New turtle clades: destined for revision due to taxon exclusion

Joyce et al. 2021 report,
“Over the last 25 years, researchers, mostly paleontologists, have developed a system of rank-free, phylogenetically defined names for the primary clades of turtles. As these names are not considered established by the PhyloCode, the newly created nomenclatural system that governs the naming of clades, we take the opportunity to convert the vast majority of previously defined clade names for extinct and extant turtles into this new nomenclatural framework.”

As long as Joyce et al. are working within a valid phylogenetic context, this sounds like a great idea!

“We are confident that we are establishing names that will remain accepted (valid in the terminology of the ICZN 1999) for years to come.

Well, let’s see if Joyce et al. followed a valid phylogenetic context.

Archelosauria Crawford et al., 2015,
“The smallest crown clade containing the archosaur Crocodylus (orig. Lacerta) niloticus (Laurenti, 1768) and the turtle Testudo graeca Linnaeus, 1758, but not the lepidosaur Lacerta agilis Linnaeus, 1758 (Fig. 1b).”

Not a good start. In the large reptile tree (LRT, 1796+ taxa; subset Fig. 1) the smallest clade that includes Crocodylus and Testudo is a junior synonym for Reptilia (= Amniota). Joyce et al. are not familiar with the basal dichotomy that split reptiles into Lepidosauromorpha (lepidosaurs + turtles) and archosauromorpha (mammals and archosaurs) in the Viséan with Silvanerpeton as the last common ancestor. What can be done when turtle experts don’t agree (see below) on the origin of turtles?

Figure 1. Carbonodraco enters the LRT alongside another recent addition, Kudnu, at the base of the pareiasaurs + turtles.

Figure 1. Carbonodraco enters the LRT alongside another recent addition, Kudnu, at the base of the pareiasaurs + turtles.Figure 1. Carbonodraco enters the LRT alongside another recent addition, Kudnu, at the base of the pareiasaurs + turtles.

Joyce et al. continue:
“Comments—The name Archelosauria was recently introduced by Crawford et al. (2015) for the clade that unites Testudines and Archosauria Cope, 1869b [Gauthier and Padian, 2020] exclusively.” 

That was a mistake due to taxon exclusion. Don’t accept mistakes that put you into an invalid phylogenetic context.

Ankylopoda Lyson et al., 2012,
“Definition—The smallest crown clade containing the lepidosaur Lacerta agilis Linnaeus, 1758 and the turtle Chrysemys (orig. Testudo) picta (Schneider, 1783), but not the archosaur Crocodylus (orig. Lacerta) niloticus (Laurenti, 1768)

In the LRT that clade is the Millerettidae (Watson 1957) with Milleretta as the last common ancestor.

Figure 4. Milleretta, a Late Permian descendant of the Late Pennsylvanian ancestor of turtles and Eunotosaurus.

Figure 2. Milleretta, a Late Permian descendant of the Late Pennsylvanian ancestor of turtles and Eunotosaurus.

Joyce et al. continue:
“Comments—A clade consisting of Testudines and Lepidosauria Haeckel, 1866 [de Queiroz and Gauthier, 2020] to the exclusion of Archosauria has been retrieved in a number of phylogenetic hypotheses (e.g., Rieppel and Reisz 1999; Rieppel 2000; Li et al. 2008), but was only named Ankylopoda relatively recently (Lyson et al. 2012).”

What can be done when turtle experts don’t agree (see above) on the origin of turtles?

Testudinata Klein, 1760
“Definition—“The clade for which a complete turtle shell, as inherited by Testudo graeca Linnaeus, 1758, is an apomorphy. A ‘complete turtle shell’ is herein defined as a composite structure consisting of a carapace with interlocking costals, neurals, peripherals, and a nuchal, together with the plastron comprising interlocking epi-, hyo-, meso- (lost in Testudo graeca), hypo-, xiphiplastra and an entoplastron that are articulated with one another along a bridge” (Joyce et al. 2020b: 1044).

In the LRT (subset Fig. 1) soft-shell turtles (Fig. 3) had a separate parallel origin alongside hard-shell turtles (Fig. 4). Their last common ancestor had no shell: the pareiasaur, Bunostegos (Fig. 4). Workers like Joyce et al. 2021 are working under an assumption that is not true. Turtles are not monophyletic. You can read that manuscript on here. Turtle workers did not let this get published.

Figure 3. Soft shell turtle evolution featuring Arganaceras, Sclerosaurus, Odontochelys and Trionyx.

Figure 3. Soft shell turtle evolution featuring Arganaceras, Sclerosaurus, Odontochelys and Trionyx.

Figure 2. Another gap is filled by nesting E. wuyongae between Bunostegos and Elginia at the base of hard shell turtles in the LRT.

Figure 4. Another gap is filled by nesting E. wuyongae between Bunostegos and Elginia at the base of hard shell turtles in the LRT.

The remainder of Joyce et al. 2021
lists and defines various clades of turtles. Without a clear understanding of parallel turtle origins, even some of these are subject to change when pertinent taxa are included. Most will likely remain the same as they distance themselves from turtle origins.

Joyce et al. (15 co-authors) 2021. A nomenclature for fossil and living turtles using phylogenetically defined clade names. Swiss Journal of Palaeontology 140:5

Huaxiapterus (Sinopterus) benxiensis enters the LPT basal to Tapejaridae

Lü et al. 2007
introduced us to the nearly complete crushed skeleton of Huaxiapterus benxiensis (Figs. 1, 2, BXGM V 0011) in a short paper with a short, three-sentence abstract.

Figure 1. Huaxiapterus benxiensis (BXGM V 0011) in situ, largely complete, crushed and articulated.

Figure 1. Huaxiapterus benxiensis (BXGM V 0011) in situ, largely complete, crushed and articulated.

From the Lü et al. abstract
“A new species of Huaxiapterus: H. benxiensis sp. nov. is erected based on the new specimen. The diagnostic characters of Huaxiapterus benxiensis are well-developed premaxillary crest and parietal spine, the crest and spine parallel and extending posterodorsally, and a shallow groove present on the dorsal surface of the anterior portion of the mandibular symphysis. The different skull morphologies of Chinese tapejarid pterosaurs indicate that they are much more diverse than the previous thought.”

As in all known specimens of pterosaurs, no two adults are alike. That fact gives us an excellent view of microevolution at work in this and other pterosaur clades.

Unfortunately, other workers refuse to add pertinent largely complete taxa shown in the large pterosaur tree (LPT, 256 taxa), nor have they added valid outgroups with correct scores. So the taxonomy and nomenclature in those smaller studies tends to get confused.

Figure 2. DGS reconstruction from the low resolution in situ image in figure 1. Note the brevity of the distal wing phalanges, the robust hind limbs and the gracile humerus.

Figure 2. DGS reconstruction from the low resolution in situ image in figure 1. Note the brevity of the distal wing phalanges, the robust hind limbs and the gracile humerus.

Huaxiapterus benxiensis (Lü et al. 2007, Early Cretaceous, BXGM V 0011, aka Sinopterus benxiensis) nests as the last common ancestor of the Tapejara clade + the Tupuxuara clade. Recently here, here and here we looked at other specimens assigned to Huaxiapterus that were later switched over to Sinopterus. This one (the BXGM specimen, Figs. 1, 2) is among those. They do nest closer to Sinopterus dongi (the holotype) than to Huaxiapterus jii, (the holotype), but H jii was also switched over to Sinopterus.

Almost flightless?
Different from other related pterosaurs Huaxiapterus benxiensis had shorter distal wing phalanges (m4.2, 4.3 and 4.4), a slender humerus and robust hind limbs. Together these traits suggest a trend to a reduced flight ability. Other, more clearly flightless pterosaurs are documented here, here, here and here.

Figure 4. Tapejaridae in the LPT.

Figure 4. Tapejaridae in the LPT. The BXGM specimen shows in the enlargement. It was about the size of Sinopterus dongi at the genesis of the Tupuxuara clade. 

A poor flyer at the base of the flying Tapejaridae
is possible, given that H. benxiensis is probably not the real last common ancestor, but more likely close to the real last common ancestor. It likely evolved its own way. The small size of H. benxiensis is in keeping with phylogenetic miniaturization at the start of other pterosaur clades and major clades in general.

Lü JC, GAo YB, Xing LD, Li ZX and Ji Q 2007. A New Species of Huaxiapterus (Pterosauria: Tapejaridae) from the Early Cretaceous of Western Liaoning, China. Acta Geol Sinica – English 81: 683-687.

Recalibrating clade origins, part 1

Marjanovic 2019 reports on
the origin of several clades based on the fossil literature and molecules.

From the abstract:
“Molecular divergence dating has the potential to overcome the incompleteness of the fossil record in inferring when cladogenetic events (splits, divergences) happened, but needs to be calibrated by the fossil record.”

Testing has shown molecular testing leads to false positives over deep time. Phylogenetic testing using the large reptile tree (LRT, 1630+ taxa) has also shown the fossil record to be, at this date, more complete than Marjanovic (and, no doubt, others) imagine with no new clades appearing for quite some time and all known clades demonstrating a gradual accumulation of traits in the LRT.

“Ideally but unrealistically, this would require practitioners to be specialists in molecular evolution, in the phylogeny and the fossil record of all sampled taxa, and in the chronostratigraphy of the sites the fossils were found in.”

Ideally, but unrealistically, paleontologists would be better off omitting genomics and focusing on taxon exclusion within phenomics (trait-studies).

“Paleontologists have therefore tried to help by publishing compendia of recommended calibrations, and molecular biologists unfamiliar with the fossil record have made heavy use of such works.”

To their detriment and the deliver of false positives.

“Using a recent example of a large timetree inferred from molecular data, I demonstrate that calibration dates cannot be taken from published compendia without risking strong distortions to the results, because compendia become outdated faster than they are published.”

It is strongly recommended that no one infer anything from molecular data, including Dr. Marjanovic.

“The present work cannot serve as such a compendium either; in the slightly longer term, it can only highlight known and overlooked problems.”

The number one overlooked problem is genomics.

“Future authors will need to solve each of these problems anew through a thorough search of the primary paleobiological and chronostratigraphic literature on each calibration date every time they infer a new timetree; over 40% of the sources I cite were published after mid-2016. Treating all calibrations as soft bounds results in younger nodes than treating all calibrations as hard bounds.”

All calibrations involving genomics are going to have to be validated with last common ancestors recovered from phenomics. So, why not skip a step and just use phenomics?

“The unexpected exception are nodes calibrated with both minimum and maximum ages, further demonstrating the widely underestimated importance of maximum ages in divergence dating.”

Now let’s see what Marjanovic discovered, because his abstract does not give a clue. It’s an introduction, not a boiled-down synthesis. Comparisons with the LRT will be noted. Marjanovic’s cladogram is the first to include as wide a gamut as the LRT while employing only generic taxa. Unfortunately no fossil taxa are included. Only ten mammals and six birds are included.

Distinct from the LRT, the Marjanovic cladogram
nests turtles with archosaurs (creating the invalid clade, Archelosauria).

More tomorrow…

Marjanovic D 2019. Recalibrating the transcriptomic timetree of jawed vertebrates.
bioRxiv 2019.12.19.882829 (preprint)

New name and a name resurrection for two Solnhofen pterosaurs

Vidovic and Martill 2017
propose new and resurrect old generic names for two Solnhofen pterosaur specimens. Both are good and needed based on an earlier abstract (Peters 2007) and tree topology published here six years ago at in the large pterosaur tree (LPT, 232 taxa).

Vidovic and Martill remain completely in the dark regarding pterosaur ontogeny. As we learned earlier here, here and here from several adult and juvenile specimens, pterosaurs juveniles and embryos had adult proportions and that’s why they were mechanically able to fly shortly after hatching. Vidovic and Martill report, “It is difficult to distinguish ‘G. rhamphastinus’ (Fig. 3 from the holotype of D. kochi (Fig. 2) other than by using size-related criteria.” And, “juvenile pterosaurs with small crests have been identified.”

Also unfortunately,
Vidovic and Martill still consider pterosaurs to be derived archosaurs or archosauriforms. They report, “A cladistic analysis of the Pterosauria, including all the taxa discussed here, was performed. The analysis included 104 operational taxonomic units (OTUs) comprising 99 pterosaurs and five archosauriforms as an outgroup.” We have to ask ourselves, how long will pterosaur workers remain in the dark on these basic questions that were answered years ago? Look here, here (Peters 2000, 2007) and here.

Pterodactylus wastebasket
Vidovic and Martill write: “Until relatively recently, the genus Pterodactylus Cuvier, 1809 had been a wastebasket taxon that has included many diverse pterosaurs, including some that are now recognized as basal nonpterodactyloids.” We looked at the Pterodactylus wastebasket here in 2011 (Fig. `1).

The Pterodactylus lineage and mislabeled specimens formerly attributed to this "wastebasket" genus

Figure 1. Click to enlarge. The Pterodactylus lineage and mislabeled specimens formerly attributed to this “wastebasket” genus

Wellnhofer 1970
provided catalog numbers for dozens of Solnhofen specimens. Since those numbers are simpler than their museum numbers that’s how they are named (Figs. 2, 3) at

basal germanodactylids

Figure 2. Basal Germanodactylia, Three taxa preceding Germanodactylus rhamphastinus: No. 6, No. 12 and No. 23, the last renamed Diopecephalus kochi. These are all adults.

No. 23 — BSP AS XIX 3 — Diopecephalus kochi (formerly Pterodactylus kochi).
(Fig. 1, left). Seeley had it right originally. Vidovic and Martill correct a century of error when they report, “The holotype of ‘P. kochi’ was considered to belong to a distinct genus by Seeley (1871), which he  unambiguously named Diopecephalus Seeley, 1871.”

No. 64 — B St AS I 745  —
Altmuehlopterus (formerly Germanodactylus) rhamphastinus

Vidovic and Martill reported, “Many phylogenetic studies demonstrate that the two species of Germanodactylus nest together (Kellner 2003; Unwin 2003; Andres & Ji 2008; Lu et al. 2009; Wang et al. 2009; Andres et al. 2014) in a monophyletic clade, but a more focussed analysis by Maisch et al. (2004) demonstrates the genus to be paraphyletic. Maisch et al. (2004) created the nomen nudum Daitingopterus, intended for the reception of ‘G. rhamphastinus’ by placing the name in a table with no specific reference to a specimen.”

Figure 3. Germanodactylus rhamphastinus, No. 64 in the Wellnhofer 1970 catalog.

Figure 3. Germanodactylus rhamphastinus, No. 64 in the Wellnhofer 1970 catalog. Vidovic and Martill renamed this specimen Altmuehlopterus, which is fine and appropriate.

The LPT separates A. (G.) rhamphastinus from G. cristatus by two taxa.

Problems with the Vidovic and Martill 2017 tree:

  1. Lagerpeton nests with Marasuchus, both as proximal outgroups to the Pterosauria. Totally bogus. Tested, validated, real outgroups are listed here. The Fenestrasauria (Peters 2000) is overlooked in the text and references.
  2. Preondactylus and Austriadactylus nest as basalmost pterosaurs. Bergamodactylus, the basalmost pterosaur in the LPT, is excluded.
  3. Only one specimen each of Dorygnathus and Scaphognathus are employed. The LPT shows two clades of pterodactyloid-grade pterosaurs arise from various specimens of Dorygnathus while two others arise from tiny Scaphognathus specimens experiencing phylogenetic miniaturization.
  4. As a result (perhaps) toothy ornithocheirids nest with toothless pteranodontids. In the LPT ornithocheirids arise from equally tooth cycnorhyamphids while shartp-face pteranodontids arise from similar germanodactylids.
  5. The Darwinopterus clade nests as the proximal outgroup to the traditional Pterodactyloidea, when the LPT shows it to be a sterile clade with some pterodactyloid-grade traits.
  6. Altmuehlopterus (formerly Germanodactylus) rhamphastinus nests with G. cristatus
  7. Diopecephalus kochi nests with Pterodactylus antiquus.
  8. Those are the big problems. There are more, but I want to keep it pertinent.

Vidovic and Martill provide clues to their observational problems
when they note, “The genera Pterodactylus and Diopecephalus are remarkably similar.” No they aren’t! Species within the Pterodactylus clade are not even that similar!

Re: Germanodactylus and Pterodactylus,
Vidovic and Martill write: “We agree that some of the differences could be ontogenetically variable and perhaps vary between sexes, so in 1996 it seemed possible that the two species could be at least congeneric.” They disagree with the “common opinion” that the two are distinct genera. Let’s go with the evidence of a large gamut phylogenetic analysis — not opinion — or any analysis lacking so many pertinent taxa.

Vidovic and Martill 2017 rename G. rhamphastinus
Altmuehlopterus rhamphastinus. That’s good. It is generically distinct from its proximal relatives in the LPT. They report, “This name is presented as an alternative to the geographically significant name Daitingopterus (Maisch et al., 2004) which is a nomen nudum.” Not sure how all that falls. I’ll leave such issues to the PhDs.

If you like long nomenclature puzzles
you’ll like Vidovic and Martill 2017. They do a good job of running down all the names that prior workers gave to these century-old specimens. Beware that they are clueless as to the origin of pterosaurs, the ontogeny of pterosaurs and previous work on the phylogeny of pterosaurs based on a much larger taxon list of ingroup and outgroup taxa.

Peters D 2000. A redescription of four prolacertiform genera and implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 293-336
Peters D 2007  The origin and radiation of the Pterosauria. Flugsaurier. The Wellnhofer Pterosaur Meeting, Munich 27. Abstract online here.
Vidovic SU and Martill DM 2017. The taxonomy and phylogeny of Diopecephalus kochi (Wagner, 1837) and ‘Germanodactylus rhamphastinus’ (Wagner, 1851). From: Hone DWE., Witton MP and Martill DM (eds) New Perspectives on Pterosaur Palaeobiology. Geological Society, London, Special Publications, 455,
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.


Same or Different? When Should You Invent a new Genus? or Just Add a Species? Or Revise the Whole Clade?

Now that new pterosaurs are being added to the large pterosaur tree on a fairly constant basis, it’s time to figure out what to name them.

In the old days everything was named “Pterodactylus,” no matter what it was. Sharp-eyed observers soon figured out that there were differences that set certain specimens apart and these were then renamed. Others have not yet been widely recognized as distinct, but they need to be (Fig. 1).

The Pterodactylus lineage and mislabeled specimens formerly attributed to this "wastebasket" genus

Figure 1. Click to enlarge. The Pterodactylus lineage and mislabeled specimens formerly attributed to this “wastebasket” genus

Nowadays, new pterosaurs distinct from all others are being given new generic names, and that’s a good thing. However some of the new specimens nest within long lists of other genera. Others are given new species names within certain genera without nesting near those genera. The problem is a result of the incompleteness of all previously published pterosaur trees. They simply do not include enough taxa. They have a priori deleted all tiny specimens and all congeneric variations that, in the large pterosaur tree, provide clues to the evolution of more derived variations, some of which are distinct genera, as in the Campylognathoides/Rhamphorhynchus transition.

Some examples
MPUM6009 was considered a Eudimorphodon and a Carniadactylus despite nesting far from both genera. MCSNB 8950 was considered a Eudimorphodon, but nested with anurognathids.

Nesodactylus nested within the genus Campylognathoides. Bellubrunnus and Qinglongopterus nested within the genus Rhamphorhynchus.

Fenghuangopterus, Sericipterus and Cacibupteryx nested within the genus Dorygnathus.

Eosipterus and Cuspicephalus nest within the genus Germanodactylus.

Kellner (2010) renamed one Pteranodon, Dawndraco, but it remains surrounded by other Pteranodon specimens.

The question is, do we revise all the old genera and give them new names now that we know how distant some were from each other? Or do we retain those genera and take away the new generic names of the new specimens between them to reflect their traditional generic nesting?

Now all this doesn’t take into account marginal generic names, like Ningchengopterus at the base of the Pterodactylus clade or Muzquizopteryx at the base of the Nyctosaurus clade. These names are likely to be valid because they are distinct genera, but so are many of the species within Pterodactylus and Nyctosaurus. If they were modern birds, not prehistoric pterosaurs, their differences would be recognized.

Part of the historical problem, of course, goes back to Chris Bennett and others who considered smaller species to be immature forms of larger species without adequately describing them or placing them in analysis. It turns out that the vast majority of those where simply smaller forms that were evolving to become the larger forms – or vice versa.

It’s a problem. It needs to be recognized and dealt with. But it will only be recognized if pterosaur specimens are not a priori deleted from analysis for whatever reason.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

Kellner AWA 2010. Comments on the Pteranodontidae (Pterosauria, Pterodactyloidea) with the description of two new species. Anais da Academia Brasileira de Ciências 82(4): 1063-1084.

Nomenclature revisions (part 4)

Today’s blog will tag on the heels of “Nomenclature revisions (parts 1, 2 and 3) to highlight a number of putative clades that are in need of revision, are no longer valid or are redundant in light of the new reptile tree (which is larger than any prior attempt and encompasses all the major clades). Today we’ll restrict our scope to the Ornithosuchia.

Ornithosuchia – retained with a revision
Gauthier (1986) defined Ornithosuchia as the taxon that included extant birds and all extinct archosaurs that are closer to birds than they are to crocodiles. This definition is retained, with a revision. Gauthier’s Ornithosuchia included Ornithosuchidae + Ornithodira. Since pterosaurs were included within Ornithodira, Gauthier’s Ornithosuchia is redundant with Reptilia. Given a new node-based definition that deletes Ornithosuchidae and Pterosauria, the new Ornithosuchia is proposed to include TurfanosuchusTriceratops, their last common ancestor and all of its descendants. The outgroup is Crocodylomorpha.

Ornithodira – redundant
Gauthier (1986) defined “Ornithodira” as all forms closer to birds than to crocodiles. Here this definition is redundant with Ornithosuchia.

Sereno (1991) defined “Ornithodira” as the last common ancestor of the dinosaurs and the pterosaurs, and all its descendants. Here this definition is redundant with Reptilia.

Avesuchia – paraphyletic and redundant
Benton (1999) defined “Avesuchia/crown-group Archosauria” as the taxon comprising “Avemetatarsalia” and “Crurotarsi” (and sister taxa of “Crurotarsi” that are closer to Crocodylia than to Aves), and all their descendants. Because the definition included parasuchians, pterosaurs and Lagerpeton, here this created a paraphyletic clade redundant with Reptilia.

Avemetatarsalia – paraphyletic and redundant
Benton (1999) defined Avemetatarsalia as all “avesuchians/crown-group archosaurs” closer to Dinosauria than to Crocodylia. That definition is redundant with Ornithosuchia. Avemetatarsalia was meant to include Scleromochlus + pterosaurs + dinosauromorphs, but here that clade is paraphyletic (or redundant with Reptilia).

Dinosauriformes – no utility, paraphyletic
Novas defined Dinosauriformes as the most recent common ancestor of Marasuchus (Lagosuchus), Dinosauria and all descendants. Since Marasuchus is derived within the Theropoda here, that definition is now redundant with Dinosauria.

Benton (2004) redefined Dinosauriformes as Neornithes and all ornithodirans closer to Neornithes than to Lagerpeton. Since “Ornithodira” is now redundant with Reptilia (see above) and Lagerpeton now nests outside Euarchosauriformes, Benton’s definition has no utility.

Dinosauromorpha – no utility, paraphyletic
Sereno (1991) defined the Dinosauromorpha as all “Ornithodira” closer to Neornithes than to Pterosauria. Since the Pterosauria is far removed from the Dinosauria, this definition has no utility.

Sereno (1991) did not fix the problem when he stated the clade consisted of Passer and all species closer to Passer than to Pterodactylus, Ornithosuchus and Crocodylus. Sereno (1991) also provided a node clade definition: the last common ancestor of Lagerpeton, Lagosuchus, Pseudolagosuchus and the Dinosauria (including Aves) and all its descendants. Here Sereno’s definition is redundant with Archosauriformes. Removing the proterochampsid, Lagerpeton, from the definition creates a monophyletic clade, but one that would be redundant with Dinosauriformes (= Dinosauria). At present there are no non-dinosaur members to populate the Dinosauriformes or the Dinosauromorpha, since Crocodylomorpha is now the sister taxon of the Dinosauria.

Dinosauria – retained and expanded
Holtz and Padian (1995) defined the Dinosauria as all descendants of the most recent common ancestor of Triceratops and Passer, the sparrow. Standing firm, this definition still includes all taxa traditionally considered dinosaurs. It also adds members of the Poposauridae, PisanosaurusSilesaurus and Lotosaurus, a clade here labeled the Paraornithischia. Traditional clade names and inclusion lists for Theropoda, Sauropodomorpha and Ornithischia are retained.

Saurischia – no utility, paraphyletic
Seeley (1888) classified dinosaurs into two orders based on pelvis morphology. Here, with the Phytodinosauria, this division is polyphyletic and has lost its usefulness.

Phytodinosauria – resurrected
Bakker (1986) coined the term “Phytodinosauria” for a clade including Sauropodomorpha + Ornithischia. Here testing supports this clade.

Paraornithischia – new clade
The new clade Paraornithischia is proposed to include EffigiaLotosaurus, their last common ancestor and all of its descendants. This clade of apparent herbivores (none have sharp, serrated teeth and some are toothless) demonstrates a variety that hints at a wider radiation of undiscovered forms, all currently restricted to the Middle and Late Triassic. The clade also includes PisanosaurusShuvosaurus/Chatterjeea and Silesaurus. This clade consists only of herbivores, many of which had a predentary, paired predentaries or something like it that may have been fused to the often toothless dentaries.  While it may be tempting to consider this the clade basal to Ornithischia, at present moving this branch to the base of the Ornithischia adds four steps. More taxa will bring greater resolution.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

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