Paleognaths and the Rise of the Ostriches
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- Опубликовано: 18 ноя 2023
- Originating during the Late Cretaceous as terrestrial foraging birds, albeit with strong flight capabilities, the Paleognaths thrived in the aftermath of the K-PG Extinction Event. From their origins in the northern hemisphere, these animals spread into the southern continents and independently evolved both flightless habits and large sizes on several occasions.
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I always had a feeling ostriches and rheas were more basal than emus, cassowaries, kiwi, moas, and elephant birds through virtue of them having wings that serve some kind of purpose. I have no clue what emu or cassowary wings look like while kiwis, moas, and elephant birds just don't have arms at all.
Turns ok genetic testing has proven you right!
Emus have very strange clawed wings.
Technically, the only birds known to lack wings were my favorite, moa.
@@Nigel_BCwith no muscles attached, they can't move them
Kiwis do indeed have wings, they have a single claw at the end of them. Moas were the only modern representatives that had no wings.
It's odd that ostriches, emus, cassowaries and rheas all have bare necks but moa and elephant birds are always depicted with feathered necks.
I don't remember which moa it was, but there was a mummified head and neck which was mostly bald
I'm betting the reason why the large paleognaths that evolved on islands were vulnerable to predators is because they were pressured to have reduced reproductive capabilities. The ones that evolved on the main continents would probably need to lay a lot more eggs because some of those chicks would get eaten, while if they did the same on an island, they would overpopulate really quickly.
imo a very awkward formulation "were pressured to have reduced reproductive capabilities" ... and it is ultimately is wrong. Why? Because they (as you write yourself) "evolved on islands" . They arrived there small, therefore there was little to no pressure from ressource/niche availability to have fewer offspring! This is a trait they evolved like any other large animal as they grew.
One reason for large animals to be vulnerable on islands is simply that islands are isolated and somewhat small. Therefore the maximal carrying capacity for their population will be small as well. Small populations are always vulnerable -> i.e. to disease, because the whole population might get infected and the genepool is to small for a significant probability of there being resistant individuals. From bad weather like storms, droughts/famine to predators and mutations if a single animal dies in a small population, a higher portion of the whole population dies than in a big population. If 5 of 10 die, and only one sex survives, the population is doomed, "functionally extinct".
Island being small also means there is likely only one population, meaning that if it dies out (for any reason) it can not be repopulated from another population (metapopulation theories).
Were are you going to run to away from predators on a small island? You can´t, so predators are gonna multiply and eat everything they can find until their prey has been eradicated. Then they going to die out themselves also. If the area is large enough the effort off hunting the last ones down gets so high and it gets unlikely that predator and prey meet at all, that at least a few will survive.
..and lastly (with many known sad examples) and a evolutionary causality that should here not be underestimated is lazyness/dumbness. Running away/fleeing costs a lot of energy and no animal does when it is not necessary. Animal will not be shy if they know they don´t have to fear for their lives. On the other hand this means if they don´t know that something is a threat, they won´t react either. New unknown predators could oberwhelm a small population before they learn to avoid them.
I absolutely love the recent Elephant bird popularity surge 😍
Since birds' reclassification as dinosauria it's seemed to me that The Age of Dinosaurs also needs to have its boundaries updated up to when the giant predator birds lost their dominance to the new mammal predators, rather than at the end of The Cretaceous. Unfortunately some old habits die hard.
Well it's not like phorusrhacids were around in the Cretaceous and survived the KPG extinction. The age of dinosaurs (as in being the dominant land animals) DID end with the Mesozoic. Phorusrhacids may have retaken the role, but it was still a new age, not a continuation.
No, just no. For starters predatory birds were not the single large predators in the environments they existed, second they have varying rates of extinction (bathornithids in the Miocene, terror birds in the Pleistocene, raptors still in modern times) - none of which caused by mammalian predators, btw - third that's not how geological areas are mapped.
That is a fair point, but what about the end Jurassic and the end Triassic extinctions? Dominant dinosaur genera didn't survive those events, while less dominant ones did and they moved into dominant roles. Birds survived The K-Pg Extinction and must have been outperforming other groups in that vaccum in order to regain dominance, which they then lost over time as mammals grew more dominant. Heh, it's a bit like talking about Byzantium when discussing it like this. 😆 @@yissibiiyte
Not being the only dominant predators is a fair point, but the other two points you raise are not as relevant. I said they lost dominance to mammals, but I didn't say they lost dominance because of mammals, as the eras are mapped out now dinosaurs didn't lose dominance because of mammals but because of heavy volcanism and a catastrophic impact. The point about the transition being a slow dissolve rather than a hard cut only makes that boundary harder to define. We still call lions "The King of The Beasts" despite their range being reduced to a sliver of what it was. Granted, that isn't a scientific definition of a lion, but just to make a comparison between widely accepted perceptions. The K-pg Extinction killed off more than just the non-avian dinosaurs, but they are the ones who get all of the attention. There was a lot of backlash against the idea that birds are members of dinosauria because it changed the way we define previously accepted biologic history; as such it has seemed to me it suggests re-examining accepted geologic history to accommodate our better understanding of what occurred. Perhaps a kind of Dinosaur Dark Ages in the immediate aftermath of the extinction event. @@carlosalbuquerque22
@@WaterShowsProd while the dominant genera did die out at the end of the first 2 periods in the Mesozoic, their immediate "successors" were still fellow dinosaurs, with no gap where a non-dinosaur was dominant.
As far as I'm aware, phorusrhacids were not the first large land animals to emerge at the end of the KPG. Mammals such as brontotheres had already attained large sizes before phorusrhacids appeared, so this was the first time dinosaurs lost their unbroken chain of dominance, even if only temporarily.
But I get your point, maybe I am too brainwashed into thinking of the KPG as the be-all and end-all of dinosaur dominance.
Thank you very much for this! BTW with regard to all those particular skill requirements coming along with flight, I assume, their well flying ancestors might have had proportionally bigger brains.
Hey Dr.Polaris, right after the evolution and the history of the Notungulates, why don’t you also get to make a suggestion to create the RUclips Videos Shows about the evolution and the history of the Extinct Prehistoric Giant Predatory Sea Birds called the Pelagornithidae in the next couple of weeks to think about that one coming up next?!⭐️⭐️⭐️⭐️⭐️👍👍👍👍👍
You actively help me learn more about all those cenozoic animals, especially their lignage. Thanks a lot
A bit late, but just wanted to say that this was a nice video. I had no idea that the evolution of the ratites was this complex. Nice video.
However, I did have a question. I've been on your channel since the days of Alter-Earth (more specifically, when I was recommended your video on Middle Oligocene North America in Alter-Earth.) But I couldn't notice that despite the updates on Deviantart, there haven't been videos on it since the most recent on on Miocene Africa. Will there be any videos continuing the series in the future, or has it been canceled due to a combination of outside factors? (Then again, if that is the case, then it's understandable, especially since a lot of paleo-discoveries have occurred since the series began that may have changed the environments and how they change in the Cenozoic, thus making the "initial groundwork" (the way the end of the Cretaceous was and the way the earlier Mesozoic was when the series began) outdated.)
I literally just finished watching Clint's Reptiles' video on Paleognaths (made some months ago). And now you post a new video about them? Did RUclips sense you were uploading yours and thus suggested me the other vid to anticipate my interest on the topic?
great video and can't wait for the one about the Notoungulates.
Superb effort. 10 stars, you are eclipsing the great Naish.
So happy that this topic was covered! Not sure if my recommendation from a few videos ago inspired it, but I’m still very happy with it nonetheless! I love birds and ostriches and their relatives are among the most interesting. I’m glad that their history got covered, as well a brief lesson on Pachystruthio. It’s such an interesting prehistoric animal that needs more attention.
Ironically, I often learn about contemporary animals on this channel. I had no idea about the Tinamou in South America, let alone that Kiwis ARE actually related to Ostriches...that always seemed like a bias trap to assume it and yet here we are.
Notoungulates next episode? I hope it will be a really long one. Can't wait.
Incredible video today as well
Thanks so much for your videos!
I remember reading Gould's account of Kiwi evolution. That has all changed but thanks for clearing up this group for me.
Great video. And THANK YOU! I've been waiting for a good video on the notoungulates.
An excellent presentation that I've been waiting for someone to do for a long time.
Oh man had no idea that there was a group of flightless birds native to asia
Man, I’ve been hoping I’d see a Video on ANY, type of Extant Flightless bird On ANYTHING, now currently I’m on the 12 minute mark but I’m hoping the next video is on Turkeys, you know, Thanksgiving and all, anyways I gotta say my Personal Favorite Video regarding an Extant Family of Animals you’ve covered. I just finished it, NautoUngulates, Cool, Cool, I’ll watch it of course.
I need to get some Toxodontid art online before your next vid for a chance for it to be featured
Now do evolution of hedgehogs, moles, anteaters and lesser carnivores like civets, mongooses and fossa
nice video
Strong presentation! A few corrections based on trait analysis: 1. Madagascar elephant birds (Aepyornis maximus) are more closely related to African ostriches (Struthio). Tinamou-sized, four-toed and flightless Early Cretaceous Patagopteryx (not mentioned in the video) from Patagonia is basal to both. 2. New Zealand moas (Aepyornis) are more closely related to South American hoatzins (Opisthocomus, not mentioned in the video). 3. Kiwis (Apteryx) are more closely related to extant woodcock (Scolopax) and snipe (Gallinago, not mentioned in the video). Eocene Pseudocrypturus, a lithornithid from North America, and Late Cretaceous Vegavis, from Antarctica, are primitive members of this world-wide clade. 4. Rheas, emus and cassowaries are giant tinamous, not as closely related to the other giant birds. 5. Genomic tests work wonders when fresh, but deliver untenable results in deep time studies that nest bats with rhinos and cats. 6. Clades should not be defined by a dozen traits, which can and do converge, but by the last common ancestor method after a wide gamut analysis of several hundred traits and taxa. 7. Be careful with your upcoming ‘notungulates’. Some traditional members are marsupials, while others are placentals. More details and cladograms at ReptileEvolution online.
Very interesting comment about the perceived insular gigantism on this family of birds. Definately, ancient giant relatives in northern hemisphere cast doubts on this notion.
Very nice synopsis. Never really thought about the lineage of the Ostrich but you made it very interesting.
But could you please tell me were the "Chiner Region" is, I'd like to get there.
I was told part of the reason kiwis laid massive eggs, Is do to it being descendant from large birds do to it's relatives. So them not being Island Dwarfs is interesting.
I'm a little curious Is there other small birds that lay massive eggs for there size?. it would be weird if the only small bird that lays massive eggs having large relatives being a coincidence.
The most common Kiwi's the brown Kiwi -A kiwi chick at 6 weeks old is chased out by Dad who does the rearing ,females protect territory as Kiwi can pair bond for life .Makes great sense to be born fully formed ,more fully formed the better to survive. It was a great shock when it was discovered Kiwi most closet relative was the elephant bird and then they had gotten bigger since the Miocene .when they became Nocturnal isn't known .Kiwi can produce eggs at 3yrs old .
What’s your background music
Ooh, another sanu episode...
Yay! Notoungulates! (Thanks for Paleognaths!)
I love this giants birds
Seeing these birds in real life will definitely convince you that birds are dinosaurs if you aren't already convinced. I believe Paleognaths share closer relation to Oviraptorosaurids than to Neognaths. Neognaths appear to have similar traits to those of Dromaeosaurids while Paleognaths have a strikingly similar body plan to Caydipteryx, with the only difference being the pelvic structure. Which is not unusual for theropod dinosaurs to evolve "bird" hips several different times in different clades.
You do realise all avians are more closely related to each other than to other dinosaurs? They're a monophyletic group.
@@yissibiiyte morphology dates the common ancestry of all avians to the mid-Jurassic. Around the time Maniraptorians appeared in the fossil record. Either birds evolved from at least two to three different clades within Maniraptoria or all Maniraptorians are avians.
@@logenvestfold4143 why do you say birds evolved from multiple different maniraptorans? They all descend from the single maniraptoran clade avialae. As I said, they are monophyletic, they aren't a bunch of different maniraptoran lineages.
@@yissibiiyte I’m saying the current taxonomic grouping is a bit backwards.
Imagine the amount of grease fires that would be caused by trying to deep fry one of the ancient Struthios in a turkey fryer. Also gonna need a bigger fryer. Much bigger.
I once say an ostrich attack a zebra at a zoo not far from me and a chick was present at the time. These birds are not to be underestimated and I certainly wouldn't anger one.
wierd... I read quite a few papers about weight estimation from bones on non avian theropods and birds a few years back. i.e. Aepyornis/Vorombe and moas... but I can´t remember reading anything about Pachystruthio reaching weights of up to 450kg...
Land Birds for the win!
When will cryptids return to this channel?
Paleognaths above all
board!!!!!!!
Ostriches are cool.
Are these birds related to Phorusrhacids of South America
In that they are Birds, yes, closely related no. These Birds (Struthionimorphae and Notopalaeognathae) are of the Infraclass Palaeognathae. Phorusrhacids was of the Infraclass Neognathae.
Arabian ostrich went extinct in 1966, officially probably earlyier in 1920-30's
also there escaped population's of ostrichs in australia.
Rise of the Ostrich's History
In other words...there were ostriches all over the place at one time!
If the Kiwi didn't evolve from a giant ancestor how do we explain the size of it's eggs?
He said the Kiwi developed it's small size from more massive ancestors. As in it's ancestors was bigger then over time the Kiwis size reduced.
7:37 You know half of Africa is in the Northern Hemisphere right?.
Are "terror birds" more ancient?
Different bird group .The Paleognaths lack a breast bone /Keel for flight muscles .The one today that can fly from South America ,is odd since it has no breast Bone/keel but can fly . Also why holding a Kiwi is not the same as any other birds .The others alive today are to big of course to pick up and hold .😅
No Terror birds was of the Infraclass Neognathae in the Order Cariamiformes, that also includes their closest living relatives the South American Seriemas. The order Cariamiformes is most related to the order Falconiformes (Falcons and Caracaras), followed by the Order Psittaciformes (Parrot-forms) and the Order Passeriformes (Songbird-forms).
I wonder what these large relatives of ostriches tasted like seeing as I find ostrich meat very delicious 😋
As the wise man once said :
It tasted like chicken