The Most Ridiculous Notion Yet

[suspsy]

As many of you know, David Peters is a genuinely talented artist who wrote some great children's books back in the late 80s and early 90s, complete with foldout pages. Since then, however, he has steadily degenerated into a bona fide crackpot with delusions of scientific grandeur. His websites, ReptileEvolution and Pterosaur Heresies, are so full of demonstrable falsehoods and nonsense, it would give anyone an excruciating headache to list even a quarter of them. For your own sake, don't ever use them as references. And this may well be his barmiest argument yet. He claims that Homotherium is not a machairodont or even a felid at all. Instead, he insists that it is a canid.

That's right, a sabre-toothed dog.

https://pterosaurheresies.wordpress.com/2023/05/20/sabertooth-homotherium-is-a-canid-not-a-cat/?mibextid=Zxz2cZ&fbclid=IwAR0l54V3HdwCzXegIpSDxY-97s2VUfRgULDpnFUgCtFL6EREs2OZNNlRBI4_aem_th_AaZzek5G-8MPXGmBVSH-C-fER6jWell6IUwwJGXr5mSUYWS76ka2wS5uo6Z3MZRU37c

[Dusty Wren]

I'm possibly even more offended that he's also decided the aardwolf is a canid for some reason.

[EmperorDinobot]

This is more of a "what-if" scenario than anything else.


Kinda like The DaVinci Code.

[stargatedalek]

It's truly a shame that so few others tackle the range of animals he does, he has something of a monopoly on early Triassic reptiles.

[suspsy]

It's truly a shame that so few others tackle the range of animals he does, he has something of a monopoly on early Triassic reptiles.

It's also truly a shame that a Google image search for skeletal drawings of non-dinosaurian genera often result in his horrible website.

[Remko]

I'm possibly even more offended that he's also decided the aardwolf is a canid for some reason.

Most people think hyena's are canids...
And look at you in bewildered amazement when you explain that they are actually more related to the feline family.

But from someone who pretends to be a scientist, you would expect better.

[stargatedalek]

It's truly a shame that so few others tackle the range of animals he does, he has something of a monopoly on early Triassic reptiles.

It's also truly a shame that a Google image search for skeletal drawings of non-dinosaurian genera often result in his horrible website.

Personally what bothers me the most is when he gets things right. There is so much pushback against him at this point that when he's the first to do something, everyone automatically assumes it's baseless. I fear Longisquama will forever just be reconstructed as a lizard like animal with giant back crests, instead of the strangely proportioned, possibly facultatively bipedal, reality.

[ceratopsian]

I'm afraid that I for one have only ever seen Longisquama reconstructed with giant back crests - can you point me in the right direction for the facultative biped please, @stargatedalek?

[Remko]

I'm afraid that I for one have only ever seen Longisquama reconstructed with giant back crests - can you point me in the right direction for the facultative biped please, @stargatedalek?

Here you go:

https://www.reptileevolution.com/longisquama.htm

[GojiraGuy1954]

I'm afraid that I for one have only ever seen Longisquama reconstructed with giant back crests - can you point me in the right direction for the facultative biped please, @stargatedalek?

Here you go:

https://www.reptileevolution.com/longisquama.htm

Do NOT pick that website

[stargatedalek]

I'm afraid that I for one have only ever seen Longisquama reconstructed with giant back crests - can you point me in the right direction for the facultative biped please, @stargatedalek?

The idea of it being a facultative biped comes from it being closely related to Sharovipteryx. Longisquama has a giant head and really long arms, almost monkey-like, with the back half unknown. But the extremely safe decision to base it's hind section on the closest relative is very rarely done, instead it's usually just given a lizards back half and it's long arms are either shrunk or hunched strangely to make it walk like one.

Compare the known material of each for yourself to the typical Longisquama reconstructions.

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There is even a really neat potentiality here that bookends Longisquama's story nicely, that it could reasonably have been a glider after-all, using those missing hind legs and not the back crests. It has a build of an arboreal animal, it could easily have simply been less specialized for it than Sharovipteryx hence the lack of reduced forearms.

[TaranUlas]

Don't forget the part where he thinks Smilodon is a Saber-Toothed Weasel. That was around the point where I just laid my head down on my desk and needed a minute. He also thinks that Borophagus is a member of a South American Carnivoran family?! And that Sarkastodon is a weasel.

So among the many many MANY issues with his studies, we need to explore his methods and why they are bad.

* His tool for analyzing skulls is atrocious and sees things that are not there. We know this because he tested it on a Chicken's skull and it turned up bad data. Chicken skulls are one of the most studied skulls of any animal in the world. If you are turning up completely unforeseen data like new pieces of bone on it, you should almost assuredly check your method because it is bad. Instead he thinks the issue is that everyone else doesn't get his results.

* His character analysis for his "Cladograms" is just awful. It is 230 or so characteristics... based on Pterosaurs. I cannot emphasize this enough, but that is not how you analyze anything except for pterosaurs. Character exclusion and inclusion is a far more important trait than Taxon inclusion or exclusion and David Peters is just... awful at it. He does not have anywhere near enough characters for his cladograms.

His methods are awful and this hypothesis is just bad. It is really really bad.

[Stegotyranno420]

He exists to taunt academia

[Bowhead Whale]

You are talking about one person in particular. I must admit I don't know him, but I did notice something: today's books for kids about dinosaurs are hardly ever good. What do they say? They talk about the ferocious looks of the Triceratops, the big teeth of T-Rex, the big "bigness" of Apatosaurus... in other words, just say dinosaurs look spectacular. Really, really dumb. When I was a child, I had dinosaur books that told a whole lot more. They were not always true (of course, paleaonthology did evolve), but they did talk about the periods, the aquatic animals, the prehistoric plants. I still read them with pleasure today. But today's dinosaur books for kids just make my brain melt. Just if like dinosaurs were just interesting because they were big and were ferocious-like. Boring. Terrible. Brain-melting.

[suspsy]

Not true. Well, it is definitely true that there are a lot of truly atrocious children's dinosaur books out there, but I've come across my share of genuinely good ones too. One simply has to be thorough in their search. I strongly recommend this title in particular:

https://www.amazon.ca/Kaleidoscope-Dinosaurs-Prehistoric-Life-explained/dp/0711266913

But what does that have to do with the topic of Peters and Homotherium anyway? He hasn't written any children's books in decades.

[BlueKrono]

My world was shattered when I "learned" that Andrewsarchus is a giant elephant shrew. Is that all bunk?
https://pterosaurheresies.wordpress.com/2016/12/19/fleshing-out-andrewsarchus-the-giant-tenrec/

[GojiraGuy1954]

My world was shattered when I "learned" that Andrewsarchus is a giant elephant shrew. Is that all bunk?
https://pterosaurheresies.wordpress.com/2016/12/19/fleshing-out-andrewsarchus-the-giant-tenrec/

Yes

[Bowhead Whale]

Not true. Well, it is definitely true that there are a lot of truly atrocious children's dinosaur books out there, but I've come across my share of genuinely good ones too. One simply has to be thorough in their search. I strongly recommend this title in particular:

https://www.amazon.ca/Kaleidoscope-Dinosaurs-Prehistoric-Life-explained/dp/0711266913

But what does that have to do with the topic of Peters and Homotherium anyway? He hasn't written any children's books in decades.

I sure would like to come across them (the good books you talked about).

[dinofelid]

But the extremely safe decision to base it's hind section on the closest relative is very rarely done

Are you saying it's a safe decision to reconstruct Longisquama as a glider with a membrane extending from its legs like Sharovipteryx, or are you saying it's most likely to have had long legs even in the absence of a membrane? If the latter, if we could look at the ancestors of bats or pterosaurs from some time shortly before any gliding or flying adaptations, I wouldn't expect their arms to be nearly as long proportionally as their flying descendants, though maybe it's plausible they'd be a little longer than other similar animals in the same niche since that might make them more likely to evolve in the direction of gliding/flying.

Also, the first skeletal reconstruction of Longisquama you posted was by an artist named Jaime Headden, in this post he had a new reconstruction which has the limbs less erect, he explains why he considers his older reconstruction less plausible:

Even at the time I placed this image on this blog, I'd decided that evidence didn't favor an erect, archosaur-style posture. My reasons at the time were based on some details of the shoulder and hand, but these are not entirely consistent only with erect postures or digitigrade limbs.

For one, the shoulder suggests a lateral orientation for the humerus, the forearm presents a bowed ulna consistent with flexed elbows, and while the metacarpals are long, the carpals are small and irregular, and I am reminds of the feet of frogs and other tetrapods in which the metapodial elements contribute to digit length. Meaning, the limbs would be possibly splayed and plantigrade. Be aware this is speculation, and details of the original specimen are sparse as the preservation is terrible aside from the impressions, with the granularity of the slab extremely rough, meaning some elements are less differentiated than grains in the matrix.

[stargatedalek]

But the extremely safe decision to base it's hind section on the closest relative is very rarely done

Are you saying it's a safe decision to reconstruct Longisquama as a glider with a membrane extending from its legs like Sharovipteryx, or are you saying it's most likely to have had long legs even in the absence of a membrane? If the latter, if we could look at the ancestors of bats or pterosaurs from some time shortly before any gliding or flying adaptations, I wouldn't expect their arms to be nearly as long proportionally as their flying descendants, though maybe it's plausible they'd be a little longer than other similar animals in the same niche since that might make them more likely to evolve in the direction of gliding/flying.

Either is more accurate than completely making up it's legs or basing them on distantly related animals. I see nothing to suggest Longisquama wasn't a gliding animal, even if a presumably less specialized one for that task than Sharovipteryx; given it lacks the shrunken arms. And if it wasn't, long legs serve as more than just attachment points for membranes, they are also great for climbing and reaching between leaves and fronds, which I feel is in-line with Longisquama's elongated forelimbs.

Also, the first skeletal reconstruction of Longisquama you posted was by an artist named Jaime Headden, in this post he had a new reconstruction which has the limbs less erect, he explains why he considers his older reconstruction less plausible:

Even at the time I placed this image on this blog, I'd decided that evidence didn't favor an erect, archosaur-style posture. My reasons at the time were based on some details of the shoulder and hand, but these are not entirely consistent only with erect postures or digitigrade limbs.

For one, the shoulder suggests a lateral orientation for the humerus, the forearm presents a bowed ulna consistent with flexed elbows, and while the metacarpals are long, the carpals are small and irregular, and I am reminds of the feet of frogs and other tetrapods in which the metapodial elements contribute to digit length. Meaning, the limbs would be possibly splayed and plantigrade. Be aware this is speculation, and details of the original specimen are sparse as the preservation is terrible aside from the impressions, with the granularity of the slab extremely rough, meaning some elements are less differentiated than grains in the matrix.

I chose a skeletal to show the proportions, not any particular posture. The newer version shows what the author considers a more accurate posture, but in doing so it by necessity obscures the proportions of the arm.

Whether it's comfortable walking posture was sprawled or upright, quadruped or biped, it had really long arms, so it likely wasn't using them the same way lizards and Drepanosaurs do/did. I again go back to new world monkeys as a point of comparison, with long limbs for reaching between pieces of foliage. Though if it sprawled while on flat surfaces perhaps sloths would be a better analogy.