Martinez et al. 2021 say Taytalura ‘illuminates the origin of lizard-like reptiles’

The problem again is taxon exclusion.
By following traditions and excluding so many pertinent taxa, Martinez et al. 2021 elevated an ordinary Late Triassic rhynchocephalian taxon into a headline.

Actually Taytalura (Fig. 1) is pretty much like two other taxa
we already knew about: Diphydontosaurus and Gephyrosaurus (Fig. 1), neither of which is at the base of the Lepidosauromorpha, nor that close to the origin of the Lepidosauriformes or Lepidosauria in the large reptile tree (LRT, 1915+ taxa).

Figure 1. Taytalura from Martinez et al. 2021 compared to Diphydontosaurus and Gephyrosaurus. Diagram colors for Taytalura (at top) match the color pattern in Diphydontosaurus diagram (middle).

From the Martinez et al. abstract
“The early evolution of diapsid reptiles is marked by a deep contrast between our knowledge of the origin and early evolution of archosauromorphs (crocodiles, avian and non-avian dinosaurs) to that of lepidosauromorphs (squamates (lizards, snakes) and sphenodontians (tuataras)).

Not true in the LRT where lepidosaurs are well represented by many more extant taxa than non-bird archosauromorphs. Martinez et al. must be referring to fossil taxa, but why omit either fossil or extant taxa when both can be and should be employed in a cladogram.

Whereas the former include hundreds of fossil species across various lineages during the Triassic period1, the latter are represented by an extremely patchy early fossil record comprising only a handful of fragmentary fossils, most of which have uncertain phylogenetic affinities and are confined to Europe.

Affinities are resolved in the LRT. Europe does seem to be the center of early lepidosaurs, perhaps because that’s where so many lepidosaur paleontologists have been until recently.

“Here we report the discovery of a three-dimensionally preserved reptile skull, assigned as Taytalura alcoberi gen. et sp. nov., from the Late Triassic epoch of Argentina that is robustly inferred phylogenetically as the earliest evolving lepidosauromorph, using various data types and optimality criteria.

The authors are omitting Late Permian Lacertulus, Earliest Triassic Saurosternon, Late Permian Palaegama, Earliest Triassic Paliguana and other lepidosaurs in the LRT. The lepidosauriform, Tridentinosaurus is Earliest Permian (Fig. 2).

Figure 1. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama.
Figure 2. Taxa at the base of the Lepidosauria include Paliguana, Tridentinosaurus, Lanthanolania, Lacertulus, Gephyrosaurus, Megachirella, Lacertulus and Palaegama. Tridentinosaurus is Earliest Permian.

From the Martinez et al. abstract continued:
Micro-computed tomography scans of this skull reveal details about the origin of the lepidosaurian skull from early diapsids, suggesting that several traits traditionally associated with sphenodontians in fact originated much earlier in lepidosauromorph evolution.

The authors don’t realize tetrapods with a diapsid skull architecture are not monophyletic, as the LRT recovered years ago (2013) by simplly adding taxa. Some diapsid-grade taxa are archosauromorphs. Others are lepidosauriformes. In other words, the archosauromorph, Petrolacosaurus is not related to the lepidosauromorph, Taytalura.

Taytalura suggests that the strongly evolutionarily conserved skull architecture of sphenodontians represents the plesiomorphic condition for all lepidosaurs, that stem and crown lepidosaurs were contemporaries for at least ten million years during the Triassic, and that early lepidosauromorphs had a much broader geographical distribution than has previously been thought.”

According to results recovered by the LRT,
1. Taytalura has an abbreviated rostrum and a complete lower temporal bar. The plesiomorphic condition is a longer rostrum and no lower temporal bar.

2. Stem lepidosaurs go back at least to the Late Permian or perhaps the Early Permian (Fig. 2).

3. Broad distribution is probably correct given that Pangaea was a supercontinent in the Permian and Triassic.

Figure 2. Cladogram from Martinez et al. 2021. Click HERE for an enlargement. The authors have no anamniote nor amphibian-like reptile outgroup taxa. So they don’t realize Archosauromorpha split from Lepidosauromorpha by the Viséan. As a result their cladogram shuffles together unrelated taxa. Even so, Taytalura nests basal to Gephyrosaurus and Diphyodontosaurus here and in the LRT.

Publicity from Sci-news.com
A three-dimensionally preserved skull of a previously unknown Triassic-period reptile from Argentina illuminates the origin of lepidosauromorphs (lizards, snakes and tuataras).”

Not really. This skull nests basal to Diphyodontosaurus and Gephyrosaurus in the LRT, far from the origin of lepidosauromorphs (which includes turtles and amphibian-like reptiles in the LRT).

“The early evolution of lepidosauromorphs remains one of the largest knowledge gaps in reptile evolution.”

Not really. The LRT documents no gaps in the early evolution of lepidosauromorphs. Let’s try to make taxon exclusin a thing of the past. Colleagues: add taxa.

References
Martinez RN, Simoes TR, Sobral G and Apesteguia S 2021. A Triassic stem lepidosaur illuminates the origin of lizard-like reptiles. Nature https://doi.org/10.1038/s41586-021-03834-3

4 pakicetids enter the LRT starting with a new one: Phiomicetus (Gohar et al. 2021)

Gohar et al. 2021 described
a new “protocetid,” Phiomicetus anubis (Fig.1).

Figure 1. Skull of Phiomicetus from the Middle Eocene, nesting basal to pakicetids.

From the Gohar et al. abstract
“Over about 10 million years, the ancestors of whales transformed from herbivorous, deer-like, terrestrial mammals into carnivorous and fully aquatic cetaceans.

Two problems in one opening sentence here:
1. Whales (traditional order Cetacea) are not monophyletic.
2. No deer-like mammals are ancestral to any of the whales according to the the large reptile tree (LRT, 1915 taxa) which minimizes taxon exclusion. Overlooked Rhynchocyon (Figs. 5, 6) comes pretty close in limb morphology, but it is a leptictid, not an artiodactyl.

Figure 2. Andrewsiphius skull, humerus and femur with missing parts added based on Indohyus (small skeleton at left). This taxon moves out of whales with legs and nests now as a giant sister to Tenrec (upper left corner).

From the abstract continued
Protocetids are Eocene whales that represent a unique semiaquatic stage in that dramatic evolutionary transformation. Here, we report on a new medium-sized protocetid, Phiomicetus anubis gen. et sp. nov., consisting of a partial skeleton from the middle Eocene (Lutetian) of the Fayum Depression in Egypt.”

Always good to see new taxa!

Figure 3. Skeleton of Tenrec alongside restored skeleton model of Pakicetus.
Figure 3. Skeleton of Tenrec alongside restored skeleton model of Pakicetus. Someone should have recognized the similarity long before the LRT, yet years later, this still goes unnoticed by Gohar et al. 2021.

From the abstract continued
The new species differs from other protocetids in having large, elongated temporal fossae, anteriorly placed pterygoids, elongated parietals, an unfused mandibular symphysis that terminates at the level of P3, and a relatively enlarged I3.

Unique features of the skull and mandible suggest a capacity for more efficient oral mechanical processing than the typical protocetid condition, thereby allowing for a strong raptorial feeding style.

All good information, but now it is time for a phylogenetic analysis… The cladogram from Gohar et al. 2021 does not include any taxa basal to Pakicetus, so Phiomicetus can’t nest basal to Pakicetus and Andrewsiphius (Fig. 2) can’t nest with Tenrec (Fig. 2). You have to tell PAUP which taxon is the outgroup (= the basalmost taxon). If you tell PAUP Pakicetus is the outgroup taxon, then the other taxa that would have or might have nested basal to Pakicetus have to find another node to nest in. That’s why the LRT goes back to Ediacaran worms as outgroup taxa.

Figure 4. Cladogram from Gohar et al. 2021 nesting Phiomicetus within Pakicetus because no taxa basal to Pakicetus are offered. This is taxon exclusion based on assumption, rather than testing. Mammalodon is mistakenly included. It actually nests between hippos and desmostylians in the LRT. Andrewsiphius likewise should nest in the outgroup of these taxa.

From the abstract continued
Phylogenetic analysis nests Phiomicetus within the paraphyletic Protocetidae, as the most basal protocetid known from Africa.

In the LRT (subset Fig. 5) Phiomicetus also nests basal to protocetidae and pakicetidae. An overlooked clade of anagalids, leptictids and tenrecs are outgroups to Pakicetus in the LRT along with three pakicetids. The tenrecs, anagalids and leptictids are traditionally omitted from cladograms. Sometimes, hippos, cows and pigs are inserted as outgroup taxa. If only whale expert Phillip Gingerich had let The Triple Origin of Whales get published several years ago Gohar et al. could have used this validated set of outgroup taxa.

Figure 5. Subset of the LRT focusing on the tenrec-odontocete clade.

When Phiomicetus is added to the LRT
(Large Reptile Tree, 1915 taxa; subset Fig. 5) Protocetidae remains monophyletic, and Phiomicetus nests outside the Protocetidae in the proximal outgroup, the one including Indohyus (Fig. 2), Tenrec (Fig. 3) and relatives. Remingtonocetus (Fig. 8) and Georgiacetus were also added… and they nested with Phiomicetus. Protocetus (Fig. 9) was also added… and it nested with Zygorhiza in the archaeocetes. That tells us useful legs were absent, perhaps vestiges, in Protocetus.

Figure 7. Rhynchocyon, a living elephant shrew, is a living leptictid.
Figure 6. Rhynchocyon, a living elephant shrew, is a living leptictid.
Figure 4. Skeleton of the elephant shrew, Rhynchocyon. Note the digitigrade manus and pes, like those of basal artiodactyls.
Figure 7. Skeleton of the elephant shrew, Rhynchocyon. Note the digitigrade manus and pes, like those of basal artiodactyls, tenrecs and pakicetids.

From the abstract continued
Recovery of Phiomicetus from the same bed that yielded the remingtonocetid Rayanistes afer provides the first clear evidence for the co-occurrence of the basal cetacean families Remingtonocetidae and Protocetidae in Africa. The discovery of Phiomicetus further augments our understanding of the biogeography and feeding ecology of early whales.”

Andrewsiphius
(Fig. 2) is considered by Gohar et al. a member of the Remingtonocetidae (Fig. 8). The LRT nests Andrewsiphius as a tenrec, and Remingtonocetus basal to Pakicetus. The exclusion of valid more basal taxa is the problem in the Gohar et al. cladogram. Workers still consider the deer, cow and pig basal to whales, another embarrassing tradition borrowed and borrowed again by whale workers.

So where do odontocetes come from?
Anagalids, leptictids and tenrecs produced a bush of aquatic taxa with a large head and long snout: the pakicetids, archaeocetids and finally odontocetes. The extant leptictid, Rhynchocyon (Figs. 6,7), already has that long pointy snout and deer-like, whale-like ankles, but it has been traditionally omitted by whale experts. Same with the tenrecs.

Figure 8. Remingtonocetus skull in diagram and photo views. The photo shows the lateral process of the premaxilla contacting the anteriorly extended frontals, distinct from the diagram, which also gets rid of the left angle of the rostrum. This asymmetry improves echolocation sensing, as in tenrecs and odontocetes.
Figure 9. Protocetus skull. This first protocetid described (Fraas 1904) and recent addition to the LRT nests with Zygorhiza.

Protocetus was the first protocetid described
(Fraas 1904; Fig. 9) and nests with the archaeocete, Zygorhiza, in the LRT, far from the base of walking whales.

The traditionally omitted outgroups to whales in the LRT
(Fig. 5) appear to represent a novel hypothesis of interrelations. If there is a prior citation, please share it here so I can promote it. The LRT minimizes taxon exclusion, which makes it an ideal tool in cases like this where you want to know the outgroup to any vertebrate clade. That includes turtles, snakes and pterosaurs.

Sadly,
some paleontologists still hate it whenever the LRT recovers overlooked and omitted outgroups. Borrowing old and invalid cladograms, and trusting them, is a habit common among academic authors. That extends to authors of textbooks. According to one popular paleontologist who feels it necessary to occasionally harangue workers who do put in the effort to create wide-gamut cladograms, “It’s too much work.” So don’t expect things to change soon in paleontology.

References
Gohar et al. (7 co-authors) 2021. A new protocetid whale offers clues to biogeography and feeding ecology in early cetacean evolution. Proceedings of the Royal Society B https://doi.org/10.1098/rspb.2021.1368

Villaseñor-Amador et al. 2021 report Huehuecuetzpalli was bipedal in the Early Cretaceous

Not sure I agree with this,
even though this hypothesis fits nicely into the hypothesis by Peters (2000a, 2000b, 2007) that many (but not all) Huehuecuetzpalli (Fig. 1) phylogenetic descendants also had a facultative to obligatory bipedal gait. These taxa include Langobardisaurus to Tanystropheus, to Macrocnemus (Fig. 2) to Cosesaurus (Fig. 3), Sharovipteryx, Longisquama and pterosaurs (Fig. 4).

Early to Middle Triassic tracks
matching the pes of Cosesaurus, named Rotodactylus (fig. 3, Peters 2000b), show the transition to bipedal locomotion happening 100 million years earlier in lepidosaurs. Early Cretaceous Huehuecuetzpalli might have been a wee bit too soon (phylogenetically) and too late (chronologically) for the first instance of a bipedal lepidosaur.

Huehuecuetzpalli
Figure 1. The father of all pterosaurs and drepanosaurs, Huehuecuetzpalli.

Usually bipedal lizards
have a longer neck (for reasons that escape me) and an extra sacral or three to anchor a slightly to greatly elongate ilium, as found in a little Macrocnemus, the BES SC 111 specimen (Fig. 2) and littler Cosesaurus (Fig. 3).

Figure 5. The BES SC 111 specimen of Macrocnemus with dorsal frills like Litorosuchus.
Figure 2. The BES SC 111 specimen of Macrocnemus with dorsal frills.

From the highlights and abstract

• The extinct lizard Huehuecuetzpalli mixtecus had a bipedal gait.
• The ancestral condition in lizards is inferred to be terrestrial.
• The ancestral condition in lizards is inferred with hindlimbs longer than forelimbs.
• The bipedal gait was common in lizards since the lower Cretaceous.

Abstract:
“Representative locomotion types in lizards include terrestrial, arboreal, grass swimmer, sand swimmer and bipedal. Few studies explain the locomotion habit of extinct lizards, and even less asses [= fewer assess] those of bipedal ones. Here, we use quantitative methods to infer the type of locomotion of two Albian Mexican lizards (Lower Cretaceous) and three Cretaceous lizards from Brazil, North America and Spain, assessing the similarities of the hindlimb-forelimb length ratio amongst extinct and extant species. Additionally, an ancestral character state reconstruction analysis was performed, to evaluate the evolution of lizard locomotion habits. The species Huehuecuetzpalli mixtecus was bipedal while Tijubina pontei was facultative bipedal, Hoyalacerta sanzi, Tepexisaurus tepexii and Polyglyphanodon sternbergi cannot be differentiated amongst terrestrial or arboreal with the approach used in this work. The ancestral character state reconstruction analysis showed a terrestrial ancestral locomotion type, with a basal character state of hindlimbs longer than forelimbs. Equal length between hind and forelimbs appear to be a derivate state that evolved multiple times in lizard evolutionary history.

Figure 1. CLICK TO ENLARGE. Cosesaurus reconstructed with enlarged parts of interest including a pes (foot) matching a Rotodactylus track. Here the pelvis is reconstructed according to figure 3. Shown here about life-size.
Figure 3. CLICK TO ENLARGE. Cosesaurus reconstructed with enlarged parts of interest including a pes (foot) matching a Rotodactylus track. Here the pelvis is reconstructed according to figure 3. Shown here about life-size.

Taxon exclusion mars this study.
The authors think Huehuecuetzpalli is an early member of Squamata and Iguania. It is not. This genus has been historically hard to classify due to taxon exclusiion.

The authors describe their methods.
“Photographs were taken of the forelimbs (humerus, radius, ulna) and hindlimbs (femur, tibia, fibula) of 36 existing species of lizards, all with their respective measurement scale.” “The hindlimb-forelimb length ratio was calculated as the sum of the femur and tibia longitudes (hindlimb length) divided by the sum of the humerus and ulna longitudes (forelimb length), in mm.” Huehuecuetzpalli scored a 1.58. Bipedal lizards scored 1.42 to 1.9 with a 1.85 median. “This led us to infer that Huehuecuetzpalli mixtecus was a bipedal lizard supported by all analyses, like extant lizards Basilicus, Laemanctus, and Corytophanes.”

The evolution of the pterosaur tail beginning with a basal lizard, Huehuecuetzpalli.
Figure 4. The evolution of the pterosaur tail beginning with a basal lizard, Huehuecuetzpalli.

Longer hind limbs do not necessarily make a lepidosaur a biped.
Cosesarus has similar hind limbs to Huehuecuetzpalli (Fig. 4), and we have cosesaur tracks (ichnite: Rotodactylus) that show it as a quaruped and narrow-gauge biped. Then again, Sharovipteryx, Longisquama and Bergamodactylus (Fig. 4) were obligate bipeds. Their stem-like, locked-down coracoids indicate they were flapping, not walking, with their forelimbs.

References
Villaseñor-Amador D, Suárez NX and Crus JA 2021. Bipedalism in Mexican Albian lizard (Squamata) abd the locomotion type in other Cretaceous lizards. Journal of South American Earth Sciences 109:103299.
Peters D 2000a. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Riv. It. Paleo. Strat. 106(3): 293-336.
Peters D 2000b. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7: 11-41.
Peters D 2007. The origin and radiation of the Pterosauria. Flugsaurier. The Wellnhofer Pterosaur Meeting, Munich 27.
Peters D 2011. A catalog of pterosaur pedes for trackmaker identification. Ichnos 18(2): 114-141.
Peters D 2017 unpublished accessible here. Cosesaurus aviceps, Sharovipteryx mirabilis and Longisquama insignis Reinterpreted.

13 strange things about the new tapejarid, ‘Tupandactylus navigans’ GP/2E 9266

It’s always wonderful to see a new, complete pterosaur skeleton.
This one comes with a backstory that is making the rounds. Here we’ll talk about the specimen itself, GP/2E 9266 (Beccari et al. 2021; Early Cretaceous; Figs. 1-5), presently assigned to the name Tupandactylus navigans, a putatitve relative of Tupandactylus imperator.

Figure 1. The new Tupandactylus compared to the old Tupandactylus to scale. Both are considered adults. Note the similarity between Brazilian and Chinese tapejarids.

The first strange thing about GP/2E 9266
is how much it resembles Tupandactylus (known from a partial skull only)… except for size (Fig. 1). The authors considered both to be adults. From the abstract: “The specimen can be assigned to Tupa. [= Tupandactylus] navigans due to its vertical supra-premaxillary bony process and short and rounded parietal crest.” Let’s stop assigning taxa based on a few traits. That’s “Pulling a Larry Martin“. Case in point: See the next paragraph.

The second strange thing about GP/2E 9266
is how it doesn’t nest with Tupandactylus in the Large Pterosaur Tree (LPT, 260 taxa). Instead it nests with a similarly-sized Chinese taxon, ZMNH M 8131 (Fig. 1), closer to the base of the Tapejaridae.

Figure 2. Tupandacatylus navigans (GP/2E 9266) in situ and µCT scans produced by Beccari et al. 2021. Note the lack of a prepubis and the extremely slender ventral process of the pubis, likely incapable of supporting a prepubis.

The third strange thing about GP/2E 9266
is that tall headcrest. It leans anteriorly, distinct from other, otherwise similar, crests. The authors found no posteriorly projecting process, but this is often broken off in fossils. There is an impression that matches the missing bone (Fig. 3). Speculative, but there it is, an impression.

Figure 3. Skull of Tupandactylus navigans (GP/2E 9266) from Beccari et al. 202. Colors added here. Compare to the original identity of skull bones by Beccari et al. in figure 2.

The fourth and fifth strange things about GP/2E 9266
is it has one parasagittally expanded neural spine. The authors report that five vertebrae form a notarium, different than any other tapejarid… and the medial scapula is not modified to articulate with it. Likewise the ventral coracoid is not expanded, as in related taxa.

The sixth and seventh strange thing about GP/2E 9266
is the lack of a prepubis… and the extremely slender ventral process of the pubis, likely incapable of supporting a prepubis.

Figure 4. The pes of the GP/2E 9266 specimen as originally figured by Beccari et al. 2021 and revised here. Comparison to the other metatarsus shows the correct lengths overlooked by Beccari et al. who also renamed the phalanges on toe 4, not realizing that two phalanges were fused to become one.

The eighth strange thing about GP/2E 9266
is the fusion of pedal phalanges 4.2 and 4.3 (Fig. 4). Beccari et al. also overlooked the fifth metatarsal and its two digits. The authors mistakenly wrote: “As in all later-diverging pterodactyloids, there are only four pedal digits.”

BTW, I’ve never seen distal tarsals on any tetrapod or pterosaurs like those shown in Beccari et al. (red elements in Fig. 4). Let’s leave those be for the time being.

Figure 5. Wing of the GP/2E 9266 specimen as originally illustrated by Beccari et al. (left) and repaired here (right).

The ninth strange thing about GP/2E 9266
is the authors flipped the wing finger upside-down with the leading edge trailing (Fig. 5). They also did not create horizontal stabilizers of the sprawling hind limbs (Fig. 6). Pterosaurs are such perfect natural inventions. Don’t leave the hind limbs dangling uselessly. Remember Sharovipteryx!


Figure 6. The GP/2E 9266 specimen reconstructed in dorsal view by Beccari et al 2021 and modified here (top half) to reflect the sprawling femora.

The tenth strange thing about GP/2E 9266
is the odd quadrupedal pose Beccari et al. put their reconstruction into (Fig. 7). Sure some pterosaurs walked around quadrupedally and left tracks. These were all beachcombers, seeking food in shallow waters. Tapedjarids are not members of those clades. Don’t generalize and make all pterosaurs awkward quadrupeds. Look at each one individually. Bipedal pterosaur ancestors were able to flap before they were pterosaurs. That was the initial attraction, together with crests.

Figure 7. Pterosaurs were like birds, right? Able to flap their forelimbs since before they were pterosaurs. A Tapejara prepubis is added here, but is not present in the GP/2E 9266 specimen.

The eleventh strange thing about GP/2E 9266
is the gracile pteroid. Really slender, more so than I’ve seen in pterosaurs.

The twelfth strange thng about GP/2E 9266
is the longer than typical phalanx 4.1, extending to the proximal ulna when the wing is folded (Fig. 7). Beccari et al. got things mixed up when they reported, “first wing phalanx length to metacarpal IV length in GP/ 2E 9266 = 0.58.”

The thirteenth strange thing about GP/2E 9266
is the tiny size of the foot.

Beccari et al. performed a phylogenetic analysis
(unfortunately, derived from previous studies). The authors reported, “The holotype of Tupa. navigans SMNK PAL 2344 was initially coded as a separate OUT, but no character differed from the scoring of GP/2E 9266. Therefore, the phylogenetic position of Tupa. navigans was accessed through the scoring of GP/2E 9266 using the character-taxon matrix of, composed by 64 taxa (including the new specimen) and 150 discrete characters.” This is why convergence can be so difficult to deal with. What can be scored of the two skulls are virtually identical. In the Beccari et al. analysis the Huaxiapterus corollatus specimen ZMNH M8131 (Fig. 1) nests in a polytomy with other Chinese pterosaurs separate from a sister polytomy of Brazilian pterosaurs. Since no one in Beccari et al. published comparable reconstructions or figures of related taxa (as in Fig. 1), other than some colorful silhouettes, we can assume they did as they said they did: borrowed data, never traced taxa, trusted scores and taxon lists.

Beccari et al. have outdated notions regarding pterosaur ontogeny
and bone fusion. They seek the fusion of elements as a ‘sign’ of maturity, as in the archosaurs and dinosaurs in their outdated cladogram. Adding taxa shows this notion is false. Fusion is entirely phylogenetic. When you look at enough taxa you learn that immature and late-stage embryo pterosaurs are identical to adults, except for an 8x difference in overall size, as in the lepidosaurs missing from the Beccari et al. cladogram.

Flight?
The authors report, “The relatively longer forelimbs and the long cervical series may argue for a terrestrial foraging lifestyle.” “This could indicate that the aberrant crest may have restricted Tupa. navigans to short-distance flights, such as to flee from predators.” Sure the wing finger is skinny and phalanx 4.4 is short, but this taxon is far from flightless.

References
Beccari V, Pinheiro FL, Nunes I, Anelli LE, Mateus O and Costa FR 2021. Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade. PLoS ONE 16(8): e0254789. https://doi.org/10.1371/journal.pone.0254789

wiki/Tupandactylus
eptileevolution.com/tapejaridae.htm

The splitfin flashlightfish, Anomalops, enters the LRT


This taxon was difficult to nest.
The text below represents my third try.
(It’s okay to make mistakes. Keep trying. Not trying gets you nowhere.)

Figure 1. The splitfin flashlightfish, Anomalops, showing off its suborbital light organ.

Anomalops katoptron (Kner 1868; 35cm; Figs. 1, 2) is the extant splitfin flashlightfish nesting basal to jacks in in the large reptile tree (LRT, 1911+ taxa), like the two Seriola taxa (Fig. 7). Anomalops currently arises from a plesiomorphic Palaeocene taxon close to Massamorichthys (Fig. 5).

Anomalops has a light-emitting organ
filled with luminious symbiothic bacteria beneath the large eyeball. This organ blinks 90x a minute by flipping down (Fig. 2). It uses those twin ‘headlights’ to detects zooplankton prey in the light-less depths.

Figure 2. The light organ folds quickly, 90x each minute. Related taxa don’t have anything likes this unique organ… so far. Adding taxa always solves problems like this.

Note the tall ascending process
of the premaxilla (Fig. 3), the tiny nasal and lack of a parietal, the fusion of the frontal and postparietal, among several other synapomorphies. The teeth are extremely tiny.

Figure 3. Skull of Anomalops in layers from Johnson and Rosenblatt 1988, colorized here.

Where does the light organ evolve from?
It sits in the large orbit along with the eyeball. A related and recently added taxon, the pineconefish (Monocentris, Fig. 4) has something similar, but not as distinct. A more plesiomorphic Monocentris relative, Massamorichthys (Fig. 5), is known from Palaeocene fossils. I’ll add taxa to make this transition more gradual as I find them.

Figure 4. Monocentris is the extant pineconefish.
Figure 6. Maasamorichthys with colors added.
Figure 3. Seriola rivoliana is the high fin Amberjack is basal to gobies and tetraodontiformes.
Figure 7. Seriola rivoliana is the high fin Amberjack basal to gobies and tetraodontiformes.

References
Johnson GD and Rosenblatt RH 1988. Mechanisms of light organ occlusion in flashlight fishes, family Anomalopidae (Teleostei: Beryciformes), and the evolution of the group. Zool J Linnean Soc. 1988;94: 65–96.
Kner R 1868. Über einige Fische aus dem Museum Sitz.. B. Akad. Wiss. Wien, Math.-Naturw. Kl., 58 (1), 26

wiki/Splitfin_flashlightfish
wiki/Beryciformes

University textbook, Vertebrate Paleontology, by Michael J Benton: a focused review p6 – diapsids and turtles

A traditional problem in paleontology is the mistaken belief
that all reptiles with a diapsid skull morphology are members of a single clade: the traditional Diapsida. Adding taxa splits this traditional clade in two. Members of the Lepidosauramorpha developed this skull morphology independently from members of the Archosauromorpha in the large reptile tree (LRT, 1908+ taxa). In the LRT, this latter clade can continue to be called Diapsida because the clade name Lepidosauriformes is suitable for the other convergent clade in the new Lepidosauromorpha (traditional definitions apply).

Unfortunately,
the university textbook, Vertebrate Paleontology, 4th ed by Michael J Benton follows invalid tradition as Benton’s cladogram (Fig. 1) presents a monophyletic Diapsida. The Benton cladogram features too few taxa and all are suprageneric. Unfortunately, this is what they teach at the university level. Amateurs have had to step in where professors have dropped the ball, relying on others to do the work because, well… this is a lot of work. And there is no reward or book royalties, only vilification.

Figure 1. Cladogram from Benton 2014. Color added for clades in the Archosauromorpha in the LRT. Too few taxa here leads to major misunderstanding.
Figure 1. Cladogram from Benton 2014. Color added for clades in the Archosauromorpha in the LRT. Too few taxa here leads to major misunderstanding and a shuffling of clades. Note the turtles nest close to sea reptiles (Enaliosauria) and Lepidosauriformes. Compare to Figure 2.

As documented ten years ago,
the reptiles (= amniotes) had their first dichotomy shortly after the genesis of the amnion. That dichotomy split reptiles into Archosauromorpha and Lepidosauromorpha. Benton 2014 was not aware of that division, as discussed earlier.

Figure 2. From Benton 2014. Here there are no intervening or transitional taxa between turtles and pterosaurs. This is a mistake that will confuse students. Adding taxa cures this problem. Compare to figure 1, also from Benton 2014 where turtles do not nest with pterosaurs. Internally inconsistent.

The following two subsets of the LRT
document the basal members of the diapsid-grade Lepidosauriformes within the Lepidosauromorpha (Fig. 3) and basal members of the diapsid-grade Diapsida within the Archosauromorpha (Fig. 4).

Figure 5. Subset of the LRT focusing on the origin of the Lepidosauriformes.
Figure 3. Subset of the LRT focusing on the origin of the Lepidosauriformes. See figure 5 for the pareiasaur – turtle clade phylogenetically just prior to this one.
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.
Figure 4. Subset of the LRT focusing on basal Archosauromorpha 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.

Moving on from ‘diapsids’ to ‘turtles’
Benton 2014 was clueless with regards to turtle outgroups and internally inconsistent. In figure 1 (above) Benton’s turtles nest close to enaliosaurs (sea reptiles) and lepidosaurs. This compares to figure 2 (above) where Benton’s turtles nest close to pterosaurs and dinosaurs. So Benton presents a cladogram (Fig. 2) in which there are no taxa between turtles and pterosaurs. Just let that sink in. This is taught in university classrooms.

Figure 1. Carbonodraco enters the LRT alongside another recent addition, Kudnu, at the base of the pareiasaurs + turtles.
Figure 5. Subset of the LRT focusing on turtles and their ancestors within the Lepidosauromorpha just prior to figure 3.

By contrast
in the LRT (subset Fig. 5) turtles are derived twice from pareiasaurs, once for softshell turtles and again for hardshell turtles (Fig. 6). The LRT tests all competing candidates. Oddly, considering the widespread interest in turtle origins, no other published cladograms include the pertinent taxa recovered by the LRT. By excluding pertinent outgroup taxa, Benton 2014 follows recent misguided attempts at solving turtle origins with cherry-picked taxa. The LRT accidentally stumbles upon dual turtle ancestry by simply adding taxa and letting the software decide the tree topology. The critical mass of taxa in the LRT seems to have been reached: Turtles have not migrated from small horned pareiasaurs since then.

Figure 6. Bunostegos, Elginia and Meiolania to scale showing the origin of hard shell turtles.
Figure 6. Bunostegos, Elginia and Meiolania to scale showing the origin of hard shell turtles.

Since Benton once again nested pterosaurs with dinosaurs
and Scleromochlus (Figs. 1, 2) here are the taxa from the LRT (Fig. 7) that nest closer to pterosaurs when they are given the opportunity to do so (see Peters 2000, 2007) and are correctly scored from first-hand observation, tracing and reconstruction. This is what you get when you create a cladogram, admit a wide gamut of taxa and let the taxa nest themselves.

Figure 2. Subset of the LRT focusing on the relatives of Macrocnemus.
Figure 7. Subset of the LRT focusing on the relatives of pterosaurs. These are all lepidosaurs, far from dinosaurs that keep cropping up in university textbooks (Figs. 1, 2).

References
Benton MJ 2014. Vertebrate Paleontology 4th ed. Wiley-Blackwell 480pp.
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.

wiki/Diapsid

https://www.researchgate.net/publication/328388481_The_dual_origin_of_turtles_from_pareiasaurs

https://www.researchgate.net/publication/328388115_Cosesaurus_aviceps_Sharovipteryx_mirabilis_and_Longisquama_insignis_Reinterpreted

Another ‘origin of pterosaurs’ paper once again omits pterosaur precursors: Baron 2021

Summary from Baron 2021:
“the clade Pterosauria belongs with Lagerpetidae as part of a broader Pterosauromorpha that then, with Dinosauriformes, falls within Ornithodira.”

And for illustrations
Baron republishes images of Dimorphodon from 1870.

From the abstract
“Our understanding of the pterosaurs’ place within the reptilian lineage has had a long and complex history. The unusual morphology of pterosaurs, which is inextricably linked to their habit of powered flight, has generated numerous proposals over the years regarding their exact origin and systematic position. Though it was concluded early on in pterosaur research history that these animals represented a group of derived flying reptiles, their exact origination remained mysterious for a long time and is still somewhat controversial. A rough consensus has now been reached that pterosaurs are derived archosaurs and are likely close relatives of the dinosaurs, united with them in the clade Ornithodira, though some still challenge this view. The anatomical evidence in support of this position close to Dinosauria is also admittedly fairly limited at present, largely owing to a lack of any clear-cut transitional ‘proto-pterosaur’ taxa (albeit that some fragmentary specimens have been suggested to represent exactly this). Differing hypotheses have also recently been put forward as to the exact interrelationships between the pterosaurs and other non-dinosaurian and dinosaurian ornithodirans. Here the previous hypotheses of where pterosaurs fit into the reptilian lineage and the anatomical evidence in support of the current hypotheses are reviewed. Results of new analyses are included that looked to test the origin and systematic position of the Pterosauria using an expanded version of a large anatomical dataset of archosaurs, within which several previously unconsidered early pterosaur taxa and a suit of new anatomical characters were considered. The analyses in this study support the close affinities between pterosaurs and dinosauriforms within Ornithodira; Pterosauria is recovered as the sister-taxon to Lagerpetidae. Such a result suggests that the clade Pterosauria belongs with Lagerpetidae as part of a broader Pterosauromorpha that then, with Dinosauriformes, falls within Ornithodira. The anatomical evidence in support of this position within Ornithodira is also discussed in detail.”

This is my reply, after receiving the PDF from author Matthew Baron.

Thank you, Matthew. And, of course, I will not share this PDF.

Some uncited research that supports the fenestrasaur hypothesis:
http://davidpetersstudio.com/papers.htm

Peters 2000 was my first paper and as a naive freshman, I made several errors, including the assignment of the tanystropheids to the prolacertiformes, corrected in Peters 2007 and in later works listed above and below.

http://reptileevolution.com/reptile-tree.htmhttp://reptileevolution.com/cosesaurus.htmhttp://reptileevolution.com/sharovipteryx.htmhttp://reptileevolution.com/longisquama.htmhttp://reptileevolution.com/MPUM6009.htm

There is a movement to keep Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama out of pterosaur origin cladograms, and you followed it. I can’t understand the motivation for doing so. Please share with me when you have an opportunity.

re: My freshman attempt (Peters 2000): Here is a link to a more mature researchgate.net paper the referees did not want published.

https://www.researchgate.net/publication/328388115_Cosesaurus_aviceps_Sharovipteryx_mirabilis_and_Longisquama_insignis_Reinterpreted

You can’t shed light on the origin of pterosaurs by deleting pterosaur precursors. 

Give yourself time to see the pertinent fossils, as I have. Cosesaurus has a prepubis, a pteroid, a five vertebrae sacrum, elongated ilium, a precursor sternal complex (completed in Longiquama) and have locked-down elongate coracoids, a trait shared only with flapping tetrapods (bats substitute a long clavicle). See link above.

Finally, remind yourself that a small Tanystropheus was originally and mistakenly considered a pterosaur because it had dimorphic teeth and pterosaur-like feet (that metapodial fifth toe is what attracted my attention to Cosesaurus in the first place).

Thank you for the one citation. Sorry you missed the others.

Don’t borrow cladograms and reconstructions traced from fossils. Step up to the plate and create your own, as I have.

Best regards, and better luck next time.
David Peters

Figure 1. CLICK TO ENLARGE. Cosesaurus reconstructed with enlarged parts of interest including a pes (foot) matching a Rotodactylus track. Here the pelvis is reconstructed according to figure 3. Shown here about life-size.
Figure 1. CLICK TO ENLARGE. Cosesaurus reconstructed with enlarged parts of interest including a pes (foot) matching a Rotodactylus track. Here the pelvis is reconstructed according to figure 3. Shown here about life-size.

Darren Naish often accuses me of ‘bad methodology’.
In this case (like Hone and Benton 2007, 2008), Matthew Baron 2021 did not see the pertinent fossils nor did he include the pertinent fossils in his borrowed cladogram. Is that what Naish would consider ‘good methodology’? It will be interesting to see if Naish reserves his accusations to colleagues and spends them only on outsiders.

References
Baron MG 2021. The origin of pterosaurs. Earth-Science Reviews 221: 103777
https://doi.org/10.1016/j.earscirev.2021.103777
Hone DWE and Benton MJ 2007. An evaluation of the phylogenetic relationships of the pterosaurs to the archosauromorph reptiles. Journal of Systematic Palaeontology 5:465–469.
Hone DWE and Benton MJ 2008. Contrasting supertree and total evidence methods: the origin of the pterosaurs. Zitteliana B28:35–60.

University textbook, Vertebrate Paleontology, by Michael J Benton: a focused review p5 – synapsids

The university textbook, Vertebrate Paleontology (4th ed),
by professor Micahel J Benton (2014) promotes many old myths that need to be nipped in the bud before another class of students is exposed to them. The first four parts of this focused review, of Benton 2014 were published over the last few days.

Today we tackle two decades-old myths
surrounding the clade Synapsida that were kept alive in Benton 2014 (Figs. 1, 3).

Myth number 1:
The first dichotomy after the genesis of the amnion was the splitting of amniotes between Synapsida and Reptilia (Fig. 1). This myth is supported by Benton 2014.

Figure 1. Basal amniote cladogram from Benton 2014. Due to taxon exclusion Benton has no idea that amniotes split prior to the Viséan into Archosauromorpha (orange) and Lepidosauromorpha.
Figure 1. Basal amniote cladogram from Benton 2014. Due to taxon exclusion Benton has no idea that amniotes split prior to the Viséan into Archosauromorpha (orange) and Lepidosauromorpha.

Simply by adding taxa,
as in the large reptile tree (LRT, 1908+ taxa; subset Fig. 2) the original dichotomy following the genesis of the amnion was the split between Archosauromorpha and Lepidosauromorpha. That preceded that dichotomy that introduced the Synapsida by tens of millions of years. Amniota is a junior synonym for Reptilia.

Figure 2. Subset of the LRT focusing on basal lepidosauromorphs and Diadectes. Note the splitting of Archosauromorpha (see figure 3) comes very early. The Caseasauria (in green) nests far from the Synapsida when pertinent taxa are added. Benton was comfortable with the traditional nesting.

Within the Archosauromorpha,
a long line of amphibian-like and more slender amniotes preceded the split between Synapsida and Protodiapsida (Fig. 3). So Benton was short more than a dozen taxa.

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.
Figure 3. 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.

Myth number 2:
“The clade Caseasauria nests within the Synapsida.” This myth going back decades was based on taxon exclusion and was promoted and extended by Benton 2014 (Fig. 4). This myth was invalidated in 2011 here. Caseasauria are Lepidosauromorpha, nesting with similar taxa that share a lateral temporal fenestra (Figs. 2, 5).

Figure 4. From Benton 2014, color overlay added here. Caseasauria does not nest within Synapsida in the LRT (Fig. 4).

To test this hypothesis
All you have to do is test taxa together that have not been tested together before. That permits caseasaurs to nest with more parsimonious sister taxa, far from the Synapsida, closer to Milleretta, Feeserpeton and Australothyris (Fig. 5).

Do not be among those who trot out
the four or five cartoon skulls with one, two or no holes in the temple and cheek. That is trait-based taxonomy and subject to convergence, something Benton should be aware of if there’s going to be a 5th edition. Only the Last Common Ancestor method should be used to determine clades and relationships.

Figure 5. In the LRT Case and the Caseasauria is related to these taxa, Australothyris, Eothyris and Milleretta, not any synapsid. Note the convergent synapsid opening in this lepidosauromorph.

Seems like MJ Benton took every easy way out (so far)
following tradition, keeping within the status quo, shielding himself from competing hypotheses, failing to test over a wider gamut of taxa, ascribing to gene studies. Since Benton decided to write ‘the book’ on vertebrate paleontology he could have at least delved a little deeper into the subject, keeping an open mind, testing options for himself, be brave enough to stand for what is right rather than produce what is acceptable in the market for textbooks.

References
Benton MJ 2014. Vertebrate Paleontology 4th Edition Wiley-Blackwell 480 pp.

tolweb: Synapsid Classification
wiki/Caseasauria

The usual pterosaur myths repeated by Jagielska and Brusatte 2021

I wrote this comment
in the Cell Press Current Biology Magazine comments section after seeing the link in Facebook. This further amplifies my earlier hypothesis (re: MJ Benton and his textbook and D Naish and M Witton on hatchlings) that authors are not doing their own work on pterosaurs, but cherry-picking myths and cladograms from preferred authors.

This time
yet another student and professor (Jagielska and Brusatte 2021) join forces to spread old pterosaur myths as fact.

Nataliia Jagielska: You should not have written this academic paper. The first sentence: “Pterosaurs are closely related to dinosaurs,” is a myth. Phylogenetic analysis indicates pterosaurs are lepidosaurs. Your illustration of the Zittel wing of Rhamphorhynchus (in gray) is correct, with a membrane stretched between the elbow and wingtip, but then you used your imagination to stretch the membrane to the ankle. The pteroid is not unique to pterosaurs, but is shared with Cosesaurus, Sharovipteryx and Longisquama, all pterosaur sister taxa. Their is no mystery to their origin. These taxa share uropatagia, sternal complexes, elongate locked-down coracoids, antoribital fenestra, etc. You wrote, “there was yet another membrane extending between the legs.” This is a myth based on Sordes. That’s the dismembered left main wing membrane. The right membrane looks like the Zittel wing. The actual uropatagia are gracile behind each hind limb. The quadrupedal launch is a myth based on contact of the wing spar (fourth finger) with the substrate. That never happens and if attempted delays wing unfolding and the first flap long past the moment of impact after a face plant crash. The enormous azhdarchids were enormous because they were flightless, as vestigial distal wing phalanges indicate. Darwinopterus was not a transitional fossil, but a dead end. There were four pterodactyloid-grade clades. You discover this by simply adding taxa. Run your own analysis next time. Add taxa that were proposed twenty years ago. You’ll see for yourself. More details, citations and links therein here: http://reptileevolution.com/cosesaurus.htm

References
Jagielska N and Brusatte SL 2021. Primer Pterosaurs. Cell Press Current Biology Magazine. R984 Current Biology 31, R973–R992, August 23, 2021 link here.

University textbook, Vertebrate Paleontology, by Michael J Benton: a focused review p4 – basal amniotes

The more one examines Vertebrate Paleontology (Benton 2014)
(the university-level textbook), the more one can understand the current state of disorder and resistance to repair. If this is what professors are teaching at the university level, then we are in the Dark Ages of magical thinking fueled by reliance on invalid deep time gene studies, permission at the highest levels to omit pertinent citations, suprageneric taxon inclusion and generic taxon exclusion. Untenable results were cited and republished by Benton without his professional criticism or testing (Fig. 1). In other words, Benton went with ‘the flow.’

Parts 12 and 3 of this ongoing review of Benton 2014 were posted over the past few days.

Today let’s look at the genesis and early radiation of reptiles (= amniotes)
as published in Benton 2014 (Fig. 1). His cladogram carries decades of tradition that is easily overturned by simply adding taxa, as in the large reptile tree (LRT, 1908+ taxa; subsets Figs. 3,4).

Figure 1. Basal amniote cladogram from Benton 2014. Due to taxon exclusion Benton has no idea that amniotes split prior to the Viséan into Archosauromorpha (orange) and Lepidosauromorpha.
Figure 1. Basal amniote cladogram from Benton 2014. Due to taxon exclusion Benton had no idea that amniotes split prior to the Viséan into Archosauromorpha (orange) and Lepidosauromorpha. Benton’s cladogram lacks an outgroup or set of outgroups. See the LRT and figures 3-4 for comparison.

When Benton 2014 used suprageneric taxa
and omitted pertinent taxa (Figs. 2–4), he missed the opportunity to show similar sister taxa. Similar sister taxa create the evidence for evolution, taxonomy and systematics. Ironically for a professor with his credentials Benton 2014 too often leads readers astray (Fig. 1) and down blind alleys due to taxon exclusion.

Mesosaurs nest with millerettids in Benton’s cladogram
(Fig. 1) because he copied decades-old traditions without question. Likewise there are no taxa between piscivorous aquatic mesosaurs and herbivorous terrestrial captorhinids in Benton’s cladogram. That’s not good. Mesosaurs don’t look like those clades either overall or in subtle detais. Worse yet, Benton was citing the primary literature going back decades. So these problems are endemic. They are the status quo. They are the current paradigm.

Correcting problems by simply adding taxa is easy
In the LRT mesosaurs nest with similar aquatic piscivores in the resurrected clade Enaliosauria, between pachypleurosaurs and thalattosaurs, far from the base of the Reptilia. That is how the LRT invalidates the traditional clade Parareptilia: by simply adding taxa that attract taxa that don’t belong with other taxa. This is something anyone can do because this is science and creating a cladogram is the method of this science.

Figure 1. Basal amniotes to scale colorized according to the time strata in which their fossils were found. Visean, yellow; Namurian, pink; Westphalian, blue; Permain, tan.
Figure 2. Basal amniotes to scale colorized according to the time strata in which their fossils were found. Visean, yellow; Namurian, pink; Westphalian, blue; Permain, tan. Only few of these taxa are in Benton’s cladogram. None of the amphibian-like amniotes made it in.

Where are the diadectomorphs in Benton’s cladogram (Fig. 1)?
Going with the flow and status quo, Benton considered diadectomorphs to be anamniotes (= not amniotes). This notion became out-dated and invalidated by adding taxa (Fig. 3) several years ago. Diadectes and kin are descendants of millerettids in the LRT. Problem solved. Other traditional diadectomorphs, like Limnoscelis, nest between captorhinids and millerettids in the LRT (Fig. 3). Problem solved by adding taxa. It’s that simple.

There IS such a thing as an amphibian-like reptile.
In the LRT there are many amphibian-like reptiles (Fig. 2). Remember, it’s not the traits that determine relationships, it’s the last common ancestor.

Oddly, Benton 2014 includes Procolophonidae
in his incomplete and misleading cladogram of basal amniotes (Fig. 1). In the LRT (subset Fig. 3) procolophonids are small descendants of larger Diadectes. Just add taxa.

Figure 3. Subset of the LRT focusing on basal reptiles in the clade Lepidosauromorpha. Here the clade Caseasauria nests apart from the Synapsida (Fig. 4) when taxon exclusion is minimized. See figure 4 for the base of the clade Archosauromorpha (cyan).

The LRT basal split between Archosauromorpha and Lepidosauromorpha
has been online for a decade. It’s time to add taxa to other cladograms and leave old hypotheses in the dust before these invalid relationships become further encrusted in our textbooks. Unfortunately, there is a system at the university level that rewards those who stay within the status quo and shuns those who offer more parsimonious alternatives after testing.

The rewards of discovery
are available only to those who break out of the status quo. That’s the wonderful irony of this situation, as it always has been. They say, “The first ones through the gates are the ones who get bloodied the most by the defenders of the castle.” So be brave.

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.
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.

We have a duty to students
to do the work, criticize and eliminate untenable results and finally show them how vertebrate evolution works in all its splendor down to the smallest details and least interesting taxa. The LRT demonstrates that all the puzzle pieces fit when taxa are added. Unfortunately Benton’s textbook leaves us with untenable hypotheses of interrelationships and no sense of interrelationships within and between clades. Unfortunately, this is a widely circulated textbook that students use… and some of these students will someday become professors. That’s how this circle remains unbroken.

Professors should be leading the way
to greater understanding through wider gamut cladograms. Instead they have stepped aside to let amateurs step in to fill the vacuum. Critical thinking and falsifiable solutions should be coming out of our universities. But how can that happen when textbooks that keep the university going are promoting untenable interrelationships as facts? Should professors stop what they are doing and start over?

Yes.

While waiting for this to happen:
Create your own cladogram and keep adding taxa. Knowledge does not have to come in the form of textbook purchased at the university bookstore. Not anymore.

References
Benton MJ 2014. Vertebrate Paleontology 4th ed. Wiley-Blackwell 480pp.