Animal Sizes

[Supercommunist]

^Thanks.

Small sample of tegu weights.

repository.si.edu/bitstream/handle/10088/11118/932280b2-799b-4694-a311-0a43de1308cc.pdf?sequence=1&isAllowed=y\

bioone.org/journals/Journal-of-Zoo-and-Wildlife-Medicine/volume-49/issue-2/2017-0089.1/INTRAMUSCULAR-ADMINISTRATION-OF-KETAMINE-MEDETOMIDINE-ASSURES-STABLE-ANAESTHESIA-NEEDED-FOR/10.1638/2017-0089.1.short

[Infinity Blade]

Recently, a study came out that found a trend of decreasing body size through time in the European cave lion (Panthera spelaea). One specimen of P. s. fossilis was estimated at over 500 kg.

In truth, there were three different methods used to estimate body size in these lions. For the Sambir lion (the specimen in question), an estimate based on calcaneus length resulted in an estimate of 912 kg. This is obviously unprecedented in size for any felid, and the authors consider this to be relatively unreliable. However, they also feel that an estimate based on the length of the first molar is an underestimate (353.2 kg). A third method, multiplying m1 length by breadth, resulted in 440 kg.

The authors do not specify how >500 kg was arrived at. In fact, in context, it appears to be an arbitrary, if educated, inference. Take it for what you will.

References:

Marciszak, A., Ivanoff, D.V., Semenov, Y.A. et al. The Quaternary lions of Ukraine and a trend of decreasing size in Panthera spelaea. J Mammal Evol (2022). doi.org/10.1007/s10914-022-09635-3

[Supercommunist]

Gaurus an inactive poster from CF had a great thread about large herbivore dimensions.

carnivora.net/viewtopic.php?p=19076#p19076

Cape buffalo.

Grubb (1971) recorded weights for cape buffalo: 8 bulls from Serengeti had a mean weight of 751 kg (1,656 lbs), 6 bulls from Kenya had a mean of 768 kg (1,693 lbs) and the mean of 2 cows from Serengeti was 447 kg (985 lbs). Stanojevic (2015) weighed 37 cape buffalo cows and recorded a mean weight of 464 kg (1,023 lbs).

Gandy and Reilly (2004) provided horn measurements for 29 (trophy) cape buffalo bulls: the mean horn spread from tip-to-tip in 14 broomed buffaloes was 165 cm (65 inches) and mean horn length was 77.1 to 79.2 cm (30.35 to 31.2 inches). Likewise in 15 non-broomed buffaloes the mean horn spread was 191.8 cm (75.5 inches) and mean horn length was 89.5 to 89.7 cm (35.23 to 35.32 inches).

Gaur

Guatemala (2015) recorded body weights for Indian gaurs: the average weights were 831 kg (1,832 lbs) in a sample of 18 bulls and 570 kg (1,257 lbs) in a sample of 2 cows. Ahrestani (2018) provided weights for Indian gaurs shot by hunters: the mean body weight of 6 bulls was 829 kg (1,827 lbs) and of 2 cows was 572 kg (1,261 lbs).

American Bison.

Feldhamer, Thompson and Chapman (2003) reported body weights for both subspecies: the greatest mean weights for plains bison were 769 kg (1,695 lbs) and 454 kg (1,001 lbs) for bulls and cows respectively. The greatest mean weights for wood bison were 910 kg (2,006 lbs) for bulls and 540 kg (1,191 lbs) for cows.

Meagher (1986) provided figures for skull lengths in bulls: skulls measured 50 to 58.3 cm (19.7 to 23 inches) in plains bison and 56.2 to 60.4 cm (22.1 to 23.8 inches) in wood bison.

Halloran (1960) recorded horn measurements for plains bison: the mean horn span from tip-to-tip in a sample of 21 bulls was 61.5 cm (24.2 inches), and in a sample of 16 cows the mean was 38.8 cm (15.3 inches).

Hippo:

Owen Smith (1988) recorded weights for hippos in a large sample culled in Uganda: bulls attained an average body weight of 1,480 kg (3,263 lbs) and cows attained an average weight of 1,365 kg (3,009 lbs). The heaviest bull and cow recorded in a sample culled in the Luangwa River were 1,600 kg (3,527 lbs) and 1,565 kg (3,450 lbs) respectively.

Eltringham (2010) reported body weights for hippos culled in Uganda: bulls had an average body weight of 1,536 kg (3,386 lbs) and the heaviest bull weighed 2,065 kg (4,553 lbs). The average body weight for cows was 1,386 kg (3,056 lbs) and the heaviest cow weighed 1,716 kg (3,783 lbs). He also reported weights from East Africa: bulls had a mean live weight of 1,490 kg (3,285 lbs) and the heaviest bull weighed 1,714 kg (3,779 lbs). The cows' mean weight was 1,277 kg (2,815 lbs) and the heaviest cow weighed 1,401 kg (3,088 lbs). Likewise in the Kruger National Park: bulls had a mean body weight of 1,490 kg (3,285 lbs) and the heaviest weighed 1,999 kg (4,407 lbs). The cows' mean body mass was 1,321 kg (2,912 lbs) and the heaviest weighed 1,674 kg (3,691 lbs).

Chomba (2016) recorded shoulder heights for hippos: bulls and cows of older age groups measured about 140 to 150 cm (55 to 59 inches) tall.

Chritz, Blumenthal, Cerling and Klingel (2016) measured three lower canine teeth for hippo bulls: the mean tusk length was 46.3 cm (18.2 inches).

carnivora.net/viewtopic.php?p=19076#p19076

[Supercommunist]

Dakotaraptor leg length.



Anybody got reliable weight estimates for the large dromaeosaurids? Most of the weight estimates I see seem to conserative.

[Supercommunist]

Polar bear

"In Hudson Bay, the mean scale weight of 94 males >5 years of age was 489 kg. The largest bear in that group was a 13-year-old, which weighed 654 kg (Kolenosky et al. 1992). The heaviest bear we have weighed in Alaska was 610 kg, and several animals were heavy enough that we could not raise them with our helicopter or weighing tripod. Some animals too heavy to lift have been estimated to weigh 800 kg (DeMaster and Stirling 1981). Females are smaller, with peak weights usually not exceeding 400 kg. Total lengths of males in the Beaufort Sea of Alaska ranged up to 285 cm. Such an animal may reach nearly 4 m when standing on its hind legs and is 1.7 m shoulder height when standing on all four legs. Chest girth for large males is close to 200 cm. Although smaller, females in the Beaufort sea were as long as 247 cm with chest girths up to 175 cm."

Source: The Polar Bear — Ursus maritimusBiology, Management, and Conservation by Steven C. Amstrup, Ph.D.

[Infinity Blade]

Recently, a giant pangolin (Smutsia gigantea) in Gabon was weighed, and then had tissue samples taken and radio-collared. This pangolin was a male and weighed 42 kg, the largest on record (link->).

PhD student Ruth Smith with a 42kg male giant pangolin (Smutsia gigantea), the largest on record, found in Gabon by Dr David Lehmann and the Agence Nationale des Parcs Nationaux. The pangolin had just had tissue samples taken and a GPS fitted in order to learn more about this incredibly elusive and rare species.

PhD student Ruth Smith with a 42kg male giant pangolin (Smutsia gigantea), the largest on record, found in Gabon by Dr David Lehmann and the Agence Nationale des Parcs Nationaux. The pangolin had just had tissue samples taken and a GPS fitted in order to learn more about this incredibly elusive and rare species.

Such weights in pangolins aren't unprecedented. Adult male Indian pangolins (Manis crassicaudata) measure between 137 and 177 cm from the snout to the tip of the tail, and weigh between 20.4 and 48.8 kg. The largest individual recorded so far was 48.76 kg and 176.8 cm in total body length.

The Indian pangolin (Manis crassicaudata) is one of the eight extant pangolin species in the world, listed as “endangered” by the International Union for Conservation of Nature (IUCN). The species is native to the Indian subcontinent. The Indian pangolin population in Sri Lanka is geographically isolated from the mainland population and therefore, could possess morphological adaptations to the unique environmental conditions in the island. However, an accurate description of the morphological features has not been attempted for Indian pangolins occurring on the island. This study described the morphological features of Indian pangolins based on observations made on 27 specimens from Sri Lanka. The adult male Indian pangolin measures between 137 and 177 cm from the snout to the tip of the tail and weighs between 20.4 and 48.8 kg. The largest Indian pangolin recorded so far from any of its range counties, weighing 48.76 kg and measuring 176.8 cm in total body length was recorded in this study. Indian pangolins recorded from Sri Lanka on average bear 511 ± 21 scales. Three major scale morph/types are further described.

The Indian pangolin is sexually dimorphic, and males are much larger than females of the same age. The largest female individual sampled in this study was 7.33 kg. However, this does not reflect the true maximum weight for adult females, as this individual was a subadult.

The largest female specimen weighed 7.33 kg, however, this does not represent the true upper limit of body weight in females as it was observed for a subadult.

www.mdpi.com/2076-2615/11/1/25

[Supercommunist]

Wonder how much of that weight is just scales? I tried finding out how heavy a tortoise/turtles shell is compared to the rest of its body but I couldn't find anything reliable.

[Infinity Blade]

Dec 10, 2022 5:20:36 GMT 5 Supercommunist said:

Wonder how much of that weight is just scales? I tried finding out how heavy a tortoise/turtles shell is compared to the rest of its body but I couldn't find anything reliable.

Idk. For some reason I’d imagine the total number of scales weighs less relative to the pangolin than a tortoise shell is relative to the rest of the tortoise, but idk. It could be I’m underestimating how heavy all that armor is (mail didn’t seem that heavy to me either, until I held a small sample of it).

As for your Dakotaraptor question, I’d honestly hold off on anything related to it for the moment. At least until/unless the remains could be recovered and studied again (the author who described it restricts access to it and is under (rightful) hot water right now with regards to a different paper).

[Supercommunist]

Yacacre caimans:



www.researchgate.net/publication/285696550_Nesting_of_Paraguayan_caiman_Caiman_yacare_in_Brazil

[Supercommunist]

Leopard:



Cougars:



Mexican Jaguar and cougars:



Elk:

[Supercommunist]

Clouded leopard and striped hyena.

[Supercommunist]

Samson the largest shire horse:

[theropod]

T. rex (average size)

Certain…issues (see Carr et al. 2022) with that study notwithstanding, the recent paper by Paul and colleagues (where they purport the existence of three separate species of Tyrannosaurus, all of which, as most theropod researchers seem to agree, aren’t reliably distinguishable from T. rex and are therefore junior synonyms of that species) provides a nice compilation of measurements of various T. rex specimens. Here I’ve tried estimating the average size for T. rex (adult only) based on this dataset.

[m&m] I compiled the skeletal measurements from Paul et al. 2022, and excluded exclusively dental measurements, thereby dropping two of the 36 specimens from the analysis. In the remaining 34, 26 have reported femoral measurements, while 8 only have other skeletal dimensions. I analyzed both the femur-only dataset and a combined dataset where I estimated the femur length and circumference based on maxillary, dentary, humerus or metatarsal 4 length (depending on which were available, where multiple were known, I took the mean for each resulting estimate.). I also excluded the specimens USNM 6183 and LACM 23845 (which were in the dataset, but likely represent immature individuals), resulting in an overall number of 32 specimens, probably representing a large share of all decently preserved T. rex specimens that are known. For further details of the statistical analysis, see my knitted R code here→. You can also download the dataset and the code I used to analyze it here→.

Results and Discussion:
This is what the resulting femur length and circumference distribution looks like:


The mean femur length is 122 cm (90% CI 120-125 cm, preserved femora only, n=24) to 123 cm (90% CI 121-125 cm, full sample, n=32). That these two figures are so close to each other suggests to me that they are fairly trustworthy, and that including or excluding non-femur specimens in the sample does not have a major impact on the resulting mean size. Mean femur circumference based on only the 24 femora is 52.6 mm. When including estimated values for the 8 non-femur specimens, the value stays very similar (52.4 cm). However is should be noted that (unlike for femur length) the linear models for predicting femur circumference from other measurements tend to lack significance, so this should only be taken as indicative.

So mean femur length for T. rex ends up at about 123 ± 2 cm, and mean femur circumference is about 53 ± 1 cm.

We can estimate body size from that by comparison with FMNH PR 2081/Sue (being the most complete specimen). Based on this (and Hartman’s 2013 skeletal, length and mass estimate, ad 12.3 m and 8.4 tons), the average(-length) T. rex would have been about 11.5 m long and massed 6.3-6.8 t (depending on whether we scale mass from the femur circumference, which might be a bit too conservative since sue is a robust specimen, or the femur length).


References:
Carr, T.D., Napoli, J.G., Brusatte, S.L., Holtz, T.R., Hone, D.W., Williamson, T.E. and Zanno, L.E. 2022. Insufficient Evidence for Multiple Species of Tyrannosaurus in the Latest Cretaceous of North America: A Comment on “The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus”. Evolutionary Biology 49 (3): 327–341.
Hartman 2013 (online): North vs South Redux: Mass Estimates. www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013 retrieved April 14th, 2023.
Paul, G.S., Persons, W.S. and Van Raalte, J. 2022. The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus. Evolutionary Biology 49 (2): 156–179.

[spartan]

How large did Arctodus simus get?

[Infinity Blade]

Apr 24, 2023 22:54:40 GMT 5 spartan said:

How large did Arctodus simus get?

This isn't a rock solid answer, but I think maximum body mass estimates of ~1,200 kg are about right. Even the Arctotherium angustidens paper puts A. simus at that size at max.

“Tremarctines display a wide range in body size, from gigantic (e.g., Arctotherium angustidens and Arctodus simus, up to 1,200 kg)” (Soibelzon et al., 2011).

An average body mass of ~700-800 kg still seems to be accepted in recent works.

"Finally, the short‐faced bear (A. simus) is one of the rarest fossil taxa at RLB (Figueirido et al., 2017), as well as the largest. With an estimated body mass of 700−800 kg (Christiansen, 1999), this taxon exceeds the average body masses of extant ursids, with only the polar bear (~650 kg average body mass; Wilson, Mittermeier, Cavallini, 2009) of comparable stature. Only four preserved ossicular specimens have thus far been recovered from A. simus." (Dickinson et al., 2022).