The Mystery of Pterosaur Origins YouTube video

@seanmckelvey6618
3 months ago wrote in the comments section: “Don’t let David Peters see this video, he’ll lose his mind lmao. Jokes aside, great video on a really fascinating subject.”

from Dr Polaris = DrP
Starts @2:09 after DrP laments his finances for two minutes.

@2:42 DrP reports we don’t have any pre-bats = “completely absent in the fossil record.”

Not true. In the large reptile tree (LRT, 2338 taxa) we have pre-bats back to Ediacaran worms. Click here for the LRT.

@3:00 DrP reports pterosaurs make a sudden appearance in the Norian, Late Triassic, without precursors.

Not true. Again, the LRT has a long list of pre-pterosaurs.

@3:10 DrP reports both groups (bats and pterosaurs) diverged quite a long time before their appearances. That last common ancestor skeleton would not likely have been preserved.

That last common ancestor in the LRT is Silvanerpeton (Viséan).

Figure 1. Tropidosuchus and Lagerpeton compared to the new material (MCZ 101542). ” data-image-caption=”

Figure 1. Tropidosuchus and Lagerpeton compared to the new material (MCZ 101542).

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg?w=243″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg?w=584″ class=”size-full wp-image-53669″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg” alt=”Figure 1. Tropidosuchus and Lagerpeton compared to the new material (MCZ 101542).” width=”584″ height=”722″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg?w=584&h=722 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg?w=121&h=150 121w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg?w=243&h=300 243w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2021/03/lagerpeton588-1.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 1. Tropidosuchus and Lagerpeton compared to the new material (MCZ 101542).

@3:40 DrP reports ‘it has been very unclear how these flying reptiles evolved.’

The image correctly shows the pedal tracks of two lepidosaurs, Prorotodactylus and Rotodactylus, but incorrectly places them in the Ornithodira, prior to Lagerpetonidae, which likewise appears there by wishing it were so. Lagerpeton is related to Tropidosuchus (known from a complete skeleton, Fig 1) and these are related to proterochampsids in the LRT, which is the only cladogram that tests all competing taxa.

@3:45 DrP reports, ‘in the second half of the twentieth century, it became well established that pterosaurs were archosaurs (= crocs + dinos only in the LRT).

Aaaannndddd that’s why the origin of pterosaurs continues to befuddle workers. Pterosaurs are lepidosaurs.

@4:10 DrP reports the lagerpetids are basal to pterosaurs.

Funny thing: DrP shows what appears to be a small quadrupedal lepidosaur, Macrocnemus, in vivo on a moss-covered tree trunk here.

Sorry @9:39 this image is identified as Ixalerpeton (a bipedal protorosaur in the LRT).

Figure 1. Scleromochlus from ReptileEvolution.com. ” data-image-caption=”

Figure 1. Scleromochlus from ReptileEvolution.com.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg?w=300″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg?w=584″ class=”size-full wp-image-69605″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg” alt=”Figure 1. Scleromochlus from ReptileEvolution.com.” width=”584″ height=”375″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg?w=584&h=375 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg?w=150&h=96 150w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg?w=300&h=193 300w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2022/06/scleromochlus588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Scleromochlus from ReptileEvolution.com.

@4:30 DrP reports pterosaurs originated from ‘mostly bipedal’ ancestors. The image of Scleromochlus (Fig 2) as a straining quadruped with tiny hands and legs too short appears within seconds.

Scleromochlus is indeed an archosaur in the LRT, one of several similar basal bipedal crocodilomorphs. This was Michael Benton’s 1999 favorite, despite the vestigial fingers and lack of a pedal digit 5. DrP ignores these traits.

@8:10 DrP suggests dinosaurs and pterosaurs evolved from tiny adults, like Kongonaphon.

Not so in dinosaurs. Yes, so in pterosaurs. See Cosesaurus (Fig 3), Sharovipteryx, Longisquama and Bergamodactylus (Fig 3).

Figure 2. Bergamodactylus, the basal-most pterosaur compared to scale with Cosesaurus and Dromomeron. ” data-image-caption=”

Figure 2. Bergamodactylus, the basal-most pterosaur compared to scale with Cosesaurus and Dromomeron.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg?w=174″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg?w=584″ class=”size-full wp-image-85059″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg” alt=”Figure 2. Bergamodactylus, the basal-most pterosaur compared to scale with Cosesaurus and Dromomeron.” width=”584″ height=”1005″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg?w=584&h=1005 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg?w=87&h=150 87w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg?w=174&h=300 174w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/03/bergamodactylus-dromomeron588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Bergamodactylus, the basal-most pterosaur compared to scale with Cosesaurus and Dromomeron.

@8:15 DrP looks at a toe-touching Lagerpeton (Fig 1) restoration.

@9:54 DrP shows a restoration of Dromomeron, described as at 3 foot long taxon.

Figure 4. Venetoraptor to scale with Ixalerpeton, both apparent bipeds known from incomplete material.

@10:55 Venetoraptor is introduced.

In the LRT this is another bipedal protorosaur.

@11:55 DrP reports the finding of most early pterosaurs from Europe.

Hey, Cosesaurus (Fig 2) is from Europe! Lagerpetids are not.

@12:06 DrP reports, ‘Who knows? Perhaps one day the pterosaur equivalent of Archaeopteryx will be found. Although the chances of this are very slim.’

THIS is your lucky day, DrP, because in 2000 three taxa were shown in three phylogenetic analyses to be close to the most primitive pterosaur = Bergamodactylus: Cosesaurus, Sharovipteryx and Longisquama. You showed Rotodactylus tracks (Fig 2)  @3:40. These were made by cosesaurs in the Early to Middle Triassic.

Look for these traits in a pterosaur ancestor that can’t yet
fly because Bergamodactylus (Fig 2) and the above three taxa have these traits:
1) Multi-cusped back teeth.
2) Antorbital fenestra (by convergence with dinos).
3) Sternal complex = sternum + interclavicle + clavicles.
3) Anterioroly elongated ilium enclosing 4+ sacrals.
(4 Prepubes – these take over for the vestigial femoral retractors
4) Attenuated tail = loss of caudofemoralis retractors.
5) Simple hinge ankle joint (again, by convergence with dinos)

and the kicker:
5) that metapodial fifth toe that is otherwise only seen in cosesaurs and their giant relatives, the tanystropheids.

Plus – many more traits.

Figure 2. Rough comparisons of the Tribelesodon specimen assigned to Tanystropheus (Peyer 1931) compared to more complete specimens from Europe and China. ” data-image-caption=”

Figure 2. Rough comparisons of the Tribelesodon specimen assigned to Tanystropheus (Peyer 1931) compared to more complete specimens from Europe and China.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg?w=256″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg?w=584″ class=”size-full wp-image-14412″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg” alt=”Figure 2. Rough comparisons of the Tribelesodon specimen assigned to Tanystropheus (Peyer 1931) compared to more complete specimens from Europe and China.” width=”584″ height=”683″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg?w=584&h=683 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg?w=128&h=150 128w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg?w=256&h=300 256w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/12/tribelesodon-compared.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 5. Rough comparisons of the Tribelesodon specimen assigned to Tanystropheus (Peyer 1931) compared to more complete specimens from Europe and China.

Did you know
the tanystropheid, Tribelesodon (Fig 5), was originally considered a pterosaur due to the similarity in their feet? True fact.

Google any of the above taxa
and you’ll be taken to ResearchGate.net papers that hold all the details.

Gosh, Dr Polaris,
you’re making me feel like John Ostrom in the 1970s:

According to the Hartford Courant (2000), “In 1973, Ostrom broke from the scientific mainstream by reviving a Victorian-era hypothesis (see above) that his colleagues considered far-fetched: Birds, he said, evolved from dinosaurs. And he spent the rest of his career trying to prove it.” With the announcement of the first dinosaurs with feathers from China, Ostrom (then age 73) was in no mood to celebrate. He is quoted as saying, ““I’ve been saying the same damn thing since 1973, `I said, `Look at Archaeopteryx!’” Ostrom was the first scientist to collect physical evidence for the theory. Ostrom provoked a debate that raged for decades. “At first they said, `Oh John, you’re crazy,”’ Ostrom said in 1999.”

This is why paleontologists remain befuddled: they like to omit taxa.
New ideas take 20 year or more to take hold. Happens all the time.

References
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-1330

wiki/Cosesaurus
reptileevolution.com/cosesaurus.htm
reptileevolution.com/fenestrasauria.htm
reptileevolution.com/pterosaur-wings.htm