The rise and fall? of varanopids
Laurin and Didier 2025 wrote:
“The present study will focus on Varanopidae, which originated in the Pennsylvanian (Maddin et al., 2020), along with the OES grade. Varanopids, despite their modest diversity, are highly relevant because they survived the longest, well into the Capitanian (Modesto et al., 2011).”
Unfortunately, Laurin and Didier are not aware that traditional Varanopsidae split after Vaughnictis (not mentioned in the text or cladogram, Fig 1) into basal Synapsids (Fig 2) AND basal Protodiapsids (Fig 3).
“Varanopids have generally been considered to be early synapsids.”
LRT (subset Fig 1) varanopids ARE early synapsids.
LRT varanopids ARE ALSO early diapsids
– without ‘general consideration’.
* Lepidosaurormorphs also produce a diapsid skull architecture by convergence.
Figure 4. Subset of the LRT focusing on basal Archosauromorpha including Vaughnictis and Cabarzia nesting at the base of the Protodiapsid-Synapsid split. Note all the large varanopids nest together here in the Synapsida, separate from small varanopids in the Protodiapsida.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg?w=171″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg?w=582″ class=”size-full wp-image-35376″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg” alt=”Figure 4. Subset of the LRT focusing on basal Archosauromorpha including Vaughnictis and Cabarzia nesting at the base of the Protodiapsid-Synapsid split. Note all the large varanopids nest together here in the Synapsida, separate from small varanopids in the Protodiapsida.” width=”584″ height=”1027″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg?w=584&h=1027 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg?w=85&h=150 85w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg?w=171&h=300 171w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2019/01/archosauromorpha588-1.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />
Figure 4. Subset of the LRT focusing on basal Archosauromorpha including Vaughnictis and Cabarzia nesting at the base of the Protodiapsid-Synapsid split from 2018. Note all the large varanopids nest together here in the Synapsida, separate from small varanopids in the Protodiapsida.
Laurin and Didier wrote:
“We conducted two sets of analyses: one with the 21 varanopid taxa, and one with only
16 taxa (Ascendonanus, Cabarzia trostheidei, Anningia megalops, Microvaranops parentis and Elliotsmithia longiceps were excluded).”
Note the lack of outgroup taxa = Vaughnictis, in Laurin and Didier.
Figure 1. Varanodon, Varanops and Varanosaurus, three varanopids to scale along with the non-varanopids, Archaeothyris, Apsisaurus, Ophiacodon, Secodontosaurus and Haptodus.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg?w=300″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg?w=584″ class=”size-full wp-image-14965″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg” alt=”Figure 1. Varanodon, Varanops and Varanosaurus, three varanopids to scale along with the non-varanopids, Archaeothyris, Apsisaurus, Ophiacodon, Secodontosaurus and Haptodus.” width=”584″ height=”429″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg?w=584&h=429 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg?w=150&h=110 150w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg?w=300&h=220 300w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2014/02/varanops-varanodon1.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />
Figure 2 from 2014. Varanodon, Varanops and Varanosaurus, three varanopids to scale along with the non-varanopid basal synapsids, Archaeothyris, Apsisaurus, Ophiacodon, Secodontosaurus and Haptodus. Compare to figure 3.
Laurin and Didier asked,
“Why did varanopids become extinct much later than ophiacodontids, edaphosaurids and sphenacodontids?”
In the LRT (subset Fig 1) varanopids = protodiapsids are basal to archosauromorph diapsids (lepidosaurs nest elsewhere). Laurin and Didier are not aware of that hypothesis on interrelationships due to taxon exclusion and following out-dated traditions.
Figure 1. Figure 1. Basal Protodiapsida to scale. Diapsids in yellow. The synapsid Aerosaurus is grey.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg?w=171″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg?w=584″ class=”size-full wp-image-2410″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg” alt=”Basal Protodiapsida to scale.” width=”584″ height=”1026″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg?w=584&h=1026 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg?w=85&h=150 85w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg?w=171&h=300 171w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2011/10/protodiapsids5881.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />
Figure 3 from 2011. Basal Protodiapsida to scale. Diapsids in yellow. The synapsid Aerosaurus is grey. These varanopids are basal synapsids – basal to diapsids.
Laurin and Didier are academic experts on Varanopsidae.
This study shows they need to expand their taxon list to better understand the clade they focus on. They need to broaden their focus. Their lack of curiosity is, unfortunately, part and parcel for vertebrate paleontologists in general – a clade of scientist who take decades to acknowledge discoveries.
That’s why the LRT is here: minimizing taxon exclusion to recover overlooked interrelationships. The varanopid solution (Fig 1) appeared here over a decade ago.
References
Laurin M and Didier G 2205. The rise and fall of Varanopidae† (Amniota, Synapsida). Frontiers in Earth Science 13:1544451. doi: 10.3389/feart.2025.1544451
Source: https://pterosaurheresies.wordpress.com/2025/03/29/the-rise-and-fall-of-varanopids/
