Without a significant sample size and very distinctive differences to use as exemplar, it is basically impossible to tell if these variations are individual-to-individual or species-to-species ones. I mean, there is still a debate over whether certain smaller "T.Rex's" are smaller species, younger representations, or even separate species that are not T.Rex.
Didnt you hear? They found half a sliver of a fossilized toenail recently. Of course we get all new Tyrannosaurs. You didnt think they would call it a boring Sauropod, did you?
Nanotyrannus was a proposed genus of small Tyrannosurids, however, it was later realised that it was a juvenile T. Rex. Tyrannosaurs had such a monopoly as apex predator that the niche of medium sized carnivore was filled by younger Tyrannosaurs.
Well, the line between species is somewhat arbitrary to begin with. The only reason its so easy to draw that line with (most) modern day animals is because all the transitional forms that connected them have died out. Just look at the age old debate on where our own ancestors "stopped being 'just apes' and started being human".
@@juanjoyaborja.3054 I know there's no evidence of mid sized carnivores sharing T.Rex environment and time period but that doesn't mean they didn't exist...
Can fossil specimens be designated as subspecies, or is that only possible for living organisms? It seems certainly possible that there could be distinct morphs of Tyrannosaurus, but not enough to actually warrant splitting the species.
I don't think so, the best you can do is suggest a chronospecies/ancestral species as is implied with Tyrannosaurus imperator in this paper. If you can get some genetic information sure. But subspecies, and even different species of the same genus may not be distinct anatomically. A lot of these Tyrannosaurus rex specimens could have looked different on the outside, but unfortunately there's no way we will ever know. At least, not in any formations where Tyrannosaurus occur.
Fossil subspecies can be named if you have a HUGE sample size of individuals (10,000s) and the very slight differences are consistent and unambiguous. Happens with many marine invertebrate taxa (brachiopods, bryozoans, conodonts, foraminifera etc.)
In living animals, sometimes even different species are only really able to be identified through soft tissue and/or DNA. I can't think of it now, but I feel I've heard of modern animals often used to tests undergrads studying bone structures due to the two species having almost identical skeltons (and if memory serves, it is two related animals but not ones you would mistake for the same species of you saw them in the flesh - think, like, Leopards and Tigers. Those are not the species I'm thinking off, but imagine for a minute that, given only their skeletons it took an amazing attention to detail and a full knowledge the same handful of differences to be able to correctly identify which was which, when given the two living animals any first grader is able to spot the difference.) Knowing this to be the case in certain living species, it's not difficult to imagine that an animal that lived over such a large chronological range may have had many different subspecies and even species. But it could be the majority of changes were to the soft tissue, behavior, or other factors that we are unlikely to be able and catalog based on fossils alone..
That has been suggested for some of our near relatives, particularly Neanderthals, so the idea that it CANNOT be done for fossil animals is false. In fact, I'm pretty sure the suggestion was made before DNA was recovered and analysed. Honestly, whether we're talking about species or planets, nature tends not to divide things nicely into well-defined categories for us. That's not to say there are no boundaries, but the optimal place to put them is hard to define. The mass of Pluto can be scientifically measured, as can its orbit; whether we choose to call it a planet is more about us than about Pluto. It's much the same with some of the species/subspecies questions.
@@Scoobywoo7447 no bro..!! I'm taking about animals like cow, rhino, deer, giraffe etc. Even triceratops could also be in this list. I think you got it, you are smart enough!
So far it seems pretty spurious to me. Another palaeontologist not on the team said he thought the team had set out to see if the known T. rex fossils could be split into separate species, and lo and behold, they did. They saw what they wanted to see, in his words.
One thing must be mentioned about this paper. Gregory S. Paul is involved. Now for people who don't know, Paul is a famous dinosaur artist who likes to think he is a Paleontologist. He is a really talented artist, but he has no doctorate. Now Paul is also famous for another thing. The man loves to try to destroy established genus names. The whole thing about Deinochyus being an invalid taxon to Velociraptor? That was his doing in his "Predatory Dinosaurs of the World" book. He has also tried to eliminate many other names including Coelophysis, and most notionally for here, Tarbosaurus. He has for decades now considered Tarbosaurus just a species for Tyrannosaurus, something that was not peer reviewed, and has kept putting this little detail in the various books he has written. So here's the big thing here, this new paper he is attached to, is also an attempt to strengthen and legitimize what he did to Tarbosaurus. I can see why Philip Currie retracted his name from it.
Unfortunately this happens a lot in science, especially in areas that have politicized. It's very hard, and maybe even impossible to find an unbiased study in regards to the future climate, and has been like that ever since climate change has been politicized by the like of Al Gore who have made millions off of it. (I'm not saying climate change doesn't exist, just that the issue is now far more political and biased then it is actual science).
Except it's not a newly discovered dinosaur, all the T-Rex experts and paleontologists disagreed with this paper, there just isn't enough evidence and the differences aren't enough to be whole new species
It'd be cool if there were more than one Tyrannosaurus species, but from the sound of it, the paper in question doesn't present that great of an argument. Kind seems like there's more evidence for multiple species of Spinosaurus. Now I wouldn't be surprised if more than one Tyrannosaurus species did actually exist, but I don't think we're at a point where just looking at the bones could prove it.
Also there is evidence that medium sized predators were outcompeted by the larger predators such as Trex during the late cretaceous, so it makes sense that there wouldn't be too many off shooting (smaller) species of T Rex overlapping during that time span. Probably only very specialized medium/small carnivores that did not directly compete with T Rex. I really think T Rex could only be successful as it exists in it's large form. Anything else probably couldn't compete with other predators that filled the niches the large T Rex didn't already fill or other medium predators couldn't already fill either
@@brandonaldaymachuse6669 No, isolation could still lead to different species. I could imagine a dwarf species of tyrannosaur on an island somewhere, but having that dwarf species be fossilized and having that fossil be discovered might be a tall order.
@@christosvoskresye There are actually many different species of Tyrannosaurs, it was a fairly large and diverse family. However, there is (currently) only 1 species the the genus Tryannosaurus and that's the rex.
I say a more likely scenario is that they may have represented two populations (with a degree of overlap) that evolved some traits based on different environmental pressures without necessarily speciating. We have lots of examples of animals within the same species that look very different depending on their regions (leopards in Africa have two size morphs, so to speak, the larger one occurs in regions where lions do not, with the opposite being true for the smaller one). Despite this, they are still considered the same species. This is assuming that these do represent distinct morphs and not simply individual variation.
I have been so looking forward to this, and as always Ben does not disappoint! I do wish we could move beyond the idea that any single paper, no matter how immaculate the research, could ever be definitive of anything. Of course the reporting by news outlets only aggravates the problem. I also wish new ideas weren't perceived as attacks on the "authority" of more established, or specialised, researchers. The very need to be constantly fighting for funding, fighting for opportunities, or access to specimens, has further ingrained an adversarial culture in all fields of science, and I feel as though we all lose out as a result. But that's just the perspective of an enthusiastic no-nothing looking in.
Bingo! Additional funding is what this all really boils down to. Nobody gets the interest & buzz flowing, with simply more of what we have already discovered & named, but all new discoverys with all new names attached, certainly does. Not sure how funding & grants actually work, & im definately no wild conspiracy nutjob, but something about all this seems at the very least, odd, seeing how these companies who make dinosaur toys & collectables, already have plans on the drawingboard, to make & sell these newly named Tyrannosaurs.smh As if the abysmal track record called latest scientific evidence, needs (yet another) soon to be obsolete & disproven L to wrestle with. Confound you new & recent Spinosaurs! Are YOU whats behind all this bullshite? Or is it Mattel lol
While I am still a bit skeptical of this paper proposing that there were actually three species of Tyrannosaurus instead of just one, I am thankful that you answered a few questions I had regarding the paper: -I originally thought the three species of Tyrannosaurus coexisted with each other during the same time/place. Now I'm aware that it was one species (T. imperator) that evolved into two (T. rex & T. regina) as time progressed. -While anatomical differences, niché partitioning (T. rex primarily hunting Ceratopsians, while T. regina mainly hunted Hadrosaurs?) & past/modern analogues are things you've mentioned the paper included as supporting evidence; there's another possible modern analogue I'd like to mention. There are two (technically three but the Indian Leopard is actually a mesopredator) species of Panthera that both live in India; the Bengal Tiger & the Asiatic Lion. Both big cats are apex predators that hunt similar prey but are able to coexist with each other because they live in different habitats (The Bengal Tiger living in dense forests, while the Asiatic Lion lives in semi-open grasslands). Maybe it was a similar situation for T. rex & T. regina?
That is an interesting and certainly plausible analogy, the only issue is that there’s no real evidence for these particular new species. Plus, unlike any modern predator that I know of, Tyrannosaurus managed to fill many different niches as they slowly matured. Even if the evidence was sound, the design of the paper and the attitude of the main author are both… questionable at best. It would make sense for there to be a northern species and a southern species, but that’s entirely speculation on my part.
What is the evidence that tyrannosaurs filled different niches as they slowly matured? That makes sense logically, but is there evidence for it? Also, what are the scientific estimates for how long these creatures lived, assuming they didn’t die early?
As far as I know, Bengal tigers and Asiatic lions don’t overlap. Asiatic lions are limited to the Gir Forest in Gujarat, and rarely ever overlap with other tiger subspecies.
@@fleetskipper1810 multiple osteohistology studies have looked at the bone structure of multiple Tyrannosaurus rex specimens, including all known juvenile specimens, and found that T. rex took around 20 years to mature, and that the rapid shift in body shape during the last growth spurt almost certainly indicates a different niche held by the faster, narrow-mouthed juveniles. The main study was published on January 1, 2020.
@@fleetskipper1810 Different ecological niches occupied by the same speices separated by age does exist in nature. Crocodillians are a good example of this, as hatchlings they primarily eat insects & small fish, as they get older (depending on species) they move up to larger and larger prey until they're preying upon largel land mammals. Great whites are like that too, when they're young, they're earting mostly fish, but as they get older and bigger they transition to marine mammals. However, in both of these cases, they really aren't exlcusive to these niches, lots of other predators around that eat small things, and plenty or predators that eat large things. As for evidence, I think that's hard to prove right now. Unless we find a lot more spcimens with gut contents or our tech gets better at reading trace minerals to deremine what a T. rex primarily ate, I'm not sure that there's any way of determing if young and old Tyrannosauruses occupied separate ecological niches or not. But the genral lack of medium predators during the time and lcoales of T. rex does seem to suggest that maybe young and old Tryannosauruses did oiccupy separate ecological niches.
I'm going to side with what most Tyrannosaurus experts are currently stating. Tyrannosaurus rex is just Tyrannosaurus rex. The very little distinguishable elements used in the study to split Tyrannosaurus into 3 speices can easily be explained through simple variation within a speices. The paper while interesting is really really flawed there is just not enough evidence put forward to justify the split. Something you did not mention is the main author for the study Geg Paul has a history of always splitting taxa something he is often criticised for his taxonomy is really bad. Apparently this study was rejected twice in peer review by Thomas Holtz and further more Phill Currie who worked on the paper has distanced himself from it entirely. Maybe in time we will get a study that actually does a good job with providing a good argument for splitting Tyrannosaurus and has better evidence to support the hypothesis but Greg Paul's work here is highly questionable.
And renaming and moving species as he saw fit. The infamous JP velociraptor thing stems from him when he moved deononychus into the velociraptor genus name. Paul is almost hacky with his schtick.
The Tyrannosaurus regina was about the size of a T-Rex called Sue. But Sue was probably older.Tyrannosaurus imperator was slightly smaller than T-rex Scotty
I raise you this If these two are not different then what about the velociraptor mangas and velociraptor Mongoliansas (there is a third one that I forgot what it was called) which have like very little difference that is really noticable like the fact that mangas had a flatter head I'm not trying to be aggressive (I can't really tell when I sound aggressive) but I'm just pointing out that little features has created different species That's also the same reason there was a debate between the difference between a baryonyx and the suchomimus and if they were different or the same dinosaur.
@@24packofcrayolabrandcrayon74 there have been a lot of paleontological revisions to reduce species and genus numbers. Way more than there ever have been to split animals into more varying species. This was especially true once paleontologists started to scrutinize the works of marsh and cope but even to this day it is happening. The Torosaurus is a triceratops male and the pachycephalosaurid retraction are just two of the most famous debates going on to reduce genus and species numbers. It would not surprise me if velociraptor gets that scrutiny in the future as well.
I find it more likely that t.regina and rex are either growth stages, or sexual dimorphism. Buuuut it is possible. I think one thing that would help prove this is geographical overlap. The t.imperator split makes sense however.
Possible but there are stratigraphic constraints. I mean we do see anagenesis particularly with Daspletosaurus. But more likely its a combination of individual variation and variation over time.
This is very similar to the situation of multiple unique spinosaurid taxa in North Africa. Both are possible, but not nearly enough evidence to support either.
There being multiple Spinosaurids, Carcharodontosaurids, and Abelisaurids is likely due to the span of time the Kem Kem Group and Dekkar Group represent. 2/3 of the formations within the Kem Kem produce terrestrial vertebrates with the Akrabou being marine.
This is a very interesting (if not controversial) paper. On one hand I can see the idea that Tyrannosaurus had multiple separate species in the genus, but on the other hand there is not enough evidence in the paper to confirm it. Like if we find a Tyrannosaur specimen with a longer snout, that could be evidence (That’s the main difference between Tarbosaurus and Tyrannosaurus.)
It seems likely to me that most dinosaur Genera had multiple species (since most animals today have) but its very difficult to have a sample size large enough to really show this. The evidence here is interesting but doesn't seem very conclusive.
Great explanation. It's still so strange that fewer specimens are used to describe new species... Like a catch-22, if you have a lot of samples you can see the variability, but if you have very few samples or only one then it's a new species because there's no variability to fit it within.
T-Rex is held to a higher standard than other species. This is because we have a lot of good skeletons, because we have done a lot of research, and because the dinosaur has a lot of fans.
First time I ever heard the name "Tyrannosaurus Imperator" was when it was being discussed as a possible name for a T-Rex specimen discovered by Dr. Keith Rigby. The reason they were opting for the name "Imperator" was because this T-Rex was supposedly the biggest T-Rex ever discovered and was rumored to measure somewhere around SIXTY-FIVE feet long!
@@symphonyofshred I said "supposedly". It turned out this Rex was more like 48-50 feet. I believe it's the one that was named "Peck's Rex" (that Rex might also be the one called "Scotty", I can't remember).
Scotty is 43 feet long, slightly bigger than average, UCMP 137538 is 15.5-16 meters long, and MOR 1126 is rougly 14-15 meters long, so either you're talking about a Rex I haven't heard of, or you're likely talkin about UCMP 137538 or MOR 1126
I think the possibility remains, though we'll still need more definitive evidence. Consider modern avian dinosaurs, there are many genera that each contains multiple similar yet distinct species, with the primary non-DNA methods to distinguish them being differences in plumage coloration and/or slight body size differences. Some examples are Corvus, Passer, Aquila, and Haliaeetus, to name a few. Either way, this is a really interesting paper and it's definitely fun to imagine that even with just the dinosaur genera we have discovered so far, they may still represent more diversity than previously thought! Tyrannosaurus species with different skin colors and plumages (if present)!
This makes me think of all the variations of jay birds and how they only slightly vary from one another( like minor changes to the size and shape of the beak to different shapes and colors to plumage). They are all considered to be jay birds but are considered different species of jay birds because of those minor changes.
4:17 Fun fact about this picture: This is Black Beauty, displayed at the Royal Tyrell Museum in Drumheller, Alberta, just four hours drive east of me. The curators had this posed the way it was found, but to do that they had to use a fake skull made out of cast because the T-rex's skull was far too heavy. The actual skull is on display too and is near the feet of the skeleton. It's so weird for me to see many of the photos you use come from a place so close to me (and my heart). Anyone who hasn't visited Drumheller is missing out!
Given what we know now about how quickly species can evolve compared to what we used to think 100 years ago, I think it’s unreasonable to think that T. Rex did not evolve significantly over the span of a couple million years. On the other hand, scientific proof, as you pointed out, is very hard to come by. I think that this paper opens up new vistas for discussion, though.
Thanks for covering this issue. Another thing to note is that, even if these three species were valid, they likely wouldn’t be given brand new names. Plenty of older, now obsolete names were given to various rex specimens upon their discovery, and these would take priority. It’s possible the author just wanted to quickly get to name two new tyrannosaurus species before anyone else.
What is hilarious is that one of the main author’s previous names likely takes precedence over T. regina = Paul seems to have forgotten that he named one of the regina specimens as the holotype of Albertosaurus megagracilis in 1988 so T. megagracilis should have priority.
I hate to do this to you Ben but I have to tell you that the definition you gave for species (at about 1:10?) is highly debatable even amongst biologists these days. A good example of why that definition doesn't really work that well is that grizzlies and polar bears have started interbreeding relatively frequently in the wild over the past couple of decades. I can't remember how fertile their offspring are however. It would seem to me that the term "breed" may need to slightly redefined for use as scientific vernacular. It's not a very pleasant word, but I think it's the best description for the extinct "species" of humans that our ancestors intermingled with as well.
He did say we have a "fairly good" idea of what defines a species, which we do. Not perfect, and could stand refining, but good enough that it usually works.
Another one that comes to mind is the grey wolf, eastern wolf, red wolf, coyote complex(and toss in domestic dogs for good measure). Those animals can all interbreed with completely fertile offspring the result. By the base definition of species...that would make all of those animals the same species, perhaps "races" of a single species. Indeed there is a wide belief that red wolves and perhaps eastern/timber wolves are the result of coyote/grey wolf hybridization, and there is also strong indicators of a "mystery" canid in the mix that also was/is completely cross fertile.
@@NightwingGR1 you can add to that list the dingo, sometimes _Canis dingo_ sometimes _Canis familiaris dingo_ sometimes _Canis lupus dingo._ Another possibility, especially with the point made near the end about Tyrannosaurs' robustness possibly being more of a spectrum and less polarised as initially thought, is a ring species. Something where defining the borders of "species" would be difficult even if we could look back and have full knowledge of what they were like at the time.
I know Regina means queen in Latin but I like that it is also the name of Dino Crisis main character, it's kind of ironic since she gets attacked by a T. Rex lol.
There's also the possibility that there could have been two or three distinct populations that occasionally hybridized, but perhaps they were more subspecies than distinct species.
Well, after watching all of this, with the new names: Imperator and Regina added to Tyrannosaurus, this amount of evidence is still very new, as for over a century, we been so used to the name Rex, but as long as they're all Tyrannosaurus, I don't appear to mind, though I always be a life long fan of the dinosaur for years to come.
Pretty well every paleontologist asked has said although it's perfectly possible, there's just not enough evidence at the moment. I think the video here nailed it; it was done more for publicity than anything else. Greg Paul has form at this kind of thing
In an article I read about this, it stated that the authors of the paper, said that it is possible that these differences may only be individual variation or sexual dimorphism, which makes sense this is only a proposal, a theory if you will which even the authors question themselves.
Given that Orcas have different species that only differ in habitat, diet and behaviour it could be very likely that the Tyrannosaurs did behave differently and had some corresponding physical differences. I think it would make sense but I doubt we'll ever get a accurate answer :(
Kind of like how there are 4 current species of giraffe. How important is the distinction really about extinct animals between very closely related species and subspecies
@@SoulDelSol The 4 recently recognised species of giraffe have vastly more pronounced skeletal differences between each other vs the flimsy characters that Paul is proposing for his 3 separate Tyrannosaurus spp. For example Lee. et al 2022 demonstrate substantial differences in the foot bones (fibula, calcaneus, and astragalus) between Giraffa camelopardalis and Giraffa reticulata.
@@nutyyyy if you're talking to me there are 4 species of giraffes confirmed through dna plus multiple additional subspecies. Even with these living animals there has been confusion and disagreement with this up until dna was done. As for orcas I'm not sure but i wouldn't be surprised if there were both.
@@Ozraptor4 oh i agree, this proposed paper seems flawed. Like he just wanted to name them himself or something. There is very little distinction between proposed t rex spin offs and seems like it's just one researchers attempt to make a name for himself rather than supported by actual robust evidence
I LOVE y'all's depth of coverage of all the paleontology news. I've been a subscriber for at least 2 years and it's just continually and increasingly impressive.
The 'robust vs.gracile' argument doesn't convince me to be honest. Compare the femurs of an average rugby player with an average football (soccer) player and I guarantee you would see enough of a difference in thickness to genuinely believe they are 2 distinct species if you didn't already know they were just the femurs of 2 humans. A better modern example would be the okavongo delta lions which are absolutely enormous, just because they live alongside a lot of buffalo. Very interesting ideas brought forward though, great video all in all.
It would be interesting that what's happening is how a bobcat and the Canadian lynx are almost indistinguishable. They're all lynxes but are significantly different enough to be their own species.
There are probably many species that can not be distinguished from each other with only fossil remains. But the larger the species, the smaller the probability.
@@MithriVideolari Maybe. I think the only true way to prove anything about fossils is to actually see the living creature. A sample, a corpse or as it is now, a fossil, can only reveal so much. Even today species that are alive are getting put into their own subspecies or an entirely different genus due to how they behave, or whatever, making the creature distinct enough to those like it.
Meanwhile everyone does say it could be dubious the fact that speciation happens all the time as well as the conditions of N America was perfect for Speciation to occur in mid to late cretaceous! Like Grizzly Black and Polar bears for example! Also The Torosaurus is definitely a different ceratopsian now where a recent study indicate or validated their young subadult fossils discovery
@Leo the Anglo-Filipino Indeed alas until a very few years ago all central slender snouted crocodiles deemed the same species now its totally the opposite same for the primates
It's possible that some of what we currently consider to be T. rex may represent different species, the problem is that the authors did a very poor job presenting their case, which is what really matters in this case.
Of course it’s highly possible that Tyrannosaurus includes more species than just rex, but the criteria provided in this paper are just not it for me and many others.
These creatures existed for hundreds of millions of years and then disappeared the truth is they developed and created space travel and are still among us today the history channel doesn't lie
personally, i feel as though there are multiple species of tyrannous that we haven't discovered yet, however the paper here doesn't use enough predominant differences to truly be able to classify them as different species, rather individual variation or genetic malfunctions, considering the fact that most of the differences here are too minor to really leave impact, the femur sizes can easily be because of age or individual variation, most of the claims in this paper rely heavily on pedantry and incredibly minor details that aren' very meaningful
Judging by the bones alone a chihuahua, a pitbull and a golden retriever are separate species. Male and female elephant seals will also be considered separate species based on the bones alone. So... Before jumping to conclusions I believe we will need more and more reliable data.
Great video, Ben. Just to correct one thing you said - even in contemporary biology, the species definition issue is not simple at all, and there are lots of grey areas where some of the more common definitions don’t align with actual defined real world species. And that’s the benefit of DNA analysis and real world specimins to deal with!
We've got the same problem in Paleoanthropology with the H. bodoensis proposal. Lots of debate as to if it should be labeled a new species or not. I think it has been recognized since the paper was first published late last year, but many of us still don't necessarily think it should be classed as a new species.
Couldn't this just be regional variations on the same species? The same species of an animal after all tend to vary dependent on the kind of area or location in the world and often develop certain unique traits but are still the same one.
To show how shoddy the paper is = In 1988 GSPaul named Albertosaurus megagracilis with the holotype LACM 28345 (now almost universally considered a sub-adult T. rex). Now in 2022, he erects Tyrannosaurus regina and assigns this specimen to it, with no mention of his previous nomenclature. If LACM 28345 is diagnostic enough to be assigned to T. regina, then T. regina is a subjective junior synonym of Paul's own T. megagracilis.
Great summary of this topic. Very fair and true to the facts. It got me thinking of something which I didn't read or hear pointed out elsewhere: Maybe the greater variation in femur proportions can be explained by the size of T. rex? This species could grow a couple of times heavier than the other tyrannosaurs and Allosaurus. The variation in absolute mass ought to be bigger than in these taxa. Sure, a smaller species may be more heterogeneous, but this can be checked in a principal component analysis of some sort
As far as I'm thinking, if three potential triceratops species. More or less stratigraphically separated, may have existed, according to the law of co-evolution. At least to me it doesn't appear that strange that a similar pattern may have been case for the tyrannosaurus-genus. Especially when taking into account the prey and predator-relationship between the two.
The degree of co-evolution which occured between tyrannosaurs and ceratopsids never ceases to amaze me. While it is inaccurate to attribute intent to the evolutionary process, it honestly comes across almost like an arms race between jaws and horns, teeth and frills. While it is likewise inaccurate to apply some terms to animal taxa, if there were any two groups of animal which deserved to be called rivals, it was the tyrannosaurs and ceratopsians. It is perhaps fitting that the (non-avian) Dinosaurs weht extinct when both "factions" reached their zenith. Regardless of such baseless, indulgent romantics, I do think you have a good point. It seems at least a fair consideration to use the two (three?) species of Triceratops as analogy to possible speciation of Tyrannosaurus, based on the established co-evolution between their taxonomic groups.
Would those variations point more towards subspecies rather than speciation? Like, subspecies are the same species, just different enough in some way to be distinct. Like, look at yellow belly sliders and red ear sliders. Same species but ybs are a subspecies with a unique phenotype
The nightmare comment reminded me that while I have never had a nightmare about Tyrannosaurus, I have had one where a pair of Deltadromeus systematically took apart my house wall by wall, trying to get to me. I might be the only person to have one about that taxon, lol.
One of the specimens assigned to T. regina happens to be the "Dinotyrannus megagracilis" holotype, so even if the authors are correct in their assessment, the taxonomically correct name for this proposed taxon should be "Tyrannosaurus megagracilis".
I love how we could potentially have this line up of one of the most iconic intimidating animals in media/history Rex - 🦖🦖🦖🦖 Imperator - 🦖🦖🦖🦖 Regina - 🦖🦖💅💅🦖🦖
I have the Princeton Field Guide to Dinosaurs by Paul from 2016 and there are two potential species of Tyrannosaurus mentioned: an unnamed robust species and T. rex. So it’s interesting that this idea made it into a paper now. Also get ready for the "everything belongs to Centrosaurus" paper :D
I'd say the evidence is still far from compelling, but worth further research. I hear Horner is planning a paper on how T. Rex is a species of ceratopsid.
Check Paul's resumee (one of the authors of the paper), he loves naming new species for the sake of it, based on limited or unconvincing evidence. Several of his proposed species are considered invalid or dubious. He seems like an attention seeker who just wants to be talked about.
This. I don't mind the proposal of more than one Tyrannosaurus species if it were well sustained with evidence, but the author's reputation and indeed the frail evidence presented makes me think the lad just wants to stir things up for the sake of it. I mean, just look at the grandiose names he came up with FFS! The whole thing feels very "History Channel-y" to me: "I'm not saying a̶l̶i̶e̶n̶s̶ several Tyrannos but yeah a̶l̶i̶e̶n̶s̶ several Tyrannos"
I feel this is a great example of how the 'species' model of classifying life forms doesn't make much sense. Nature is not logical and has no obligation to conform to our own logical frameworks. When it comes to 'species' - they are not fixed, easily defined things and they never were. Life forms are unfixed, changing, dynamic, open systems weaving through time, their morphology and genes morphing and shifting with the environment. Life acts more like a fluid flowing downhill than it does a discreet collection of easily definable categories. It is our own tendency to obsessively categorize and fragment the world into an ever increasing number of bits and pieces which is the issue.
This is a very intriguing proposal, but I'd rather wait and hear for more evidence on it. At this point, I wouldn't be surprised if this ended up being true, considering how much paleontology has changed/expanded over the years.
I hope they'll stay with T-rex... Just because T-rex is the poster boy of paleontology, it helps with vulgarisation because everyone seems to have a crush on it. Just like we didn't decide to call it Massospondylus giga, even if we're supposed to, it would be better in terms of "marketting" for paleontology to have only T-rex.
Superb! Very thorough and thoughtful presentation of what science should be: continually questioning and not settling on premature proclamations. Even if there is only one species of T. rex, it is far better to analyze the minutiae of the limited evidence than to make bold assumptions. What happened to Doug? Did he suffer the fate of those poor souls at 11:48 and lost his mind? Get well soon, Doug!
Can T.Regina and T.Rex be just *subspecies*? Maybe there’s just Tyrannosaurus Rex, that descended from T.Imperator and one subspecies that is Rex Regina and another that is Rex Rex; just like it happens with tigers, if we apply these same techniques to separate species we could get almost about 8 new species of Panthera, that are actually different subspecies of P.Tigris.
I don't think that they can consider them sub-species, because we can't see their living differences, if I had to guess, however, you're absolutely right that that could be the case
From what I got from this video, it sounds like the more significant point is that the dentition changed from older to newer specimens, & the genus developed the robust & gracile forms later as well. It sounds to me like the researchers were overly concerned about the data they had about the robustness & rex vs regina.
I have to disagree with naming two different species...that's really not taking into account the variability between individuals. It's even jumping over subspecies and going straight into two different species. I think this was way too early of a jump to even come close to with such a small number of specimens. The variation could very well be just based on different sexes.
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
"You forgot that the year was 2022 and anything can happen at this point."
Man I felt that
On a bright note, we got the Torosaurus paper soon after, which thankfully debunked some old trash instead of creating new trash.
Red Raptor Writes in the comments, incredible. A crossover between these 2 channels would be legendary
I was surprised by that statement. Why did he say it?
What if Titanoboa came back despite everyone saying it couldn't?
@@Pumpkin525 i hope purrusaurus comes back too. Itd be a hell of a movie
Without a significant sample size and very distinctive differences to use as exemplar, it is basically impossible to tell if these variations are individual-to-individual or species-to-species ones. I mean, there is still a debate over whether certain smaller "T.Rex's" are smaller species, younger representations, or even separate species that are not T.Rex.
Didnt you hear? They found half a sliver of a fossilized toenail recently. Of course we get all new Tyrannosaurs. You didnt think they would call it a boring Sauropod, did you?
Nanotyrannus was a proposed genus of small Tyrannosurids, however, it was later realised that it was a juvenile T. Rex. Tyrannosaurs had such a monopoly as apex predator that the niche of medium sized carnivore was filled by younger Tyrannosaurs.
@@juanjoyaborja.3054You are correct, nanotyrannus are juvenile and subadult tyrannosaurids, but of what is still debatable.
Well, the line between species is somewhat arbitrary to begin with.
The only reason its so easy to draw that line with (most) modern day animals is because all the transitional forms that connected them have died out.
Just look at the age old debate on where our own ancestors "stopped being 'just apes' and started being human".
@@juanjoyaborja.3054 I know there's no evidence of mid sized carnivores sharing T.Rex environment and time period but that doesn't mean they didn't exist...
Can fossil specimens be designated as subspecies, or is that only possible for living organisms? It seems certainly possible that there could be distinct morphs of Tyrannosaurus, but not enough to actually warrant splitting the species.
I don't think so, the best you can do is suggest a chronospecies/ancestral species as is implied with Tyrannosaurus imperator in this paper. If you can get some genetic information sure. But subspecies, and even different species of the same genus may not be distinct anatomically. A lot of these Tyrannosaurus rex specimens could have looked different on the outside, but unfortunately there's no way we will ever know. At least, not in any formations where Tyrannosaurus occur.
Subspecies are defined by DNA typically.
Fossil subspecies can be named if you have a HUGE sample size of individuals (10,000s) and the very slight differences are consistent and unambiguous. Happens with many marine invertebrate taxa (brachiopods, bryozoans, conodonts, foraminifera etc.)
In living animals, sometimes even different species are only really able to be identified through soft tissue and/or DNA. I can't think of it now, but I feel I've heard of modern animals often used to tests undergrads studying bone structures due to the two species having almost identical skeltons (and if memory serves, it is two related animals but not ones you would mistake for the same species of you saw them in the flesh - think, like, Leopards and Tigers. Those are not the species I'm thinking off, but imagine for a minute that, given only their skeletons it took an amazing attention to detail and a full knowledge the same handful of differences to be able to correctly identify which was which, when given the two living animals any first grader is able to spot the difference.)
Knowing this to be the case in certain living species, it's not difficult to imagine that an animal that lived over such a large chronological range may have had many different subspecies and even species. But it could be the majority of changes were to the soft tissue, behavior, or other factors that we are unlikely to be able and catalog based on fossils alone..
That has been suggested for some of our near relatives, particularly Neanderthals, so the idea that it CANNOT be done for fossil animals is false. In fact, I'm pretty sure the suggestion was made before DNA was recovered and analysed.
Honestly, whether we're talking about species or planets, nature tends not to divide things nicely into well-defined categories for us. That's not to say there are no boundaries, but the optimal place to put them is hard to define. The mass of Pluto can be scientifically measured, as can its orbit; whether we choose to call it a planet is more about us than about Pluto. It's much the same with some of the species/subspecies questions.
Please make a video on how animals convergently evolved their horns/antlers multiple times, independently 🙏
And don't forget ossicones.
you mean convergent evolution?
@@victzegopterix2 Ooh yeah 👍
That just bounced off my mind
What if different species were the same species but with differing growth scales depending on age, a bit like a cassowary.
@@Scoobywoo7447 no bro..!!
I'm taking about animals like cow, rhino, deer, giraffe etc. Even triceratops could also be in this list.
I think you got it, you are smart enough!
So far it seems pretty spurious to me. Another palaeontologist not on the team said he thought the team had set out to see if the known T. rex fossils could be split into separate species, and lo and behold, they did. They saw what they wanted to see, in his words.
The paper is not very convincing, but to be fair they set out to see IF they could recognize different species, not to MAKE them such.
Gotta love when that confirmation bias creeps into the sciences, which it always seems to do (unfortunately).
@@eudyptes5046 they DID make new species though, complete with holotypes and zoobank registrations.
One thing must be mentioned about this paper. Gregory S. Paul is involved. Now for people who don't know, Paul is a famous dinosaur artist who likes to think he is a Paleontologist. He is a really talented artist, but he has no doctorate.
Now Paul is also famous for another thing. The man loves to try to destroy established genus names. The whole thing about Deinochyus being an invalid taxon to Velociraptor? That was his doing in his "Predatory Dinosaurs of the World" book. He has also tried to eliminate many other names including Coelophysis, and most notionally for here, Tarbosaurus. He has for decades now considered Tarbosaurus just a species for Tyrannosaurus, something that was not peer reviewed, and has kept putting this little detail in the various books he has written.
So here's the big thing here, this new paper he is attached to, is also an attempt to strengthen and legitimize what he did to Tarbosaurus. I can see why Philip Currie retracted his name from it.
Unfortunately this happens a lot in science, especially in areas that have politicized. It's very hard, and maybe even impossible to find an unbiased study in regards to the future climate, and has been like that ever since climate change has been politicized by the like of Al Gore who have made millions off of it. (I'm not saying climate change doesn't exist, just that the issue is now far more political and biased then it is actual science).
"T. Regina"
As a Dino Crisis fan, it makes me soooo happy that name was used for a newly discovered dinosaur.
Truly amazing.
Was thinking the exact same thing! That was my first thought when I saw the name haha
@@KamiKaze43v3r It was impossible to not think about it hahahah
We need a dino crisis remake so bad.
@@alexandercatz5214 True that.
Except it's not a newly discovered dinosaur, all the T-Rex experts and paleontologists disagreed with this paper, there just isn't enough evidence and the differences aren't enough to be whole new species
I love that you present ideas, good or bad, to get discussion and imaginations going. Keep it up.
It'd be cool if there were more than one Tyrannosaurus species, but from the sound of it, the paper in question doesn't present that great of an argument. Kind seems like there's more evidence for multiple species of Spinosaurus. Now I wouldn't be surprised if more than one Tyrannosaurus species did actually exist, but I don't think we're at a point where just looking at the bones could prove it.
Also there is evidence that medium sized predators were outcompeted by the larger predators such as Trex during the late cretaceous, so it makes sense that there wouldn't be too many off shooting (smaller) species of T Rex overlapping during that time span. Probably only very specialized medium/small carnivores that did not directly compete with T Rex. I really think T Rex could only be successful as it exists in it's large form. Anything else probably couldn't compete with other predators that filled the niches the large T Rex didn't already fill or other medium predators couldn't already fill either
Not to mention theres birth defects and deformities, which can impact bone structure
@@brandonaldaymachuse6669 No, isolation could still lead to different species. I could imagine a dwarf species of tyrannosaur on an island somewhere, but having that dwarf species be fossilized and having that fossil be discovered might be a tall order.
@@christosvoskresye There are actually many different species of Tyrannosaurs, it was a fairly large and diverse family. However, there is (currently) only 1 species the the genus Tryannosaurus and that's the rex.
Don't forget about Tarbosaurus, it's part of the Tyrannosaurus section in it's family.
I say a more likely scenario is that they may have represented two populations (with a degree of overlap) that evolved some traits based on different environmental pressures without necessarily speciating. We have lots of examples of animals within the same species that look very different depending on their regions (leopards in Africa have two size morphs, so to speak, the larger one occurs in regions where lions do not, with the opposite being true for the smaller one). Despite this, they are still considered the same species. This is assuming that these do represent distinct morphs and not simply individual variation.
I have been so looking forward to this, and as always Ben does not disappoint! I do wish we could move beyond the idea that any single paper, no matter how immaculate the research, could ever be definitive of anything. Of course the reporting by news outlets only aggravates the problem. I also wish new ideas weren't perceived as attacks on the "authority" of more established, or specialised, researchers. The very need to be constantly fighting for funding, fighting for opportunities, or access to specimens, has further ingrained an adversarial culture in all fields of science, and I feel as though we all lose out as a result. But that's just the perspective of an enthusiastic no-nothing looking in.
All very true.
Bingo! Additional funding is what this all really boils down to. Nobody gets the interest & buzz flowing, with simply more of what we have already discovered & named, but all new discoverys with all new names attached, certainly does. Not sure how funding & grants actually work, & im definately no wild conspiracy nutjob, but something about all this seems at the very least, odd, seeing how these companies who make dinosaur toys & collectables, already have plans on the drawingboard, to make & sell these newly named Tyrannosaurs.smh As if the abysmal track record called latest scientific evidence, needs (yet another) soon to be obsolete & disproven L to wrestle with. Confound you new & recent Spinosaurs! Are YOU whats behind all this bullshite? Or is it Mattel lol
Very true. It is hard to be definitive with dinosaurs, because we don’t have time machines.
While I am still a bit skeptical of this paper proposing that there were actually three species of Tyrannosaurus instead of just one, I am thankful that you answered a few questions I had regarding the paper:
-I originally thought the three species of Tyrannosaurus coexisted with each other during the same time/place. Now I'm aware that it was one species (T. imperator) that evolved into two (T. rex & T. regina) as time progressed.
-While anatomical differences, niché partitioning (T. rex primarily hunting Ceratopsians, while T. regina mainly hunted Hadrosaurs?) & past/modern analogues are things you've mentioned the paper included as supporting evidence; there's another possible modern analogue I'd like to mention. There are two (technically three but the Indian Leopard is actually a mesopredator) species of Panthera that both live in India; the Bengal Tiger & the Asiatic Lion. Both big cats are apex predators that hunt similar prey but are able to coexist with each other because they live in different habitats (The Bengal Tiger living in dense forests, while the Asiatic Lion lives in semi-open grasslands). Maybe it was a similar situation for T. rex & T. regina?
That is an interesting and certainly plausible analogy, the only issue is that there’s no real evidence for these particular new species. Plus, unlike any modern predator that I know of, Tyrannosaurus managed to fill many different niches as they slowly matured. Even if the evidence was sound, the design of the paper and the attitude of the main author are both… questionable at best. It would make sense for there to be a northern species and a southern species, but that’s entirely speculation on my part.
What is the evidence that tyrannosaurs filled different niches as they slowly matured? That makes sense logically, but is there evidence for it?
Also, what are the scientific estimates for how long these creatures lived, assuming they didn’t die early?
As far as I know, Bengal tigers and Asiatic lions don’t overlap. Asiatic lions are limited to the Gir Forest in Gujarat, and rarely ever overlap with other tiger subspecies.
@@fleetskipper1810 multiple osteohistology studies have looked at the bone structure of multiple Tyrannosaurus rex specimens, including all known juvenile specimens, and found that T. rex took around 20 years to mature, and that the rapid shift in body shape during the last growth spurt almost certainly indicates a different niche held by the faster, narrow-mouthed juveniles. The main study was published on January 1, 2020.
@@fleetskipper1810 Different ecological niches occupied by the same speices separated by age does exist in nature. Crocodillians are a good example of this, as hatchlings they primarily eat insects & small fish, as they get older (depending on species) they move up to larger and larger prey until they're preying upon largel land mammals. Great whites are like that too, when they're young, they're earting mostly fish, but as they get older and bigger they transition to marine mammals. However, in both of these cases, they really aren't exlcusive to these niches, lots of other predators around that eat small things, and plenty or predators that eat large things.
As for evidence, I think that's hard to prove right now. Unless we find a lot more spcimens with gut contents or our tech gets better at reading trace minerals to deremine what a T. rex primarily ate, I'm not sure that there's any way of determing if young and old Tyrannosauruses occupied separate ecological niches or not. But the genral lack of medium predators during the time and lcoales of T. rex does seem to suggest that maybe young and old Tryannosauruses did oiccupy separate ecological niches.
I'm going to side with what most Tyrannosaurus experts are currently stating. Tyrannosaurus rex is just Tyrannosaurus rex. The very little distinguishable elements used in the study to split Tyrannosaurus into 3 speices can easily be explained through simple variation within a speices.
The paper while interesting is really really flawed there is just not enough evidence put forward to justify the split. Something you did not mention is the main author for the study Geg Paul has a history of always splitting taxa something he is often criticised for his taxonomy is really bad.
Apparently this study was rejected twice in peer review by Thomas Holtz and further more Phill Currie who worked on the paper has distanced himself from it entirely. Maybe in time we will get a study that actually does a good job with providing a good argument for splitting Tyrannosaurus and has better evidence to support the hypothesis but Greg Paul's work here is highly questionable.
And renaming and moving species as he saw fit. The infamous JP velociraptor thing stems from him when he moved deononychus into the velociraptor genus name. Paul is almost hacky with his schtick.
@@scottb3034 Yup
The Tyrannosaurus regina was about the size of a T-Rex called Sue. But Sue was probably older.Tyrannosaurus imperator was slightly smaller than T-rex Scotty
I raise you this
If these two are not different then what about the velociraptor mangas and velociraptor Mongoliansas (there is a third one that I forgot what it was called) which have like very little difference that is really noticable like the fact that mangas had a flatter head
I'm not trying to be aggressive (I can't really tell when I sound aggressive) but I'm just pointing out that little features has created different species
That's also the same reason there was a debate between the difference between a baryonyx and the suchomimus and if they were different or the same dinosaur.
@@24packofcrayolabrandcrayon74 there have been a lot of paleontological revisions to reduce species and genus numbers. Way more than there ever have been to split animals into more varying species. This was especially true once paleontologists started to scrutinize the works of marsh and cope but even to this day it is happening. The Torosaurus is a triceratops male and the pachycephalosaurid retraction are just two of the most famous debates going on to reduce genus and species numbers. It would not surprise me if velociraptor gets that scrutiny in the future as well.
I find it more likely that t.regina and rex are either growth stages, or sexual dimorphism. Buuuut it is possible. I think one thing that would help prove this is geographical overlap. The t.imperator split makes sense however.
Possible but there are stratigraphic constraints. I mean we do see anagenesis particularly with Daspletosaurus. But more likely its a combination of individual variation and variation over time.
They likely are. This paper barely mentions ontogeny
100% agree.
@@ferociousrazordino3581 Yeah I thought that was strange. I mean, we've been through something similar with Yutyrannus.
The slender ones could also just be smaller malnourished ones.
This is very similar to the situation of multiple unique spinosaurid taxa in North Africa. Both are possible, but not nearly enough evidence to support either.
The spinosaurids seem to be much more diverse as anything among T.Rex.
There being multiple Spinosaurids, Carcharodontosaurids, and Abelisaurids is likely due to the span of time the Kem Kem Group and Dekkar Group represent. 2/3 of the formations within the Kem Kem produce terrestrial vertebrates with the Akrabou being marine.
@@paleozoic A hard rock group has multiple different spinosaurids? That's weird.
@@TheZinmo Not really, most lines favoring multiple taxa is mostly due to misidentified or terrible preservation of fossils.
In the kem kem beds that is.
This is a very interesting (if not controversial) paper. On one hand I can see the idea that Tyrannosaurus had multiple separate species in the genus, but on the other hand there is not enough evidence in the paper to confirm it. Like if we find a Tyrannosaur specimen with a longer snout, that could be evidence (That’s the main difference between Tarbosaurus and Tyrannosaurus.)
It seems likely to me that most dinosaur Genera had multiple species (since most animals today have) but its very difficult to have a sample size large enough to really show this. The evidence here is interesting but doesn't seem very conclusive.
It’s definitely controversial.
@@nutyyyy Indeed, all these monospecific dinosaur genera seem unlikely from an evolutionary standpoint.
Great explanation. It's still so strange that fewer specimens are used to describe new species...
Like a catch-22, if you have a lot of samples you can see the variability, but if you have very few samples or only one then it's a new species because there's no variability to fit it within.
T-Rex is held to a higher standard than other species. This is because we have a lot of good skeletons, because we have done a lot of research, and because the dinosaur has a lot of fans.
First time I ever heard the name "Tyrannosaurus Imperator" was when it was being discussed as a possible name for a T-Rex specimen discovered by Dr. Keith Rigby. The reason they were opting for the name "Imperator" was because this T-Rex was supposedly the biggest T-Rex ever discovered and was rumored to measure somewhere around SIXTY-FIVE feet long!
A rex 65 feet long sounds ridiculous. Is there any proof of this monster rex?
@@symphonyofshred I said "supposedly". It turned out this Rex was more like 48-50 feet. I believe it's the one that was named "Peck's Rex" (that Rex might also be the one called "Scotty", I can't remember).
Titanosaurus and brontosaurus
65 feet long seems too big
Scotty is 43 feet long, slightly bigger than average, UCMP 137538 is 15.5-16 meters long, and MOR 1126 is rougly 14-15 meters long, so either you're talking about a Rex I haven't heard of, or you're likely talkin about UCMP 137538 or MOR 1126
I'm happy that you acknowledged that T-Rex had lips and u did that for the thumbnail
Regardless of the validity of the findings, I really like the names they picked out and hope they can be used if/when knew species ARE discovered.
Very interesting video. Thank You very much Mr. Thomas!
I think the possibility remains, though we'll still need more definitive evidence. Consider modern avian dinosaurs, there are many genera that each contains multiple similar yet distinct species, with the primary non-DNA methods to distinguish them being differences in plumage coloration and/or slight body size differences. Some examples are Corvus, Passer, Aquila, and Haliaeetus, to name a few. Either way, this is a really interesting paper and it's definitely fun to imagine that even with just the dinosaur genera we have discovered so far, they may still represent more diversity than previously thought! Tyrannosaurus species with different skin colors and plumages (if present)!
This makes me think of all the variations of jay birds and how they only slightly vary from one another( like minor changes to the size and shape of the beak to different shapes and colors to plumage). They are all considered to be jay birds but are considered different species of jay birds because of those minor changes.
4:17 Fun fact about this picture: This is Black Beauty, displayed at the Royal Tyrell Museum in Drumheller, Alberta, just four hours drive east of me. The curators had this posed the way it was found, but to do that they had to use a fake skull made out of cast because the T-rex's skull was far too heavy. The actual skull is on display too and is near the feet of the skeleton. It's so weird for me to see many of the photos you use come from a place so close to me (and my heart). Anyone who hasn't visited Drumheller is missing out!
Given what we know now about how quickly species can evolve compared to what we used to think 100 years ago, I think it’s unreasonable to think that T. Rex did not evolve significantly over the span of a couple million years.
On the other hand, scientific proof, as you pointed out, is very hard to come by. I think that this paper opens up new vistas for discussion, though.
Thanks for covering this issue. Another thing to note is that, even if these three species were valid, they likely wouldn’t be given brand new names. Plenty of older, now obsolete names were given to various rex specimens upon their discovery, and these would take priority. It’s possible the author just wanted to quickly get to name two new tyrannosaurus species before anyone else.
Yep, like _gigas_ and _imperiosus._
What is hilarious is that one of the main author’s previous names likely takes precedence over T. regina = Paul seems to have forgotten that he named one of the regina specimens as the holotype of Albertosaurus megagracilis in 1988 so T. megagracilis should have priority.
@@Ozraptor4 😂
I hate to do this to you Ben but I have to tell you that the definition you gave for species (at about 1:10?) is highly debatable even amongst biologists these days. A good example of why that definition doesn't really work that well is that grizzlies and polar bears have started interbreeding relatively frequently in the wild over the past couple of decades. I can't remember how fertile their offspring are however.
It would seem to me that the term "breed" may need to slightly redefined for use as scientific vernacular. It's not a very pleasant word, but I think it's the best description for the extinct "species" of humans that our ancestors intermingled with as well.
He did say we have a "fairly good" idea of what defines a species, which we do. Not perfect, and could stand refining, but good enough that it usually works.
Another one that comes to mind is the grey wolf, eastern wolf, red wolf, coyote complex(and toss in domestic dogs for good measure). Those animals can all interbreed with completely fertile offspring the result. By the base definition of species...that would make all of those animals the same species, perhaps "races" of a single species. Indeed there is a wide belief that red wolves and perhaps eastern/timber wolves are the result of coyote/grey wolf hybridization, and there is also strong indicators of a "mystery" canid in the mix that also was/is completely cross fertile.
@@NightwingGR1 you can add to that list the dingo, sometimes _Canis dingo_ sometimes _Canis familiaris dingo_ sometimes _Canis lupus dingo._
Another possibility, especially with the point made near the end about Tyrannosaurs' robustness possibly being more of a spectrum and less polarised as initially thought, is a ring species. Something where defining the borders of "species" would be difficult even if we could look back and have full knowledge of what they were like at the time.
Really clear and fair discussion of a controversial new paper. Thank you. I agree with your take take on this.
I think it is a definite possibility. Definitely needs more evidence.
Wow. What a fantastic video. I love how you break down both sides and counter arguments for each.
I know Regina means queen in Latin but I like that it is also the name of Dino Crisis main character, it's kind of ironic since she gets attacked by a T. Rex lol.
this was really well put together, thank you for shedding light on all the details. I am looking forward to seeing where this study goes too
There's also the possibility that there could have been two or three distinct populations that occasionally hybridized, but perhaps they were more subspecies than distinct species.
I think you nailed it when you said that they did it for media attention :)
Well, after watching all of this, with the new names: Imperator and Regina added to Tyrannosaurus, this amount of evidence is still very new, as for over a century, we been so used to the name Rex, but as long as they're all Tyrannosaurus, I don't appear to mind, though I always be a life long fan of the dinosaur for years to come.
I appreciate that you include the contention to these claims
Pretty well every paleontologist asked has said although it's perfectly possible, there's just not enough evidence at the moment. I think the video here nailed it; it was done more for publicity than anything else. Greg Paul has form at this kind of thing
"In biology we have a pretty good idea of what constitutes a species"
Oh, my sweet summer child.
In an article I read about this, it stated that the authors of the paper, said that it is possible that these differences may only be individual variation or sexual dimorphism, which makes sense this is only a proposal, a theory if you will which even the authors question themselves.
Ah yes. I've always wondered why sometimes the t Rex had a cool looking skull, and other times it had a fucking cool looking skull.
Given that Orcas have different species that only differ in habitat, diet and behaviour it could be very likely that the Tyrannosaurs did behave differently and had some corresponding physical differences. I think it would make sense but I doubt we'll ever get a accurate answer :(
Kind of like how there are 4 current species of giraffe. How important is the distinction really about extinct animals between very closely related species and subspecies
Are they separate species or subspecies?
@@SoulDelSol The 4 recently recognised species of giraffe have vastly more pronounced skeletal differences between each other vs the flimsy characters that Paul is proposing for his 3 separate Tyrannosaurus spp. For example Lee. et al 2022 demonstrate substantial differences in the foot bones (fibula, calcaneus, and astragalus) between Giraffa camelopardalis and Giraffa reticulata.
@@nutyyyy if you're talking to me there are 4 species of giraffes confirmed through dna plus multiple additional subspecies. Even with these living animals there has been confusion and disagreement with this up until dna was done. As for orcas I'm not sure but i wouldn't be surprised if there were both.
@@Ozraptor4 oh i agree, this proposed paper seems flawed. Like he just wanted to name them himself or something. There is very little distinction between proposed t rex spin offs and seems like it's just one researchers attempt to make a name for himself rather than supported by actual robust evidence
If anything, this paper reveals the obsession that humans have for naming things more than anything else.
"T Regina" ........ even Paleontologist want a new Dino Crisis
I LOVE y'all's depth of coverage of all the paleontology news. I've been a subscriber for at least 2 years and it's just continually and increasingly impressive.
The 'robust vs.gracile' argument doesn't convince me to be honest. Compare the femurs of an average rugby player with an average football (soccer) player and I guarantee you would see enough of a difference in thickness to genuinely believe they are 2 distinct species if you didn't already know they were just the femurs of 2 humans.
A better modern example would be the okavongo delta lions which are absolutely enormous, just because they live alongside a lot of buffalo.
Very interesting ideas brought forward though, great video all in all.
VEry facinating, great explaining!
It would be interesting that what's happening is how a bobcat and the Canadian lynx are almost indistinguishable. They're all lynxes but are significantly different enough to be their own species.
There are probably many species that can not be distinguished from each other with only fossil remains. But the larger the species, the smaller the probability.
Subspecies then?
@@MithriVideolari Maybe.
I think the only true way to prove anything about fossils is to actually see the living creature. A sample, a corpse or as it is now, a fossil, can only reveal so much. Even today species that are alive are getting put into their own subspecies or an entirely different genus due to how they behave, or whatever, making the creature distinct enough to those like it.
Thanks for illuminating the discussion in a fair and balanced way. I'm curious where the follow up studies will lead.
Meanwhile everyone does say it could be dubious the fact that speciation happens all the time as well as the conditions of N America was perfect for Speciation to occur in mid to late cretaceous! Like Grizzly Black and Polar bears for example!
Also The Torosaurus is definitely a different ceratopsian now where a recent study indicate or validated their young subadult fossils discovery
@Leo the Anglo-Filipino Indeed alas until a very few years ago all central slender snouted crocodiles deemed the same species now its totally the opposite same for the primates
It's possible that some of what we currently consider to be T. rex may represent different species, the problem is that the authors did a very poor job presenting their case, which is what really matters in this case.
Look up Jack horner and allometric cranial ontogeny.
@@thedoruk6324 Philosophy of science 101, Occams Razor: Entities are not to be multiplied without necessity.
@@juanyusee8197 That part is true they kinda jumped up to opportunity to rename names
People just learn things everyday what a video great thoughts facts ideas good vid man
Of course it’s highly possible that Tyrannosaurus includes more species than just rex, but the criteria provided in this paper are just not it for me and many others.
I've always been drawn to the idea of allometric cranial ontogeny, it makes so much sense.
These creatures existed for hundreds of millions of years and then disappeared the truth is they developed and created space travel and are still among us today the history channel doesn't lie
Har har
Very interesting. Tyrannosaurus is my favorite dinosaur!
personally, i feel as though there are multiple species of tyrannous that we haven't discovered yet, however the paper here doesn't use enough predominant differences to truly be able to classify them as different species, rather individual variation or genetic malfunctions, considering the fact that most of the differences here are too minor to really leave impact, the femur sizes can easily be because of age or individual variation, most of the claims in this paper rely heavily on pedantry and incredibly minor details that aren' very meaningful
Would be great to see this study tackled once more once specimens have been discovered
Judging by the bones alone a chihuahua, a pitbull and a golden retriever are separate species. Male and female elephant seals will also be considered separate species based on the bones alone. So... Before jumping to conclusions I believe we will need more and more reliable data.
Great video, Ben. Just to correct one thing you said - even in contemporary biology, the species definition issue is not simple at all, and there are lots of grey areas where some of the more common definitions don’t align with actual defined real world species. And that’s the benefit of DNA analysis and real world specimins to deal with!
We've got the same problem in Paleoanthropology with the H. bodoensis proposal. Lots of debate as to if it should be labeled a new species or not. I think it has been recognized since the paper was first published late last year, but many of us still don't necessarily think it should be classed as a new species.
What the hell am I looking at in your profile picture 🤣
@@winter2716 isn't it obvious? It's a broom leaning up against a wall! You have a dirty mind ;)
@@bdeclerc Oh, I see it now! Their username certainly doesn’t help.
@@winter2716 pretty sure it's on purpose ;)
@@bdeclerc Of course
T. Regina to Jack Horner:
"Stop trying to make scavenging happen! It is never going to happen".
Couldn't this just be regional variations on the same species? The same species of an animal after all tend to vary dependent on the kind of area or location in the world and often develop certain unique traits but are still the same one.
The name Tyrannosaurus Imperator sounds all kinds of badass
To show how shoddy the paper is = In 1988 GSPaul named Albertosaurus megagracilis with the holotype LACM 28345 (now almost universally considered a sub-adult T. rex). Now in 2022, he erects Tyrannosaurus regina and assigns this specimen to it, with no mention of his previous nomenclature. If LACM 28345 is diagnostic enough to be assigned to T. regina, then T. regina is a subjective junior synonym of Paul's own T. megagracilis.
Scientific self-own in its finest.
I hope there are multiple species for Tyrannosaurus Rex, just because Tyrannosaurus Imperator sounds so cool
Really not convinced by the paper at all
Why
The hypothesis and concept behind it are actually good, but the methodology and data presented in it was abysmally bad.
@@josephrobertson8660 Philosophy of science 101, Occams Razor: Entities are not to be multiplied without necessity.
Great summary of this topic. Very fair and true to the facts.
It got me thinking of something which I didn't read or hear pointed out elsewhere: Maybe the greater variation in femur proportions can be explained by the size of T. rex? This species could grow a couple of times heavier than the other tyrannosaurs and Allosaurus. The variation in absolute mass ought to be bigger than in these taxa. Sure, a smaller species may be more heterogeneous, but this can be checked in a principal component analysis of some sort
We stan our Tyrannosaurus regina Queen. 🙏🏻
Slay tyrannosaurus regina queen 💅
Tyranno Imperator is a name I never thought I actually wanted
As far as I'm thinking, if three potential triceratops species. More or less stratigraphically separated, may have existed, according to the law of co-evolution. At least to me it doesn't appear that strange that a similar pattern may have been case for the tyrannosaurus-genus. Especially when taking into account the prey and predator-relationship between the two.
The degree of co-evolution which occured between tyrannosaurs and ceratopsids never ceases to amaze me. While it is inaccurate to attribute intent to the evolutionary process, it honestly comes across almost like an arms race between jaws and horns, teeth and frills. While it is likewise inaccurate to apply some terms to animal taxa, if there were any two groups of animal which deserved to be called rivals, it was the tyrannosaurs and ceratopsians. It is perhaps fitting that the (non-avian) Dinosaurs weht extinct when both "factions" reached their zenith. Regardless of such baseless, indulgent romantics, I do think you have a good point. It seems at least a fair consideration to use the two (three?) species of Triceratops as analogy to possible speciation of Tyrannosaurus, based on the established co-evolution between their taxonomic groups.
Good jobs whoever naming the species now youre making me wanna play Dino Crisis again 😭
Would those variations point more towards subspecies rather than speciation? Like, subspecies are the same species, just different enough in some way to be distinct. Like, look at yellow belly sliders and red ear sliders. Same species but ybs are a subspecies with a unique phenotype
i like how you showed different pictures of Acrocanthosaurus in the beginning of this video, very realistic
for the time being lets keep it at T-Rex.
THough if it eventually need to be split, I don't think those are bad suggestions for names at all.
The nightmare comment reminded me that while I have never had a nightmare about Tyrannosaurus, I have had one where a pair of Deltadromeus systematically took apart my house wall by wall, trying to get to me. I might be the only person to have one about that taxon, lol.
Imperator is such a good name for another tyrant. But regina is a little silly.
Just because I know a couple Karen-like women named Regina lmao
One of the specimens assigned to T. regina happens to be the "Dinotyrannus megagracilis" holotype, so even if the authors are correct in their assessment, the taxonomically correct name for this proposed taxon should be "Tyrannosaurus megagracilis".
@Leo the Anglo-Filipino Regina George from Mean Girls as a dinosaur…
Good Lord why is that the first thing I thought of as soon as I read that? 🤣
Regina translates to queen in Latin so I think it's a pretty good name. T.rex and T.regina, the king and queen of the dinosaurs.
Regina is the name of the protagonist in the game "dino crisis" so interesting coincidence there
I like the T.Regina name, especially since it makes me think of Regina, protagonist of Dino Crisis, which I find funny.
Let's name Dinosaurus Species after Video Game Characters.
I love how we could potentially have this line up of one of the most iconic intimidating animals in media/history
Rex - 🦖🦖🦖🦖
Imperator - 🦖🦖🦖🦖
Regina - 🦖🦖💅💅🦖🦖
I have the Princeton Field Guide to Dinosaurs by Paul from 2016 and there are two potential species of Tyrannosaurus mentioned: an unnamed robust species and T. rex. So it’s interesting that this idea made it into a paper now.
Also get ready for the "everything belongs to Centrosaurus" paper :D
I'd say the evidence is still far from compelling, but worth further research. I hear Horner is planning a paper on how T. Rex is a species of ceratopsid.
Made me chuckle!
Fantastic channel!
So we have T-Rex, T-Reg, and T-Imp?
Not really for now at least, the data and methodology behind this poor was inadequate and pretty bad.
No
I love the lumper vs splitter argument
Imperator is a pretty epic name well done to whoever thought of that.
Philosophy of science 101, Occams Razor: Entities are not to be multiplied without necessity.
That's such a cool name, "Emperor of the Terrible Lizards" hot damn!
Check Paul's resumee (one of the authors of the paper), he loves naming new species for the sake of it, based on limited or unconvincing evidence. Several of his proposed species are considered invalid or dubious. He seems like an attention seeker who just wants to be talked about.
This. I don't mind the proposal of more than one Tyrannosaurus species if it were well sustained with evidence, but the author's reputation and indeed the frail evidence presented makes me think the lad just wants to stir things up for the sake of it. I mean, just look at the grandiose names he came up with FFS!
The whole thing feels very "History Channel-y" to me: "I'm not saying a̶l̶i̶e̶n̶s̶ several Tyrannos but yeah a̶l̶i̶e̶n̶s̶ several Tyrannos"
I absolutely love the names they chose for the supposed new species.
I feel this is a great example of how the 'species' model of classifying life forms doesn't make much sense. Nature is not logical and has no obligation to conform to our own logical frameworks. When it comes to 'species' - they are not fixed, easily defined things and they never were. Life forms are unfixed, changing, dynamic, open systems weaving through time, their morphology and genes morphing and shifting with the environment. Life acts more like a fluid flowing downhill than it does a discreet collection of easily definable categories. It is our own tendency to obsessively categorize and fragment the world into an ever increasing number of bits and pieces which is the issue.
This is a very intriguing proposal, but I'd rather wait and hear for more evidence on it. At this point, I wouldn't be surprised if this ended up being true, considering how much paleontology has changed/expanded over the years.
I thought they were found to be just juveniles, not separate species. Curiouser and curiouser.
I believe that that was a seperate argument
Very interesting 👑
I hope they'll stay with T-rex... Just because T-rex is the poster boy of paleontology, it helps with vulgarisation because everyone seems to have a crush on it. Just like we didn't decide to call it Massospondylus giga, even if we're supposed to, it would be better in terms of "marketting" for paleontology to have only T-rex.
So uh
Sorry to be that guy but
It’s “T. rex”, not “T. Rex”, or “T-rex.”
Superb! Very thorough and thoughtful presentation of what science should be: continually questioning and not settling on premature proclamations. Even if there is only one species of T. rex, it is far better to analyze the minutiae of the limited evidence than to make bold assumptions. What happened to Doug? Did he suffer the fate of those poor souls at 11:48 and lost his mind? Get well soon, Doug!
Can T.Regina and T.Rex be just *subspecies*? Maybe there’s just Tyrannosaurus Rex, that descended from T.Imperator and one subspecies that is Rex Regina and another that is Rex Rex; just like it happens with tigers, if we apply these same techniques to separate species we could get almost about 8 new species of Panthera, that are actually different subspecies of P.Tigris.
I don't think that they can consider them sub-species, because we can't see their living differences, if I had to guess, however, you're absolutely right that that could be the case
Forgot to specify sub-species are determined by DNA aswell, typically, however your idea definitely can still be plausible
Nice analysis. I can't help thinking about dogs here. A greyhound and a mastiff are both still Canis familiaris.
I personally don't agree with the paper. The hypothesis is interesting, but the evidence is sparse.
11:46 I do agree with this however.
From what I got from this video, it sounds like the more significant point is that the dentition changed from older to newer specimens, & the genus developed the robust & gracile forms later as well. It sounds to me like the researchers were overly concerned about the data they had about the robustness & rex vs regina.
I have to disagree with naming two different species...that's really not taking into account the variability between individuals. It's even jumping over subspecies and going straight into two different species. I think this was way too early of a jump to even come close to with such a small number of specimens. The variation could very well be just based on different sexes.
I don't care if T Rex has feathers, but I don't want him to have lips. I want my T. Rex to be as scary as possible!!
The dinosaurs can only have one king 👑, Tyrannosaurus Rex!
I don’t mind 3 tyrannosaurus species but at least give the good names.
I suppose they are staying within the rex theme. Rex is King in Latin, Imperator is Emperor and Regina is Queen.
For real these names make it sound like the guy was trying to create a yugioh archetype.
@@notaverypopularchannel4878 I mean, I wouldn't say no to more dino support.
Tyrannosaurus Imperator is one of the most badass dinosaur names I’ve ever heard