Animal Sizes

[Infinity Blade]

Does anyone know of any reliable body mass estimates for Basilosaurus?

[creature386]

We had a brief discussion on this in the profile thread, but I'm sure you've already read it:
theworldofanimals.proboards.com/post/43434/thread

[Infinity Blade]

I forgot about that. I wasn't able to access that paper before, but since I've started using Sci-Hub for papers I can't fully access, I can now.

I haven't read the paper in full, but you say that the allometric equation is not applicable to Basilosaurus. Other mass estimates for Basilosaurus in that table are closer to >5-6 tonnes.

[Infinity Blade]

Paraceratherium transouralicum

P. transouralicum appears to be the biggest species of Paraceratherium. The largest remains are represented by two giant cervicals (specimen AMNH 2618) and part of a central metacarpal (specimen AMNH 26175).[1] A volumetric estimate based on more complete remains that was then extrapolated to the size of these specimens resulted in a Paraceratherium ~480 cm at the shoulder and 16.4 tonnes.[1][2] Paul used a specific gravity of 0.95; Asier Larramendi considers a specific gravity of 0.99 to be more reliable, giving us a 17.1 tonne animal.[1]

Asier Larramendi states that, just like his estimate with the Sagauni II P. namadicus, this estimate needs to be taken with a grain of salt.[1] Most, if not all, Paraceratherium weighed much less than 17 tonnes. The composite skeleton produced by Paul (1997) weighed 8 tonnes[1] (7.8 tonnes, according to the original paper?[2]). Most large indricothere skeletons and bones indicate a similar mass, with the largest among these approaching only about 10 tonnes.[1]


References:

[1] Larramendi, A. (2015). Shoulder height, body mass, and shape of proboscideans. Acta Palaeontologica Polonica, 61(3), 537-574.
[2] Paul, G. S. (1997). Dinosaur models: the good, the bad, and using them to estimate the mass of dinosaurs. In DinoFest International Proceedings (pp. 129-154). Philadelphia: Academy of Natural Science Philadelphia.

[Ceratodromeus]

May 31, 2020 21:47:07 GMT 5 all said:

I would like to ask a question if I may which i'm aware in this thread one usually states the size not asks about it but I wish to ask a question i hope that's alright.

What is the size of Crocodylus robustus. Wikipedia states that it is about the same as Nile crocodile. But its been my experience that wikipedia is very conservative in their  statements simply because if they made statement that is not 100% conservative that could be used against them. For example they state that maximum size of Titanoboa is 10-12 meters,  but 12 meters is the average size of titanoboa while largest ones are about 14 meters. The larges colossal squid was supposed to be 8 meters according to them as new information came in they changed it to 9-10 meters. However according to documentaries the largest colossal squid is up to 16 meters. So what is the right answer. 

In a book I read. And yes it was a cryptozoolgy book which most of you consider pseudoscience. And yes I probably already  know what the answer will be. However according to this book skull of the C.robustus  was about 80 cm. From other article, Pdf this time not a criptozoology book. It was stated that C.robustus had relatively short snout in comparison to its body length. Would that not suggest that it was closer in size to salt water crock than to Nile crock?

I know I will be ridiculed for suggesting that but I rather keep the open mind and all though I don't know if its true I'am willing to entertain the notion. 

What is the size of Crocodylus robustus. Wikipedia states that it is about the same as Nile crocodile. But its been my experience that wikipedia is very conservative in their statements simply because if they made statement that is not 100% conservative that could be used against them.

I will look more into this issue, but "wikipedia" is not the only source stating Voay robustus to be around the size of a nile crocodile; Bicklemann and Klein (2009)^{1} also states this in the beginning of their article. Also, wikipedia is hardly conservative, especially when it comes to reptiles and crocodilians in particular. They tend to lean way more on the liberal, higher lengths and body masses. 

Also, an fyi, it is no longer referred to as "Crocodylus robustus", it has been placed in its own genus, the aforementioned Voay, where it is the only species currently recognized.

For example they state that maximum size of Titanoboa is 10-12 meters, but 12 meters is the average size of titanoboa while largest ones are about 14 meters.

Where do you get this from? average figure is based on what?

From Head et. al(2009)^{2}


"Both vertebrae were estimated to be located 60-65% back
along the precloacal vertebral column from the axis-atlas complex.
Regressions of vertebral width from this region against body lengths
for extant boines indicate a snout-vent length (SVL) of 12.01 ± 2.04 m
(39 ft) and a total body length (TBL) of 12.82 ± 2.18 m (42 ft) for
Titanoboa. Incorporating SVL values ofthis study into the relationship
between length and body mass determined for extant Eunectes murinus
(green anaconda)2and Python natalensis (southern African python)15
results in an estimated mass for Titanoboa of 1,135 kg (1.27 ton) with a
range of 652-l,819kg (0.73-2.03 ton)"

The larges colossal squid was supposed to be 8 meters according to them as new information came in they changed it to 9-10 meters

It has never been uncommon in living species for size revisions to occur when larger animals are figured to, or have been seen to, attain larger sizes. That being said, a variance of ~3ft(or 6 on the high end) is not substantial. Not in a deep water invertebrate especially.

However according to documentaries the largest colossal squid is up to 16 meters. So what is the right answer.

The one with in vivo measurements. Not hearsay from a documentary.

In a book I read. And yes it was a cryptozoolgy book which most people consider pseudoscience.

Fixed it

It was stated that C.robustus had relatively short snout in comparison to its body length.

Which reference is this from?

Would that not suggest that it was closer in size to salt water crock than to Nile crock?

The nile croc and saltwater croc are virtually identical in size. That being said, saying something is "nile croc sized" is inherently misleading when you consider that they vary so much in body size depending on their age. They attain sexual maturity at sometimes 2.5m in length, and get as large as 6. So yeah.  I'll need to read more about this thing before i can give you a definitive answer on body size estimation.

Reference
{1}Bickelmann, C., & Klein, N. (2009). The late Pleistocene horned crocodileVoay robustus(Grandidier & Vaillant, 1872) from Madagascar in the Museum für
{2}Head, Jason J., et al. "Giant boid snake from the Palaeocene neotropics reveals hotter past equatorial temperatures." Nature 457.7230 (2009): 715-717.

[Infinity Blade]

This post isn't meant to prove a size estimate, but recently I took a look at a paper regarding the rates of dinosaur body mass evolution using limb bone circumference (this paper->). It's nothing new, but there were two body mass estimates that particularly stuck out to me: those for Triceratops horridus and Iguanodon bernissartensis (estimated at 14,000 kg and 15,000 kg, respectively). Now, as Campione will later tell me, it's really the body size estimate range that's important (at these body sizes, the error margins are large), but yesterday I decided to ask him about the really high point estimates, particularly on whether they're based on exceptionally large specimens or fail to take into account differing proportions in different species (the latter was what I suspected). Basically, I wanted his input on whether or not we could really trust these estimates. He responded. This was the conversation below.





What do we all think of this?

theropod

[Supercommunist]

Anybody know how big the average grizzly bear is? IIRC voidmeister posted a study that they weighed around 500 pounds.

[Supercommunist]

Not much info on black caiman sizes but one paper indicates they are relatively light compared to other crocodilians:

The reptile was identified asa black caiman measuring 13 ft (4 m 21 cm) and, weigh-ing around 350 kg.

www.researchgate.net/publication/50288317_A_Fatal_Attack_on_a_Child_by_a_Black_Caiman_Melanosuchus_niger

If IIRC a crocodile of that length would usually be several hundred pounds heavier.

[theropod]

Aug 13, 2020 20:07:43 GMT 5 Infinity Blade said:

This post isn't meant to prove a size estimate, but recently I took a look at a paper regarding the rates of dinosaur body mass evolution using limb bone circumference (this paper->). It's nothing new, but there were two body mass estimates that particularly stuck out to me: those for Triceratops horridus and Iguanodon bernissartensis (estimated at 14,000 kg and 15,000 kg, respectively). Now, as Campione will later tell me, it's really the body size estimate range that's important (at these body sizes, the error margins are large), but yesterday I decided to ask him about the really high point estimates, particularly on whether they're based on exceptionally large specimens or fail to take into account differing proportions in different species (the latter was what I suspected). Basically, I wanted his input on whether or not we could really trust these estimates. He responded. This was the conversation below.





What do we all think of this?

theropod

Well, you probably guessed my position on this, I tend to think that a volumetric mass estimate informed by all that is known about a species’ morphology will tend to produce a result that is more dependable for that species. A priori we don’t necessarily know whether one species had proportionately greater limb robusticity or not. Which is not to say Campione et al.’s regressions aren’t very useful, of course, in fact they are exactly what is needed for a study like the one you mention where it is about overall trends and not about necessarily getting THE most accurate estimate for one individual species or specimen.

EDIT: The circumferences he lists in the supplement are 498.5+491.5 mm for the Triceratops horridus, specimen AMNH 5033. Using those with Campione et al.’s MASSTIMATE package gives me the following (note error bars):
> library("MASSTIMATE")
> QE(HC=491.5, FC=498.5, equation="phylocor")
      log.QE       QE lower.QE upper.QE
[1,] 7.152979 14222611 10662691 17782530

[Infinity Blade]

I tried looking through the supplementary material, but I had overlooked the Triceratops data (probably because at the time I was more focused on the estimate range for Shantungosaurus). So, if I'm interpreting this correctly, the actual range is anywhere between 10,662-17,782 kg?

In retrospect, I feel like I should have made this comment before Campione's most recent study on regressions vs volumetric estimates (which, perhaps surprisingly, found that they're mostly consistent with each other) came out (Campione & Evans, 2020->).

[theropod]

The formula given in the supplement of Benson et al. 2014 is apparently the "raw" (not phylogenetically corrected) regression:
mass (kg)=[1] mass = 10^a/1000
a = 2.749*log10(FC + HC) – 1.104

> 2.749*log10(498.5+491.5)-1.104
[1] 7.131001
> 2.749*log10(498.5+491.5)-1.104->a
> 10^a/1000
[1] 13520.76
> library(MASSTIMATE)
> QE(HC=491.5, FC=498.5, equation="raw")
      log.QE       QE lower.QE upper.QE
[1,] 7.131001 13520761 10055390 16986132


But as Benson et al. wrote, their 14 tons were only given to two significant figures, so that in itself is really consistent with both the raw and the phylogenetically corrected regression.

So yeah, basically something between 10 and 17 or 18 tons for that specimen based on the limbbone circumferences.

[Ceratodromeus]

Sept 16, 2020 1:59:51 GMT 5 Supercommunist said:

Not much info on black caiman sizes but one paper indicates they are relatively light compared to other crocodilians:

The reptile was identified asa black caiman measuring 13 ft (4 m 21 cm) and, weigh-ing around 350 kg.

www.researchgate.net/publication/50288317_A_Fatal_Attack_on_a_Child_by_a_Black_Caiman_Melanosuchus_niger

If IIRC a crocodile of that length would usually be several hundred pounds heavier.

Well, in the first photo, the individual looks a little skinny to me.


But it is comparable to alligators of comparable length; here is some info from large bull alligators in florida with similar TBL


You can see the variance in body mass for alligators of similar lengths there as well, i'd suspect body condition and of course environment is a pretty significant aspect in that. The Orange lake alligator was an absolute unit, much bigger than the other bulls in that sample. It is also very muched aligned with the weights of male nile crocodiles from Lake rudolph(Taken from Graham's thorough thesis on these animals)


So, i wouldn't say they are light in comparison, but that distanced dorsal view of the black caiman in question does make it look a little bit off. The lateral shot doesn't, so maybe it isn't a skinny animal. I hope that helps

[Ceratodromeus]

A 12ft 1in(3.68m) alligator from the Mississippi river, found to have grown at a significant rate since it was first tagged in 2011; fueled by introduced asian carp heavy diet 

[Infinity Blade]

I explored the topic of the largest blue whales known. The most liberal estimate I could find was an animal that "must have scaled at least 200 tonnes" from the Guinness book of animal facts and feats (1982)-> (both screenshots herein have been taken from this book via the Internet Archives). This specimen, killed in Walvis Bay, SW Africa on July 13, 1924, was a female that was 27.7 meters long described as "very fat". This fat reportedly weighed 51.85 tonnes, and on this basis is claimed to have weighed at least 200 tonnes. However, this specimen was not weighed piecemeal.



The largest specimen that was weighed piecemeal was killed in 1947 and weighed 190 tonnes. This specimen was 27.6 meters long and killed alongside another female that weighed 140 tonnes and measured at 28.7 meters long. Specimens corresponding to these exact lengths and body mass were reported in Lockyer (1976)->.



Although they're not huge departures from each other (though again, the former estimate is at least 200 tonnes), I think we can dismiss the estimate for the 1924 specimen as highly suspect because 1) it was not weighed piecemeal, 2) the only basis for its 200+ tonne weight is oil yield, 3) it was killed more than two decades before the 190 tonne female, and thus might have been more likely to have been exaggerated by decades-old whalers, and 4) the original source, Risting (1928), never attempts to estimate the total mass of the whale (he never even estimates the mass of all the oil combined, he just mentions that it indeed yielded 305 barrels of oil). It's worth noting that up to 35% of a blue whale's body mass can be fat.

"For wild animals in today's world, body fat content is directly correlated with body size, from less than 5% in mice to about 35% in blue whales." (Bray & Bouchard, 2014).

Therefore, if this supposed 200+ tonne specimen was "very fat", the aforementioned fact would need to be considered (i.e. the greater the body fat percentage this whale had, the more toned down the total body mass figure would be).


Of course, this is just for the largest blue whale specimens. According to Nishiwaki (1950)->, physically mature blue whales average approximately ~90-110 tonnes.

[Infinity Blade]

Oct 23, 2019 0:05:47 GMT 5 Infinity Blade said:

Palaeoloxodon namadicus

In 2015, paleontologist Asier Larramendi published a paper-> where he documents his own size estimates for various extinct proboscidean taxa. P. namadicus is commonly known as that elephant that weighed 22 tonnes. This size was attributed to one particular specimen (Sagauni II), represented only by a distal femur portion. This portion has been reported to be nearly one-quarter larger than that of a supposedly not yet fully grown P. namadicus individual that has been estimated to weigh 13 tonnes (Sagauni I). Assuming this portion was 20% larger, the elephant's whole femur would have been 1,900 mm in length, giving us an elephant 5.2 meters tall at the withers and 22 tonnes in body mass.[1]

The only source of measurement for the femur fragment's size is Prinsep (1834). The fact that this specimen has presumably not been seen, let alone measured, in more than 180 years is sufficient grounds for us to view the size estimate with heavy skepticism. Asier Larramendi himself notes that the specimen must be restudied. The specimen is said to "likely" be stored in the Indian Museum of Kolkata, implying that it is not certain that they are there. Until this specimen is recovered, the size estimate will not be anything more than speculative.[1]

Sagauni I is stated by Asier Larramendi to likely be a young individual that could have grown considerably larger, on the grounds that the femoral head was detached.[1] However, looking at the original source describing this material, it appears that there is another very large specimen that was found with detached femoral condyles.[2] Presumably, this is Sagauni II, given that this specimen is a single distal portion of a femur, which would have condyles. It seems very suspect to conclude that Sagauni II would have had more room to grow solely on the basis that its femoral condyles were detached, especially if it were supposedly already 22 tonnes. Even Asier Larramendi himself notes that complete long bone epiphysis fusion can occur as late as age 50 in modern elephants (regardless of sex), a point at which they have long since achieved or surpassed the expected adult body mass for their species. Therefore, it is not a given that Sagauni I was necessarily a young individual simply due to its detached femoral head, if what are certainly fully grown individuals also have incompletely fused long bone epiphyses. Likewise, an alternative explanation for the broken off portions of the femora may simply be taphonomy; Sagauni I has femora that are clearly broken, fragmented, and incomplete, while Sagauni II is one single isolated femur fragment.[1][2]

In conclusion, in Asier Larramendi's own words in Appendix I of his own paper, "The estimated body size for...Palaeoloxodon namadicus (Sagauni II), should be taken with a grain of salt."[1]

References:

[1] Larramendi, A. 2016. Shoulder height, body mass, and shape of proboscideans. Acta Palaeontologica Polonica 61 (3): 537–574.
[2] Prinsep, L. 1834. Note on the fossil bones on the Nerbudda valley discovered by Dr. G.G. Spilsbury near Narsinhpur. Journal of the Asiatic Society of Bengal 3: 396–403.

Just thought this might be worth sharing, and I couldn't think of a better place to put it. It has come to my attention that another paleontologist (Roberto Díaz Sibaja) has also expressed skepticism on the 22 tonne estimate for P. namadicus. The paleontologist said this on Facebook.

"This is based on a distal portion of a femur... That the author didn't even check as he says: " Of course, it would be of special interest to revise the Indian Museum of Calcutta collection where these fossils might be stored, in order to study and confirm in particular the colossal size of the distal femur part." This is NOT how we do real science.

Also the only referred giant femur is from Prinsep (1834), with 63 inches (in this image). But the femur is not complete, and maybe more important: in 1834 an inch was not an unvariable measure unit and it was slightly different across the world. And that's why we measure the old specimens to check their measurements. That's why Amphicoelias fragillimus is also a very doubtful animal. Again, taking a measurement from 181 years ago as absolute truth is a huge mistake, and is not how science should be done.

Also, taking one small fragment of bone and scaling to a complete set of measurements (shoulder height) is not a good method. Mainly due to allometric relationships between organic parts. Just take a look at different species of mammoths, they do not share the same proportions. So Why this elephant is special?

In synthesis, this titanic elephant is the Amphicoelias fragillimus of the mammals. More likely, a myth. But a useful myth, thus we can see to gigantic sized mammals, and question their size.

Just don't buy the conclusions so fast."

www.deviantart.com/harry-the-fox/art/Palaeoloxodon-namadicus-Size-733960472

He points out some of the same things I pointed out, but also noted something (the thing about inches being variable across the world at the time) I never knew until now.