The ankle joint of Pterodaustro

Burlot et al take a close look at the tarsals
of Pterodaustro (Fig 1), an Early Cretaceous wading ctenochasmatid pterosaur with elongate, flexible, filter-feeding teeth.

Figure 1. The evolution of Pterodaustro from a sister to Ctenochasma. “Propterodaustro” , the Bamberg specimen, is a sister to the transitional taxon. As you can see, there is an increasing variety in this clade. ” data-image-caption=”

Figure 1. The evolution of Pterodaustro from a sister to Ctenochasma. “Propterodaustro” , the Bamberg specimen, is a sister to the transitional taxon. As you can see, there is an increasing variety in this clade.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/05/pterodaustro-evolution1.jpg?w=173″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/05/pterodaustro-evolution1.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-11071″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2013/05/pterodaustro-evolution1.jpg” alt=”Figure 1. The evolution of Pterodaustro from a sister to Ctenochasma. “Propterodaustro” , the Bamberg specimen, is a sister to the transitional taxon. As you can see, there is an increasing variety in this clade.” width=”584″ height=”1013″ />

Figure 1. The evolution of Pterodaustro from a sister to Ctenochasma. “Propterodaustro” , the Bamberg specimen, is a sister to the transitional taxon. As you can see, there is an increasing variety in this clade.

Unfortunately
the authors promote several traditional pterosaur myths. They wrote, “Pterosaurs, a taxon of extinct Mesozoic archosaurs,”

Adding taxa moves pterosaurs to the tanystropheid lepidosaurs
(Peters 2000. 2007).

“The hindlimb has been less studied.” “Thus, investigating the hindlimbs of pterosaurs may yield new phylogenetic and functional data.”

‘The catalog of pterosaur pedes for trackmaker identification” (Peters 2000) was not cited. This supports the curse of S Christopher Bennett who said to me, “You will not be published and if you are published you will not be cited.” The large pterosaur tree (LPT, xxx taxa) employs many hindlimb traits as data.

“It is conceivable that the ankle joint includes diagnostic information that might be useful to characterize the approximately 200 nominal species known in Pterosauria.”

Probably not. The ankle joint is similar in all pterosaurs. It is small and often crushed and enclosed in concretions. The rest of the pes and the rest of the pterosaur is more diagnostic, enabling lumping and splitting.

“Bennett (1996) suggested that eight small specimens assigned to “Pterodactylus” elegans represented juveniles conspecific with the large specimens assigned to
Ctenochasma gracile.”

“Suggested” doesn’t cut it. Bennett did not perform a phylogenetic analysis. Like Bennett, the authors need to understand that differences in pterosaurs represent phylogeny because hatchlings and juveniles have adult proportions. Ontogenetic isometry is another lepidosaur trait not duplicated in archosaurs.

“In this work, although comparisons will be made with all pterosaur taxa that allow it, special attention will be paid to Pterodactyloidea.” “the appearance of the Pterodactyloidea constitutes a major event in the evolution of Pterosauria.”

The authors do not realize that five clades of pterosaurs evolved to the pterodactyloid grade independently. Thus “Pterodactyloidea” is an invalid, falsified clade.

Figure 1. The V263 specimen compared to other Pterodaustro specimens to scale. ” data-image-caption=”

Figure 1. The V263 specimen compared to other Pterodaustro specimens to scale.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2017/04/pterodaustro-size-comparison2-588.jpg?w=203″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2017/04/pterodaustro-size-comparison2-588.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-26572″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2017/04/pterodaustro-size-comparison2-588.jpg” alt=”Figure 1. The V263 specimen compared to other Pterodaustro specimens to scale.” width=”584″ height=”862″ />

Figure 2. The V263 specimen compared to other Pterodaustro specimens to scale. Note the isometry of the lepidosaur growth strategy, not the allometry of archoaurs.

References
Burlot R et al (3 co-authors) 2024. The ankle joint of Pterodaustro guinazui. Acta Palaeontologica Polonica 69 (2): 329–350.