The Paleontology Size Guide: Calculate Dinosaur Size Yourself

[@TheVividen]

Check out Darius' GDI tool and Dino W's allometry calculators! GDI R Package: x.com/darius_nau/status/1654111177033625603 Darius' GDI Tutorial: kzbin.info/www/bejne/p3mcl61pndCggpI SV_POW GDI Tutorial: svpow.com/2011/01/20/tutorial-11-graphic-double-integration-or-weighing-dinosaurs-on-the-cheap/ Allometry calculator: docs.google.com/spreadsheets/d/104eb01OUY-To1S8-a15XMRRZFDnEmppOUe1DCRZVZao/edit?gid=0#gid=0 Convex-hull modeling underestimates mammals by 21%: pubmed.ncbi.nlm.nih.gov/22675141/#&gid=article-figures&pid=figure-1-uid-0 Another convex-hull modeling paper: peerj.com/articles/1432.pdf Campione & Evans 2020: onlinelibrary.wiley.com/doi/abs/10.1111/brv.12638

[@Nightscape_]

These videos would have really helped me when going through university. I'm retired now, but for those just becoming paleontologists, what a great resource!

[@TheVividen]

It's never too late to do what you love!

[@TheVividen]

I realized that Cretaceous Crusader joined the channel since I made the visual skeleton for this video, so I apologize for the lack of a shoutout at the end! This is all for you, CC!

[@cretaceouscrusader661]

Cheers. Thanks for the shoutout.

[@AndrewDavis-sj6mb]

@TheVividen how is your Friday, how do you view The Decepticons from Transformers and have you seen The Disney movie,WISH?

[@Aquarimax]

I love this ‘hybrid format’, the filming area looks awesome! Great video! 🎉🎉🎉

[@raptorjesus8054]

Raising the bar for paleo vids on youtube. Edge plagiarizes but Vividen does his homework

[@Agnes135]

The thing is as well, people don't realise how big a bull african elephant is. Sure seeing them in pictures is impressive. Seeing one up close in person is absolutely jaw dropping. They are absolutely enormous creatures

[@isaacthedestroyerofstuped7676]

I'm glad the Top Tier was left blank. People rarely think about just how many assumptions and data points are made in these models! It's the standard, so it makes sense to skip over this _if you're talking to colleagues._ When this data and research makes it to the public, these nuances are lobbed off and people just assume it to be accurate. Then they see the numbers change and hear a vague reason and think shit is just being made up! I enjoyed the mixed facecam/voiceover system! The voice change was a bit jarring, but I know for a fact the extra expressions and jestures help a lot of people in oaying attention and following a train of thought!

[@kellywilson5594]

Great video! Love the collaboration. (And that fabulous eyebrow near the middle...and the Tobuscus tribute at the end lol) I think the format works nicely

[@TheVividen]

KZbin had its peak with 2013 Tobuscus!

[@dinow269]

Magical Christmas Land is just taking a time machine to weigh the animals with a scale lol Also thank you for including my calculator, it means a lot that you think it’s noteworthy! I’ll definitely be checking out Darius Nau’s GDI tool.

[@DreadEnder]

I have to say this is definitely THE best palaeontology channel I’ve found.

[@TheVividen]

Thank you! That means a lot!

[@UnwantedGhost1-anz25]

Mighty kind of Madly Mesozoic to give this video a shout-out. I hope you both cook a collaborative video someday. And reach over a hundred thousand subscribers.

[@TheVividen]

Thank you! Madly's the goat. Have you seen our Spinosaurus collab?

[@UnwantedGhost1-anz25]

@@TheVividen Yes, I have. It was worth it. Great job working on it during the preproduction. No hard feelings from Madly to dunk on Spino with Tyrannosaurus Rex. 😅

[@DreadEnder]

I’ve been wondering about using ratios to estimate size or mass. Like how the jaw to gill ratio in fish is pretty consistent which was used to shrink the dunk. I know some studies have been conducted on it but I want to be as thorough as possible. There’s a surprising amount of relation within the physiology of organisms.

[@TheVividen]

There is a definite space for that, like with Engelmann's study that you mentioned. It's just tricky since the ratios can vary so much with phylogeny!

[@rosalinadeanda-zd6nn]

I agree, I can see the possibility of there being a ratio that is consistent within the physiology of an organism. But the problem is that individual variation is quite consistent, so the ratio could vary.

[@DreadEnder]

@@rosalinadeanda-zd6nn sure. Of course the more specimens the more accurate and precise the results but that goes for all the methods.

[@rosalinadeanda-zd6nn]

@@DreadEnder True. I just think that the possibility of variation could still remain consistent due to large populations. But, some animals have less individual variation than others.

[@AncientWildTV]

@@rosalinadeanda-zd6nn do you know some why animals have less individual variation than others?

[@Username-y2v]

my new teacher the elephant in the miniature looks like Muscle Man from Regular Show saying: Oh no brother

[@TheVividen]

He's only moderately terrified haha

[@Username-y2v]

​@@TheVividen He is analyzing all possible scenarios to get out alive, but he will play Gojo: nah i'd win They should call him Courage the cowardly elephant, like Courage the cowardly dog

[@TheVividen]

​@@Username-y2vJerry does in fact solo

[@Username-y2v]

@@TheVividen Henry equal 🗿

[@MatthiasG1899]

I have followed this video and arrived at T-Rex being 19 tons now

[@TheVividen]

Very real haha

[@BriEnr]

Your voice is nice and your content is good

[@BriEnr]

Your face is nice too

[@BriEnr]

I am very tired

[@BriEnr]

I think “magical christmas land” should bave “tume travel” in there lol

[@metalheadjakob]

Knowing you also play EDH makes me happy.

[@TheVividen]

Gishath all the way!

[@apex2000]

I'm curious the upper most list of a bipedal animal (before legs are crushed to dust) & how big legs would have to be

[@dariusrose9909]

Thanks again. Trying to do this with some of the Monster Hunter Monsters.

[@TheVividen]

That's a great idea!

[@monkeking8394]

6 Tonne Jaggi is gonna be crazy

[@PrehistoricMagazine]

Great video as always. Hope all is well with you. Mike

[@TheVividen]

Thanks, Mike! You too!

[@tiffanylamarca6914]

Great Video!!!

[@jodebever]

This will do wonders

[@TheVividen]

I hope so! I want this to be the ultimate DIY resource for paleontology enthusiasts so they won't run in to misinformation

[@jakfortin5957]

1.6 Tonne Spinosaurus is wild

[@TheVividen]

Allometry is bizarre haha. Its femur is so tiny that the formula assumes the rest of its body is tiny as well

[@jakfortin5957]

@@TheVividen I can't believe I got a reply from you lol. Made my day with that. 13 tonne Spinosaurus Aegyptiacus aka MSNM V4047 or NMC 41852, meet Cope and MUCPV-95 (Nizar release a new paper pls)

[@Imatroll_Icallcap]

Haha MSNM & NMC aren't spinosaurus specimens no more ​@@jakfortin5957

[@erikringdal844]

I am very impressed! One question: We Seem to be finding ever bigger dinosaurs, and the weight estimates for a certain length seems to being lowered, at the same time illustrations shows thinner legs, especially for sauropods, is that possible for a 50-80 ton specimen?

[@TheVividen]

I'm not sure I understand, but yes, sauropods could be absolutely huge! That goes for allometry and volumetry

[@petersmythe6462]

Convex hulls do not represent even a conservative lower bound on minimum mass because animals are not strictly convex. It is entirely possible and even likely for there to be hyperbolic or even strictly concave parts of an animal.

[@TheVividen]

Another reason why they shouldn't be considered as estimates by themselves!

[@shameimaru_aya]

*insert alxasaurus scream by mario lanzas* *AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA*

[@claudejones5171]

Kaiju theropods stand up

[@TheVividen]

Enabled by the power of math!

[@claudejones5171]

@@TheVividen damn. Guess I have more math for 300+ foot tall theropods 🥲

[@jurassicswine]

@@claudejones5171 you’ll need another planet if you want a theropod that big without it just folding in on itself

[@claudejones5171]

@@jurassicswine I got one cooking up, but I still need the layout

[@jurassicswine]

@@claudejones5171 heard the Empire had blueprints for a moon-sized object so maybe ask them once the whole Rebel situation is sorted

[@Coleptorasaurus]

Tiny detail but I have the same spinosaurus model in the bottom right corner lol

[@jurassicswine]

This is your Oppenheimer moment. Lord save us from the awesomebros. But this is an awesome video! Cool to see how the sausage gets made, even if _those_ kinds of paleo fans sorta ruined this topic for me.

[@TheVividen]

I'm glad you liked it! This took about two months of research and learning to make so I'm relieved that it seems to be getting a positive reception!

[@jurassicswine]

@@TheVividen it deserves a positive reception! At the end of the day science is all about sharing and comparing information, isn’t it? So even if I do have my reservations about the whole “mega”theropod size rat race, I really do see this as a net benefit overall. Being transparent about how paleontologists get these numbers is just as if not more important than the numbers themselves.

[@insectilluminatigetshrekt5574]

Most of this video applies to mammals, reptiles, and dinosaurs. What are the methods for fish, amphibians, and non-vertebrates?

[@superiorcybergodzilla5670]

I really need to know this

[@rosalinadeanda-zd6nn]

Amazing, amazing video. I personally love calculating the size of Prehistoric organisms. I found this video very useful and effective when calculating the size of Prehistoric organisms. Furthermore, I even tested one of the methods. I used Persons et al. and Larson's measurements on the femur circumference of FMNH PR 2081, also known as "Sue". I used the Limb Bone Circumference Allometry for bipedal animals, which gave me a body mass of around 8 tonnes. Furthermore, I will mention the fact that this method of estimating body mass in Prehistoric organisms can vary, so it can make estimates different from others. Additionally, "Sue's" femur has been suggested to have different measurements, but I decided to use the specific measurement I chose because it was quite broad. Amazing video, and all the Paleontologists and researchers that helped you are amazing too.

[@TheVividen]

Thank you for your kind words! I'm really glad you liked it!

[@DreadEnder]

I’m wondering to what extent these techniques have been used on extant animals to test reliability.

[@TheVividen]

Quite a bit, actually! I recommend reading Hurlburt 1999 and Campione & Evans 2020 for broad overviews of groundtruthing history.

[@DreadEnder]

@@TheVividen cool! Will do

[@petersmythe6462]

Finding an H. Sapiens humerus with only non-human apes as reference points would be... interesting with any of these methods. (Though in reality the fossil record is strongly biased the other direction. There are thousands of fossils humans including decently complete 3D skeletons, while the sum total of Panine ape fossil material is 3 teeth from an extinct subspecies (not species) of relatively modern Chimpanzee.

[@royjacksonjr.4447]

So, I guess Allometry works best for Allosaurus?😅

[@TheVividen]

Since there are so many femurs, it is pretty convenient!

[@ISURAH-484]

Great video

[@TheVividen]

Thank you!

[@MGM-Dude]

Cool video

[@TheVividen]

Thank you!

[@kaijuar2003]

GDI seems to be the best from what the video says, the ONLY problem is that I can't understand it well. I don't have a PC, just a mobile phone, so even if I did learn how to do it, I can't. Seems like I wasted some time, I'll have to put my speculative biology project in the back burner for now until I find a more simpler way to size up my animals.

[@Ornitholestes1]

Well, the nice thing about GDI is that you can theoretically do it using a ruler, pencil and a basic calculator. That’s how the method was used originally, back when it was first devised by Jerison in the 1970s. That is actually one of the important advantages it has over 3D modelling, it uses a mathematical representation of the shape that can easily be made simpler (less detail) or more complex (more detail), depending on the available computing power. It won’t be as convenient or as precise as the "pixel-precise" implementation shown in the video (which does the same stuff you would do manually, just a lot more quickly), but it is still a solid way to volumetrically calculate a body volume if you have a reconstruction that you can somehow measure. If you are looking to do serious scientific work, not having a PC is a big impediment no doubt (what do you type stuff on?). I’d really consider getting a cheap, pre-owned computer from somewhere. Those cost a fraction of what a typical smartphone costs (I’ve seen netbooks that were at least claimed to be functional for less than 30 € on ebay, and just barely functional is absolutely sufficient to run R on). Alternatively, there are publicly usable PCs in many places, e.g. libraries, that you might have access to, and which you could run a portable version of R (sourceforge.net/projects/rportable/) on from a flash drive. That being said, I’m fairly sure that even on a phone, there is probably some app out there somewhere that could be used to measure distances in pictures manually so that you can do a manual GDI. Or you could try to install R on your phone. It’s not an ideal solution because it sometimes won’t be able to install the packages you need, but it’s worth a try (I’ve managed to do it before, if you use Android, try installing R using the package management tools in termux), since sometimes it will work fine, at least for some applications. The gdi package is really small and just has two fairly basic dependencies, to the chances it will work on an R implementation on your phone are decent.

[@kaijuar2003]

​@@Ornitholestes1 Still isn't clear to me, I'll just stick to guesstimating or asking some to give an estimate based on the size comparison to a human.

[@DynamicFlux_2006]

0:37 since when did a cassowary became an expert?????

[@TroyTheCatFish]

Interesting 🤔

[@frankdughtank8327]

Whoop!

[@TheVividen]

Heck yeah!

[@d012k-n5t]

I would not imagine you to look like that

[@Carnosaur290]

Aquarimax pets sent me!

[@benyboy-fm7qt]

Sigmeah

[@TheVividen]

Skeletor

[@tyrannotherium7873]

I suck at math

[@TheVividen]

So do I! That's why much smarter people helped me write this video

[@tyrannotherium7873]

@@TheVividen really I thought you’re good at math

[@TheVividen]

​@@tyrannotherium7873Not at all haha. That's why it took so long to research this video--I wanted to learn how to do it all myself so I could actually explain the formulas from a perspective of having used them

[@TheVividen]

You did not include the toe bone of Uncle Leroy Jenkins' favorite Deinonychus specimen, "Crazy Tom." Due to you failing to recognize this pathologic specimen, which has been of considerable import to scientific advancement, I shall be unsubscribing and badmouthing you on every Discord server I am in. You should know that I have great clout in the amateur paleontology community and therefore I expect you to fear my judgment rawr

[@VitriolicThunder]

Nerd.

[@claudejones5171]

First