Giant dinosaur speed discussion thread

[Infinity Blade]

So, does this quote from Bakker about Tyrannosaurus in The Dinosaur Heresies (which hasn't aged well in a number of respects, anyway) still hold water?

A quite different approach to the question of dinosaur speed is provided by calculating the maximum strength of the bone shafts of the limbs. Legs do break in nature, and evolution usually outfits a species with bone shafts strong enough to withstand the highest strains imposed when muscles contract. Rhinos have relatively stout, thick-shafted legs. Elephants feature a more spindly design. To measure the shaft strength of dinosaur limbs, I constructed scale models in clay of the life appearance of various species. I then calculated the live weight by measuring the volume of the model (most land animals are a little less dense than water, so live weight is about 95 percent of the body's volume in water). Brontosaurs and stegosaurs were somewhat thin-thighed, and in cross section their bones are about as thick as we would expect in an elephant of similar size. But Triceratops, Tyrannosaurus, and the other predators were much more massively shafted, far stronger in girth of bone, and these dinosaurs could exert positively prodigious force through their limbs without fear of fracture.

Edit: if it was this light, maybe? I'm still not sure.

Alexander (1989) estimated that the type Tyrannosaurus femur was too weak for a fast gait. Estimated body mass was 8000 kg, but this was based on an inaccurate toy model. A technical restoration of the type specimen cannot distinguish its mass from the similar sized and more complete AMNH 5207, which is estimated via a careful skeletal restoration and model to mass 5700 kg (Paul 1988, 1987). The type femur is preserved intact, and is therefore more robust than that of MOR 555 (Fig. 6). At 5700 kg, femur strength is similar to that of an ornithomimid (Farlow, 1990). This suggests that giant tyrannosaur limb bones were as well able to withstand running forces as those of their smaller relatives.

Source: Paul, G.S. (1998). Limb design, function and running performance in ostrich-mimics and tyrannosaurs. Gaia, 257-270.

[Infinity Blade]

theropod posted a useful chart r.e. the maximum compressive strength of bone in another thread, and I thought it might be useful for a post here.

theworldofanimals.proboards.com/post/43240

The only speed estimate of their own that Sellers et al. (2017) explicitly mention for Tyrannosaurus is 7.7 m/s for high stress limit conditions (i.e. >200 MPa). They say lowering this stress limit has little effect on speed until it becomes lower than 150 MPa. If this chart is anything to go by and we assume a maximum compressive strength limit of ~165 MPa or so, then we can say 7.7 m/s is about right as a top speed. Well, at least from their methods. I still have the same issues I've mentioned before with their paper (i.e. potential mass overestimate, limbs are oriented too straight, lack of shock-absorbing soft tissue that they mention themselves, and potentially Stan just having been found with abnormally gracile femora for a Tyrannosaurus of its size->; taphonomic distortion perhaps?).

Edit: indeed, bone has a compressive strength of 170 MPa.

Source: Schmidt-Nielsen, Knut (1984). Scaling: Why Is Animal Size So Important?. Cambridge: Cambridge University Press. p. 6. ISBN 978-0-521-31987-4.

[Infinity Blade]

Oct 13, 2018 3:02:26 GMT 5 Infinity Blade said:

Alexander (1989) estimated that the type Tyrannosaurus femur was too weak for a fast gait. Estimated body mass was 8000 kg, but this was based on an inaccurate toy model. A technical restoration of the type specimen cannot distinguish its mass from the similar sized and more complete AMNH 5207, which is estimated via a careful skeletal restoration and model to mass 5700 kg (Paul 1988, 1987). The type femur is preserved intact, and is therefore more robust than that of MOR 555 (Fig. 6). At 5700 kg, femur strength is similar to that of an ornithomimid (Farlow, 1990). This suggests that giant tyrannosaur limb bones were as well able to withstand running forces as those of their smaller relatives.

Source: Paul, G.S. (1998). Limb design, function and running performance in ostrich-mimics and tyrannosaurs. Gaia, 257-270.

I just realized that this is contingent upon what mass estimate you believe for the Tyrannosaurus specimen in question (since Paul mentioned the type specimen, I'm guessing CM 9380). In light of the recent discussion on theropod density, though, I'm not sure what to believe anymore, particularly with CM 9380. Any ideas?



^That's from Farlow (1990)->, btw.

Compare this to strength indices of a 2.5t L. africana individual (Alexander, 1985). 11 for the humerus, 7 for the femur, and 9 for the tibia. Although a strength index of 13 is still almost 20% greater than that for the elephant humerus, I wonder if it may be more worth focusing on the elephant's hindlimbs. They are supposedly almost entirely responsible for propulsion.

The carrying forces recorded by the force platform indicate how the weight is distributed between the front and hind limbs. In a standing horse the front limbs carry about 55% of the horse’s weight, the hind limbs about 45%. However in the elephant weights are on the forelimb (Leleu, et al., 2005). The hindlimbs become almost entirely responsible for providing propulsion. The front limbs lose most of their propulsive thrust instead they provide more braking, which is used in combination with the carrying force of the front limbs to push the shoulders and forehand upwards and backwards (Sissons, et al., 1975).

Tefera, 2012

[Infinity Blade]

I found a paper titled Evolution of Locomotor Trends in Extinct Terrestrial Giants Affected by Body Mass (Kokshenev & Christiansen, 2011)-> that seems to do with the topic here. What I think I can gather is that their data suggests that the giant theropods sampled (e.g. Tyrannosaurus and Giganotosaurus) were anatomically well-adapted to running modes while sauropods were restricted to a walking gait (not wholly surprising).

If I'm interpreting its tables and figures correctly, table 1 along with figures 2, 3, and 4 seem to imply that theropods are indeed better adapted to faster locomotion than proboscideans (which in turn seem to be capable of faster locomotion than giant sauropods, as slow as proboscideans may be in absolute terms). I think Fig. 2 is suggesting the theropods to have higher limb bending stress indicators than the graviportal proboscideans and sauropods.

Am I right?

I'm sorry if it feels like I'm forcing this thread with my own inquiry, this is just a topic where I've gained somewhat of an interest in and have questions about that I would like to see elucidated.

[theropod]

What infinity posted on recommended literature is of interest to this thread:

Limb length, cursoriality and speed have long been areas of significant interest in theropod paleobiology, since locomotory capacity, especially running ability, is critical in the pursuit of prey and to avoid becoming prey. The impact of allometry on running ability, and the limiting effect of large body size, are aspects that are traditionally overlooked. Since several different non-avian theropod lineages have each independently evolved body sizes greater than any known terrestrial carnivorous mammal, ~1000kg or more, the effect that such large mass has on movement ability and energetics is an area with significant implications for Mesozoic paleoecology. Here, using expansive datasets that incorporate several different metrics to estimate body size, limb length and running speed, we calculate the effects of allometry on running ability. We test traditional metrics used to evaluate cursoriality in non-avian theropods such as distal limb length, relative hindlimb length, and compare the energetic cost savings of relative hindlimb elongation between members of the Tyrannosauridae and more basal megacarnivores such as Allosauroidea or Ceratosauridae. We find that once the limiting effects of body size increase is incorporated there is no significant correlation to top speed between any of the commonly used metrics, including the newly suggested distal limb index (Tibia + Metatarsus/ Femur length). The data also shows a significant split between large and small bodied theropods in terms of maximizing running potential suggesting two distinct strategies for promoting limb elongation based on the organisms’ size. For small and medium sized theropods increased leg length seems to correlate with a desire to increase top speed while amongst larger taxa it corresponds more closely to energetic efficiency and reducing foraging costs. We also find, using 3D volumetric mass estimates, that the Tyrannosauridae show significant cost of transport savings compared to more basal clades, indicating reduced energy expenditures during foraging and likely reduced need for hunting forays. This suggests that amongst theropods, hindlimb evolution was not dictated by one particular strategy. Amongst smaller bodied taxa the competing pressures of being both a predator and a prey item dominant while larger ones, freed from predation pressure, seek to maximize foraging ability. We also discuss the implications both for interactions amongst specific clades and Mesozoic paleobiology and paleoecological reconstructions as a whole.

Dececchi TA, Mloszewska AM, Holtz TR Jr, Habib MB, Larsson HCE (2020) The fast and the frugal: Divergent locomotory strategies drive limb lengthening in theropod dinosaurs. PLoS ONE 15(5): e0223698. doi:10.1371/journal.pone.0223698
journals.plos.org/plosone/article?id=10.1371/journal.pone.0223698

[Infinity Blade]

Yeah, I posted it in the recommended literature thread, but no real worries.

[all]

My guess is about 30-40 km an hour for T Rex. maybe a little less but I wouldn't be surprised if he could clock as much as 35 km maybe even more. I haven't done enough research to guarantee it but that would sound about right

but if we are talking speed of Theropods why are we mentioning only T-Rex and others like him
why not include smaller theropods like lets say Utahraptor.  Which could probably clock close to 90 km/h for short distance and 60 km/h for little bit longer like a modern ostrich.

[Infinity Blade]

Apparently Bakker noted this back in 2002. The thing in bold particularly stuck out to me.

SPEED IN TYRANNOSAURS
BAKKER, Robert, Wyoming Dinosaur International Society, 1447 Sumac Ave., Boulder, CO 80304.

Competing theories about speed in giant theropods can be tested with combinations of scaling parameters, Recent analogues, and fossil footprints. Models based on elephant analogues are inferior to those based on rhinos, because all theropods agree with all rhinos in possessing: high flexure at all joints, permitting elastic rebound during fast runs; large cnemial crest, affording high leverage for knee extension during rebound; long, compact metatarsus with large calcaneum tuber or hypotarsus tuber, providing high leverage for ankle extension and long ankle-segment contribution to the stroke. For a given body mass, giant theropods possess greater strength to resist bending in the limbs than do elephants because the cross-section of the femur is greater than that of the elephant femur and humerus combined.

Tyrannosaurid footprints from the Lance Formation at Glenrock, Wyoming, show a cruising speed as high or higher than that of small theropods. There is no evidence that large theropods were slower, on average, than small theropods. Large theropod footprint speeds are much higher than those of mammoths and mastodons. Tyrannosaurs were not bipedal elephants.

www.miketaylor.org.uk/tmp/svp-abstracts/SVP%202002%20abstracts.pdf?fbclid=IwAR084DSrsX2SGFr9VppSHnrFM4mQ_CpMys9CDHXDzucGn3Rz7VIkRBt-Y4A

[Infinity Blade]

Tyrannosaurid tracks reveal an increase in foot robusticity with ontogeny, going from being suited to cursorial to weight bearing habits.

www.tandfonline.com/doi/full/10.1080/02724634.2021.1878201

[Infinity Blade]

The paucity of extant giant terrestrial tetrapods challenges us to look into Deep Time, and integrate these inferences with neontological data to formulate a comprehensive body of knowledge for evolutionary biomechanics. But gigantism is rare, and often short-lived in geological time scales. Larger taxa face greater risks of extinction during rapid environmental changes (Bakker, 1980; Janis and Carrano, 1992; Payne et al., 2009). For this reason, Dick and Clemente (2017) considered gigantism ‘maladaptive’, but this risks the orthogenetic or teleological thinking that has long plagued the study of land giants (Cope, 1896; Osborn, 1922). The evolutionary trade-offs with gigantism (e.g. offence/defence, efficient locomotion or resource-domination versus slow reproduction and evolution) will be highly environment-specific, as exemplified by the >170 million years of evolutionary history in giant dinosaurs, which only the freak accident of an extraterrestrial impact ended. Rhinoceroses alone reveal that, even at giant sizes, surprising locomotor performance can persist, and extinct lineages hint that this has evolved repeatedly – the ‘elephant solution’ is not the only solution for land giants. McPhee et al. (2018) described fragmentary remains of a giant early-Jurassic sauropodomorph and speculated, on the basis of its robust forelimb bones, that it adopted more crouched forelimb poses (∼low EMA) relative to giant sauropods with uncontroversially columnar forelimbs (higher EMA). Although the robust bones might have been specializations related to feeding or other behaviours, and need further investigation in a biomechanical context, they remind us that fossil taxa could have deviated from prevalent patterns in extant giants. Perhaps giant bipedal theropods such as Tyrannosaurus could achieve brief aerial phases or a bouncing ‘grounded run’ (Gatesy et al., 2009; Sellers et al., 2017). But elephants also reveal that their ‘solution’ is not so simple as merely sedate walking, either. A nuanced approach to the evolutionary biomechanics of land giants is important for unravelling the perplexing mysteries that they continue to pose.

journals.biologists.com/jeb/article/224/11/jeb217463/269062/The-evolutionary-biomechanics-of-locomotor

[Infinity Blade]

Not about running speed, but walking speed.

Comments on “A tyrannosaur trackway at Glenrock, Lance Formation (Maastrichtian), Wyoming” (Smith et al., Cretaceous Research, v. 61, pp. 1–4, 2016)

The paper by Smith et al. (2016) included speed calculations performed from a tyrannosaur trackway at Glenrock, Lance Formation, Wyoming. These authors concluded that tyrannosaurs walked in speeds similar to those obtained for other large theropod, but faster than proposed for hadrosaurids, a potential prey. However, the calculations performed by Smith et al. (2016) suffered from methodological and computational errors, which greatly affected the reported results. Here I show that when speeds are correctly calculated from the Glenrock trackway, the obtained values are clearly (about 50–80 percent) higher than the wrong values quoted by these authors. This support even more a significant speed capability for tyrannosaurs than claimed by Smith et al. (2016).

Table 2 of this paper.

	Speed (m/s)	Speed (km/h)
Smith et al. (2016)	1.24–2.33	4.5–8.0
This work	2.25–3.47	8.1–12.5

www.sciencedirect.com/science/article/pii/S0195667117301891?casa_token=RVY3AqQI__cAAAAA:2JP14GJSroEMn_eOLPiHBN1q_efz--0AFbQgPW0-k2hQ4D46AKsM1pEVXWeIBTd1fnlQpUpKFQ

[Supercommunist]

Just felt like reposting a link that Infinity posted that biomechanical studies seem to greatly underestimate the bone strength of animals, which may be why giant animals tend to have very conservative speed estimates.

svpow.com/2018/04/17/it-pays-to-stay-humble-before-nature/

[Supercommunist]

Has there been any research on how long tyrannosaurus and other giant theropods could "power walk"?

Would it be possible for a determined tyrannosaurus to outgas a healthy and active human over long distances.

[Infinity Blade]

I don't think anyone has ever determined how long a giant theropod could amble, although I know they determined that tyrannosaurids would have been most adapted to it.

Maybe a T. rex could do that (but I don't know for sure)? One thing that's worth mentioning is that when humans do persistence hunting, they're not running at full speed most of the time; doing so would be counterproductive to conserving energy over a long distance chase. Similarly, a T. rex wouldn't have to run at top speed either, just move at a brisk enough pace to keep track of a guy. Although, with its exceptional sense of smell, I think it can better afford to lose track of a human (or any of its real prey items) than a human could with their prey.

[Supercommunist]

Yeah, I guess it would be difficult to predict endurance since the respiratory system isn't preserved. BTW fun fact about humans, persistence hunting actually seems to be a pretty inefficient strategy for us.

Here is an account of an ultramarathon runner failing to catch a pronghorn after 5 years.

You could call Wolfe’s tactic of pushing an antelope until it collapses crazy, foolish, or futile. But technically, it’s called “persistence hunting,” and after five years of failed attempts, you could call Wolfe persistent.

By “doing well,” he means he finished second in the prestigious Western States 100-Mile Endurance Run. It’s the oldest 100-mile race, winding through the Sierra Nevada mountains and requiring competitors to climb a total of 18,000 feet. Anyone who finishes the race in under 24 hours earns a silver belt buckle. Wolfe finished it in 15 hours and 38 minutes. He also took second in the Ultra-Trail du Mont-Blanc and won $10,000 by placing first in the North Face’s 50 Mile Endurance Challenge.

This is a romantic idea: We human hunters have an innate ability to catch our prey through physical stamina alone. But Lieberman and other experts have recently published papers questioning his earlier theory. Critics say that conditions would have to be so exact for a human to successfully run down a deer or antelope that it seems unlikely persistence hunting was a key part of our evolution.

Scott Creel, a professor at Montana State ­University and a former ultrarunner for the U.S. national team, is one of the skeptics. While ­humans have run down critters like antelope, it’s unlikely that humans evolved specifically to run down prey. We, as a species, are just too slow.

www.outdoorlife.com/story/hunting/ultra-runner-persistence-hunting-pronghorn-wyoming-with-recurve-bow/