Sleeping giant sauropods

[Vladimír Socha]

Good day!

I'm wondering, what was the anatomical and physiological posture of sleeping giant sauropods (say, those weighing over 50 tonnes)? I cannot imagine how could they stand up from "lying" position - or for that matter, how would they be able to lie down and not kill themselves in the process - but if they were standing during their sleep, what would be likely position of their necks and heads? Surely not lowered to the ground, as that would make them extremely vulnerable to theropod predators and other carnivores. Was this topic already debated and is there any plausible hypothesis? I don't believe that, e.g. Dr. Taylor never wondered about this also :-) Thank you for your thoughts, in advance! VS.

References:

Choy, D. S.; Altman, P. (1992). The cardiovascular system of barosaurus: an educated guess. Lancet. 340 (8818): 534–6.

Stevens, K. A.; Parrish, J. M. (1999). Neck posture and feeding habits of two Jurassic sauropod dinosaurs. Science. 284 (5415): 798–800.

Seymour, R. S. (2009). Raising the sauropod neck: it costs more to get less. Biol. Lett. 5 (3): 317–319.

Taylor, M. P.; Wedel, M. J.; Naish, D. (2009). Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54 (2): 213 – 220.

Cobley, M. J.; Rayfield, E. J.; Barrett, P. M. (2013). Inter-Vertebral Flexibility of the Ostrich Neck: Implications for Estimating Sauropod Neck Flexibility. PLOS ONE. 8 (8): e72187.

[Mike Taylor]

Hi, Vladimir. Matt Wedel (who I am CCing) and I have certainly thought about this a lot, as has Darren Naish. But none of us has come up with any solid lines of thought, and to the best of my knowledge neither has anyone else. It's a problem crying out for study, but also crying out for a good way to address the problem.

-- Mike.

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[Stephen Poropat]

There’s a wonderful old book “Rhinos Belong to Everybody” by Bernhard Grzimek that shows a giraffe head and neck stuck in the branches of a tree, with a leopard in attendance IIRC. Cannot remember the caption / explanation offhand but the lower portion of the giraffe had been detached and eaten. How the giraffe came to be stuck was not clear.

For sauropods, resting the head in the crook of a branch might have been an option (albeit a potentially dangerous one).

For comparison I did a quick online search about giraffe sleeping habits (far from authoritative), which suggests that a) they mostly sleep standing up with neck raised, b) they sleep relatively little, and c) even when not standing they tend to keep their necks up.

Dr Stephen F. Poropat

Deputy Director

Western Australian Organic and Isotope Geochemistry Centre

School of Earth and Planetary Sciences

Curtin University

Bentley, Western Australia

Australia 6102

https://stephenporopat.weebly.com/

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[Thomas Richard Holtz]

During the production of the new Walking with Dinosaurs, trying to figure out a realistic way to get the Lusotitan to stand back up was a challenge. We tried a number of options, and went with the one that looked least impossible.

Thomas R. Holtz, Jr.
Email: tho...@umd.edu         Phone: 301-405-4084
Principal Lecturer, Vertebrate Paleontology

Office: CHEM 1225B, 8051 Regents Dr., College Park MD 20742

Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/

Phone: 301-405-6965
Fax: 301-314-9661              

Faculty Director, Science & Global Change Program, College Park Scholars

Office: Centreville 1216, 4243 Valley Dr., College Park MD 20742
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address: 

                        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117

                        8000 Regents Drive
                        University of Maryland
                        College Park, MD 20742-4211 USA

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[mkir...@gmail.com]

[Gregory Paul]

Oh that's easy enough. A time machine, like duh. 

GSPaul

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[Stephen Poropat]

My memory is fallible! Thanks for clarifying that for us Mary.

Dr Stephen F. Poropat

Deputy Director

Western Australian Organic and Isotope Geochemistry Centre

School of Earth and Planetary Sciences

Curtin University

Bentley, Western Australia

Australia 6102

https://stephenporopat.weebly.com/

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[Vladimír Socha]

OK, I thought there is at least some working hypothesis already. I guess the most plausible answear is sleeping in the standing position, just like almost all big animals today (elephants have a really bad time trying to stand up, let alone ten times heavier sauropods). At least T. rex seems to give a better clue in the form of its huge pubic bone, which was “basically a kickstand” to hold it up while the monstrous predator was snoozing (as Scott Persons put it). Anyway, does the idea of supportive role of its small, but relatively strong arms when rising from the prone position still hold? Is any new research conducted on the T. rex ichnofossils from the Raton Basin (briefly described in 2021) that perhaps show this behavior? Thank you! VS.

References:

Arp, D. (2020). Developing an Assessment to Evaluate Tyrannosaurus rex Forelimb Use Cases. Biosis: Biological Systems. 1 (3): 102–108.

Caneer, T.; Moklestad, T.; Lucas, S. G. (2021). Tracks in the Upper Cretaceous of the Raton Basin possibly show tyrannosaurid rising from a prone position. In: Lucas, S. G., Hunt, A. P. & Lichtig, A. J., 2021, Fossil Record 7. New Mexico Museum of Natural History and Science Bulletin. 82: 29–37.

Padian, K. (2022). Why tyrannosaurid forelimbs were so short: An integrative hypothesis. Acta Palaeontologica Polonica. 67 (1): 63–76.

Dne čtvrtek 14. srpna 2025 v 1:23:26 UTC+2 uživatel Mike Taylor napsal:

[Richard W. Travsky]

 

What issues would accompany a rex (and probably other large theropod types) leaning over to drink? Just off hand it seems there would be some overlap in how it was accomplished.