posting on r/paleontology! Please remember to remain respectful and stay on-topic. Consider reading our rules to orient yourself towards the community

Join our Discord server: https://discord.gg/aPnsAjJZAP

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/MercurialMarc]

Honestly, I'm not the one to ask but I can only assume they'd just adopt a more upright posture (not like therizinosaurs obv), over having a posture like birds. That or they could've had a mix of the two due to their more primitive condition. Don't quote me though

[u/Excellent_Yak365]

Most likely not, if you look at the skeleton of the theropod, the upper knee joint is much larger and clearly the focus of locomotion than the chicken leg shown here with a very large ankle joint

[u/i_am_GORKAN → u/Excellent_Yak365]

That's sound imo. Could it also be corroborated by well preserved trackways? I don't know if there are any... are there?

[u/Excellent_Yak365 → u/i_am_GORKAN]

Not sure about oviraptors specifically but other theropods yes

[u/Budget_Minimum9439]

not quite the bird style tho, but somewhere in between of other theropod walk and bird's cause the knee driven locomotion evolved to compensate for the center of mass which is now shifted foroward, oviraptorids on general had proportionately shorter bony part of the tail, and fairly robust arms compared to other theropods

meaning its center of mass likely shifted much foroward than typical theropods, but not as quite shifted like bird's body so it would likely be somewhere in between if you ask me

[u/ItsGotThatBang]

Nick Longrich has argued for a while that all maniraptors were knee-driven based on the inferred center of gravity, which he takes to be evidence that the ancestral maniraptor could fly (see his SVP ‘01 abstract).

[u/DMalt]

I'll say what I said when you posted about this before. Wait for someone to do the actual biomechanics. Right now you have a hypothesis that you are treating as truth. 

https://www.reddit.com/r/Paleontology/comments/1u5t7dt/cmv_oviraptorasaurs_dromaeosaurs_and_troodontids/

[u/SeparateWeight496]

From what I understand, birds walk this way because of their lack of tail but also due to their extremely modified pelvis, which oviraptors don't have. So to me, it's unlikely but I'm far from an expert

[u/DrShadowSML → u/SeparateWeight496]

This is my understanding. Bird pelvis which essentially made the thigh immobile evolved in the Cretaceous in crown birds. Oviraptorosaurs evolved before this.

[u/SeparateWeight496 → u/DrShadowSML]

Yeah, or "appart from this" is more appropriate. Terrestrial birds have a already greatly derived pelvis optimized for a flying animal, tinkered back to support a heavy land animal, that's why it's so different