Friday, April 19, 2013

Are Daemonosaurus, silesaurids and poposaurs phytodinosaurs? plus conclusion on Peters

No, of course not.  Phytodinosauria doesn't even exist.   But Peters doesn't believe that, due to the many issues discovered in my evaluation of his analysis.  Last time we looked at the characters he uses to support his heterodox Theropoda.  This time we'll look at the characters he uses to support his heterodox Phytodinosauria and internal clades.  A spoiler for those who don't want to read further- none of Peters' clades are even plausible except for ornithischian Daemonosaurus, which is rejected by "only" 7-10 more steps compared to 25-76 more steps for his other clades.

Phytodinosauria (Panphagia, Pampadromaeus, Sauropodomorpha, Daemonosaurus, Ornithischia, Silesauridae, Poposauridae)
8. Posterior maxilla not flared laterally to form constricted snout.  This was coded by Peters for way too many taxa, and actually has a very mixed distribution.  Effigia, Coelophysis (miscoded), Pantydraco and Heterodontosaurus (not coded) lack it, while Lotosaurus (miscoded), Herrerasaurus, possibly Pisanosaurus (not coded) and Lesothosaurus (miscoded) have it.  Daemonosaurus cannot be coded, contra Peters.
22. External naris faces dorsolaterally instead of laterally.  Peters again codes this for many more taxa than can be evaluated, and miscodes Heterodontosaurus and Silesaurus as dorsolateral when they are actually lateral.  In Peters' topology it's still recovered as supporting this clade, but barely.  Daemonosaurus cannot be coded, contra Peters.
45. Frontal without posterior process.  This was an example in my list of characters misunderstood by Peters.  No included taxon has such a process.
69. Squamosal and quadratojugal form a semicircular indentation in the infratemporal fenestra.  Peters codes this as present in Pampadromaeus (actually lacks it), Lotosaurus, Silesaurus (actually unknown) and Shuvosaurus (lacks it).  That already disqualifies it, but I'll also note that the not included Plateosaurus and Massospondylus carinatus can have a semicircular or pointed indentation, so it's quite a variable character.  Again Daemonosaurus cannot be coded, contra Peters.
119. Dentary decurved.  This is miscoded in Panphagia, Massospondylus kaalae and Daemonosaurus, and not coded in Saturnalia (actually absent).  So only Pampadromaeus and Pantydraco are correctly coded as having it, and I have no issue with this being a synapomorphy within Sauropodomorpha.
125. Posterior mandible deepest anteriorly.  This was miscoded as present in Pampadromaeus, Panphagia, Shuvosaurus (actually unknown) and Effigia.  So it would actually diagnose the sauropodomorph+ornithischian node in Peters tree, though its absence in the non-included Efraasia makes its convergent development in each group likely.  Again, this is miscoded in Daemonosaurus.
Results-  Of six characters, Daemonosaurus has one (which is found in all examined taxa) and lacks two.  Only the external naris being angled more dorsally even potentially supports the clade.

(Sauropodomorpha, Daemonosaurus, Ornithischia, Silesauridae, Poposauridae)
6. Premaxilla a third or more of preorbital length.  This is miscoded in Pantydraco and Silesaurus.  It actually distinguishes ornithischians and poposaurids, while also being present in Massospondylus kaalae (but not the non-included M. carinatus, Plateosaurus or Efraasia).  Yet again, it is miscoded in Daemonosaurus.
11. Nasals widest at midpoint.  This is also true in Panphagia (uncoded) and Pampadromaeus (miscoded).  This would leave it as a phytodinosaur character, except that Turfanosuchus (miscoded) has it has well, and among 'paraornithischians' only Effigia has it (Silesaurus, Shuvosaurus and Lotosaurus miscoded).  Daemonosaurus is correctly coded as having it.
37. Orbit enters anterior half of skull.  Within 'paraornithischians' this is only true in Lotosaurus, not Silesaurus (unknown, miscoded), Shuvosaurus (unknown, miscoded) or Effigia (miscoded).  Otherwise it would fit combining derived sauropodomorphs with ornithischians.  Though note Daemonosaurus lacks it and is again miscoded.
95. Interpterygoid vacuity tapers sharply anteriorly.  This was coded as absent in Turfanosuchus (present), Gracilisuchus and Herrerasaurus (unknown).   In reality, all examined taxa except Gracilisuchus have it or could have it.
113. Caniniform teeth absent in maxilla.  This is here mostly due to misunderstandings on Peters' part.  He codes the toothless scorable poposaurs as having it, but as they lack teeth of any sort, they should be coded inapplicable for whether those teeth are caniniform.  More importantly, the character is used by authors Peters' cites for it such as deBraga and Rieppel (1997- ch. 95) in the sense that a taxon has caniform teeth when their size is greatest near the middle of the maxillary tooth tow (as opposed to anteriorly, or all being equally large).  So we can code taxa for this character even when they lack elongate pointed teeth that are usually thought of as caniniform.  When we do so, we see that Silesaurus and Massospondylus kaalae truly do lack caniniform teeth, but that Pantydraco doesn't preserve the anterior maxilla and that ornithischians have teeth near the middle largest so actually have a caniniform region.  Expanding to taxa not included by Peters, Sacisaurus still has a caniniform region, as does Efraasia, while Plateosaurus is debatable (first tooth slightly smaller).  So it seems that Silesaurus and plateosaurs evolved this convergently.  Peters correctly codes Daemonosaurus has having caniniform teeth.
115. Lateral teeth blunt.  This is part of a composite character involving sharpness, serration size and crown base constriction.  It's a good example of why such characters are bad, because while Scelidosaurus is coded as blunt (state 1), its teeth are also multicusped with a constricted base (state 3).  In any case, we'll look past the technical errors here and check the distribution of teeth with large serrations and constricted bases, which is what makes the teeth in question blunt compared to a typical archosauriform tooth.
For serration size, Panphagia and Pampadromeus are miscoded as being different than e.g. Thecodontosaurus and Pantydraco.  Yet Peters leaves Saturnalia uncoded, when it actually has small serrations.  Another thing Peters leaves out is that the fangs of Heterodontosaurus have tiny serrations like carnivorous archosaur teeth, so it has both states.  He correctly codes Silesaurus and Daemonosaurus as lacking it, but leaves Poposaurus uncoded when it lacked it too.  All of this combines so that it is equally parsimonious being a phytodinosaur character or developing convergently in Pampadromaeus+Panphagia, sauropodomorphs, ornithischians and Pisanosaurus in his tree.
The situation is similar for constricted crown bases- Pampadromeus and Panphagia were miscoded as lacking them, Heterodontosaurus actually has both states due to its fangs, Daemonosaurus was correctly coded as lacking it, and Poposaurus lacks it too but was left uncoded.  Though because Saturnalia and Silesaurus both have this character, it's slightly more parsimonious as a phytodinosaur synapomorphy reversed in a few cases.
What complicates the situation are the silesaurids Peters didn't include.  Sacisaurus and Diodorus both have large serrations, but Asilisaurus has small ones like Silesaurus itself.  Sacisaurus and Diodorus also have constricted roots, but Asilisaurus is unique among silesaurids (ignoring Lewisuchus of course) in lacking them.  This leaves both characters changing 6.5 and 4.5 times respectively if they are phytodinosaurian synapomorphies that reversed in some members.  They're much simpler in the standard phylogeny, where they each evolve three times (in derived silesaurids, derived sauropodomorphs and derived ornithischians), and the basal members of each (Asilisaurus, Silesaurus, Saturnalia, heterodontosaurids) show intermediate conditions.
122. Dentary extends into coronoid process.  Back to simple problems.  Peters miscoded Pantydraco (unpreserved), Daemonosaurus, Lotosaurus and Effigia as having this.  He also didn't code Silesaurus and Shuvosaurus for it, but they lack it too.  It's actually only present in ornithischians and some anchisaurs like Massospondylus, but not more basal sauropodomorphs unexamined by Peters like Efraasia and Plateosaurus, or even some taxa closely related to Massospondylus like Adeopapposaurus and Mussaurus.
128. Mandible straight ventrally.  Another complicated character because Peters' divides this into several states, with the anterior and posterior mandible being straight, concave or convex.  It's full of homoplasy in Peters' codings, with Silesaurus+Lotosaurus and ornithischians reversing to the 'straight anterior convex posterior' state he codes Panphagia and Pampadromeus for.  But as with so many of these characters, Peters miscodes a large number of taxa.  Saturnalia, Pantydraco and Massospondylus kaalae actually have concave anterior mandibles, his basalmost ornithischian Scelidosaurus and Pisanosaurus have convex ones, and Lotosaurus' and Shuvosaurus' are concave.  Posteriorly, none of his sauropodomorphs can be coded, Silesaurus' is convex, Lotosaurus and Effigia have both straight and convex margins and his basalmost ornithischians have both straight and convex (Scelidosaurus), concave (Heterodontosaurus) or convex (Agilisaurus) margins.  There's a huge amount of homoplasy and numerous taxa vary simply between individuals or sides of the head.
131. Cervicals decrease in size anteriorly.  Besides the atlas and often the axis, this isn't true in any examined taxon.  Peters simply miscoded them.
137. Mid-cervical centra (here c5-7 are used) shorter than mid dorsal centra (here d7-9 used).  This was miscoded by Peters as true in sauropodomorphs (ironically famous for their long necks).  It's found in Poposaurus, Lotosaurus and ornithischians (for at least some vertebrae), and is more parsimonious even in his tree as being convergent in these groups than being a phytodinosaur character lost in sauropodomorphs, silesaurids and shuvosaurs.
142. Lumbar area ("shortened to missing dorsal ribs") absent.  This is a hard one to code due to preservation and definition.  Very few taxa preserve the posteriormost dorsal ribs, and they're shorter than others as a rule.  It might be easiest just to note that Peters' coded many taxa whose posteriormost ribs are unpreserved and/or present in reconstructions, which accounts for all six non-ornithischians coded as lacking a lumbar area by Peters.  Also Scelidosaurus, Peters' basalmost ornithischian, was described as having a lumbar vertebra by Owen, while Plateosaurus has one or two dorsals without ribs as well.
144. Three to four sacral vertebrae, which if ordered would be "three or more sacral vertebrae".  Herrerasaurus was miscoded as having less, while Pseudolagosuchus was miscoded as unknown, but has two.  This means it now takes 4 steps in Peters' tree, while it would take five for Dinosauria to start with three sacrals and reverse in Marasuchus, Tawa and silesaurid Pseudolagosuchus.  But also note basal silesaurid Asilisaurus only has two, while theropod Eodromaeus has three, as does Eoraptor which wherever it goes seems close to theropods or Panphagia and Pampadromeus.  This leaves it more likely three sacrals are primitive for dinosaurs in Peters' tree, and more likely Silesaurus got its large sacral count convergently in reality.
175. Metacarpal II longest.  This is actually a fine character for grouping Sauropodomorpha and Ornithischia (note the condition in Pampadromaeus and Panphagia aren't known, so it doesn't support them being basal to both; indeed, the similar but unincluded Guaibasaurus also has it).  Of Peters' coded 'paraornithischians' though, Poposaurus has it but Lotosaurus is miscoded as having it (based on a sculpted museum mount I assume).  So strict Phytodinosauria sure, but that plus poposaurs is ambiguous.
195. Tibia shorter than femur.  This also works in Peters' tree, helped by his placement of Scelidosaurus basally in Ornithischia, as others' have long tibiae.   But it takes the same number of steps in the standard tree, where dinosauriforms have long tibiae, and it reverses in Silesaurus, Herrerasaurus, sauropodomorphs and Scelidosaurus (+ eurypods).
199. Tibia less than twice ilial length.  Hey, didn't we just look at tibial length? *cough correlated cough*  But that doesn't even matter here, because this is also true in Pampadromaeus (left uncoded by Peters), Herrerasaurus (miscoded) and possibly Tawa (the schematic reconstruction suggests so, but I would leave it uncoded for now).  So of included taxa, it's only not true in Marasuchus, Silesaurus and Panphagia.  Invalid.
Results- Of fifteen characters, Daemonosaurus has one (nasals widest in middle; which would work for Sauropodomorpha+Ornithischia) and a half (anterior mandible straight ventrally), though the latter doesn't actually support any similar clade.  It lacks five.  Nasals widest at midpoint would support Sauropodomorpha+Ornithischia; orbit enters anterior half of skull would support derived sauropodomorphs plus ornithischians; metacarpal II longest would support either variant; premaxilla a third or more of preorbital length and (somwhat ambiguously) short mid cervical centra would support Poposauridae+Ornithischia.  Large serrations and constricted crown bases would indeed resolve at the previous node (Phytodinosauria) in Peters' tree, but requires less homoplasy in the standard tree.  A short tibia also resolves here, but is equally parsimonious in the standard phylogeny.

'Paraornithischia' (Pisanosaurus, Poposauridae, Silesauridae)
28. Maxilla ventrally straight.  Miscoded in Pisanosaurus (unknown), Silesaurus, Shuvosaurus (unknown) and Effigia, so only Lotosaurus is correctly coded.  Varies so much that either a straight or convex maxilla might be basal for Saurischia, Dinosauria, Silesauridae+Dinosauria or Dinosauriformes.
112. Maxillary teeth shorter than twice their FABL.  Note Peters wrongly codes the toothless poposaurs as having this when they should be inapplicable.  More generally, this true for some teeth in basically every taxon known from a good sample size, including standard carnivorous taxa like theropods.  It's only true for all maxillary teeth in some derived ornithischians.
117. Laterally placed surangular ridge in dorsal view.  This was an example of characters Peters misunderstood and thus coded inaccurately (see part 1 of my critique).  In actuality, all examined taxa have this ridge.
119. Dentary straight.  Pisanosaurus miscoded.  While true in poposaurs and silesaurids, this is also primitive for dinosaurs in general and found in Arizonasaurus.  Peters didn't find this due to miscodings (e.g. Scelidosaurus, Heterodontosaurus, Panphagia) and missing taxa.
167. Olecranon process absent.  Miscoded in Pisanosaurus (unknown), Lotosaurus (unreported), Poposaurus (unreported).  It's only true in Silesaurus, Effigia, Gracilisuchus and some ornithischians (Scutellosaurus and Agilisaurus+Hexinlusaurus).  Thus it fits with the silesaurid+poposaur clade in Peters tree, though in the standard tree the olecranon in basal rauisuchians sensu lato and crocodylomorphs indicate convergence.
178. Four phalanges in manual digit IV (up from three or less).  Miscoded in Pisanosaurus (unknown), Lotosaurus (five phalanges) and Effigia (unknown).  Correctly coded as absent in Poposaurus (three phalanges), and no other 'paraornithischians' can be coded.  This leaves the state untrue for any taxon.
205. (Preseumedly large) calcaneal tuber proximally oriented.  Miscoded in Pisanosaurus (absent) and correctly coded as absent in silesaurids.  Thus it's only present in poposaurs, which in standard trees is because they're outside Avemetatarsalia and doesn't require a reversal then.
Results- Only the absent olecranon would work for this clade in Peters' tree, which is only known in Silesaurus and Effigia.  Note Pisanosaurus was miscoded for all except one which is present in all examined taxa (and coded correctly by accident by Peters as he was looking at the wrong structure), and another which actually varies in almost all taxa (and may vary in Pisanosaurus if anterior maxillary teeth were preserved, as these are the elongate ones in basal ornithischians).  Thus there's no evidence Pisanosaurus is closer to poposaurs and silesaurs than to ornithischians.

84. Postorbital extends posteriorly less than halfway through the parietal.  This was only coded as true in Lotosaurus and Effigia and is miscoded in both anyway.  It's actually not found in any included taxon except Terrestrisuchus.
115. Maxilla toothless.  Poposaurus was miscoded as unknown when it has maxillary teeth.  Being absent in silesaurids, it's only present in Lotosaurus and shuvosaurs, which I have no issue with and takes less steps in the standard phylogeny than Peters'.
118. Paired predentary.  A fictional element found in no animal I know of. Peters just imagines predentaries are fused to dentaries in these taxa.
135. Cervical ribs of average width and at high angle to neck.  Both width and orientation miscoded in Lotosaurus, Silesaurus and Effigia (unknown).  Only Gracilisuchus, some Lotosaurus ribs and some Hexinlusaurus ribs are not slender, and no examined taxon has high-angled ribs.
140. Cervicals 6-9 without offset central faces.  Miscoded in Silesaurus, and I have no issue with poposaurs having it, since it's generally considered the primitive condition modified in dinosauriforms.
160. Clavicle present (and shorter than scapula, as if that needed to be said).  This is only here because Peters miscoded a ton of taxa as lacking clavicles when they're just incompletely preserved (also note no silesaurid can be coded).  In actuality, only some crocodylomorphs and ornithischians have good evidence for missing clavicles, while saurischians retain them.
181. Manual unguals blunt.  Only known in poposaurs (though Effigia was miscoded).
Results- Not a single character is even present in silesaurids.  Perhaps the biggest fail of any Peters clade examined here.

14. Premaxilla-maxilla notch over 45 degrees.  This entire character is miscoded by Peters.  In actuality, all examined taxa lack a notch except Tawa+Coelophysis, Pampadromaeus and heterodontosaurids (with Eoraptor and Daemonosaurus being intermediate).
15. Premaxilla ventral surface angled anteroventrally.  This is untrue in silesaurids and, contra Peters, present in Effigia and probably Poposaurus.
31. Orbit shorter than postorbital skull length.  This is unknown in silesaurids.
44. Frontal not wider posteriorly than anteriorly.  This is widely miscoded by Peters and actually only present in Gracilisuchus among examined taxa.
125. Posterior mandible of even depth anteriorly and posteriorly.  Intrue, both Silesaurus and Lotosaurus have mandibles deepest in the middle, which is true for most taxa.
128. Ventral mandible edge straight anteriorly and convex posteriorly (as opposed to completely straight).  Lotosaurus actually has a concave anterior mandible, with a (sometimes) convex posterior mandible is typical of all but some herbivorous dinosaurs and is also found in some specimens of the only other scorable poposaur, Effigia.
145. Sacral neural spines taller than acetabulum.  True in Lotosaurus and Silesaurus, but unknown in Pseudolagosuchus (unknown), and absent in the unexamined silesaurid Asilisaurus.  This makes the character ambiguous. 
149. Gastralia absent.  Peters miscoded Silesaurus (absent), Pseudolagosuchus (unknown) and Lotosaurus (unknown).  Another instance of Peters assuming partially preserved skeletons or mounted specimens include all originally present elements.
170. Forelimb between 55 and 100 percent of hindlimb length (instead of being shorter).   The ratio in Lotosaurus is unreported and was guessed at by Peters from mounts of uncertain completeness.
183. Preacetabular process truncated.  The condition in Lotosaurus is unreported and was guessed at by Peters from mounts of uncertain completeness.
200. Iliofibularis tubercle a 'spot'.   Silesaurus, Pseudolagosuchus and Lotosaurus all actually have a crest-like tubercle, so are miscoded.
210. Metatarsus less than half of tibial length.  Miscoded in Silesaurus, Poposaurus and Effigia, so only untrue in Effigia among these taxa. 
Results- Only the long sacral neural spines even ambiguously link Silesaurus and Lotosaurus.  The rest of the characters are highly miscoded.

(Sauropodomorpha, Daemonosaurus, Ornithischia)
33. Naris larger than antorbital fenestra.  This was miscoded for Daemonosaurus, Saturnalia (unknown) and Pantydraco.  It's actually only present in ornithischians and some plateosaurs, as even taxa like the unincluded Riojasaurus, Sellosaurus, Lufengosaurus and Jingshanosaurus lack it.
41. Frontoparietal suture straight and longer than frontonasal suture.  Another composite character, the length aspect of which is true for basically all examined taxa.  Straightness does indeed work as a character for this clade though.
69. Squamosal and quadratojugal do not contact.  This is only here because Peters miscoded theropods as having contact and sauropodomorphs, Heterodontosaurus and Lesothosaurus as lacking contact.  It's actually only true in theropods and some ornithischians (Scelidosaurus, Agilisaurus+Hexinlusaurus).  Miscoded in Daemonosaurus as it is actually not known.
127. Retroarticular process angles ventrally.  Widely miscoded and only actually present in Hexinlusaurus among included taxa.
179. Manual digit IV reduced in width.  This is true in almost all dinosaurs and was actually miscoded by Peters as absent in Pisanosaurus (actually unknown), Poposaurus and Effigia.  So in his tree it would actually diagnose Dinosauria and reverse in Lotosaurus and (miscoded) Lesothosaurus.  Note it is equally parsimonious for it to converge in derived poposaurids and dinosaurs as in the standard phylogeny.
191.  Acetabulum at least partly perforated.  Similar to the previous character, this is true in all dinosaurs and was miscoded by Peters as being absent in the examined poposaurs.  It was also miscoded as lacking in Pampadromaeus and Panphagia, and may even be present in Silesaurus (though lacking in the unincluded Asilisaurus and probably Sacisaurus). 
216. Phalanges of pedal digit IV subequal to metatarsal IV.  Here's an example of how not ordering your characters can lead to problems.  In Peters' data, the outgroup and 'paraornithischians' have long phalanges, sauropodomorphs and ornithischians have subequal phalanges and theropods have short phalanges.  PAUP doesn't realize which of these are most similar, but if it were ordered PAUP would know this means theropods are most like sauropodomorphs and ornithischians.  In any case, Peters miscoded Herrerasaurus which has subequal phalanges too, and Saturnalia, Lesothosaurus and Hexinlusaurus (left uncoded) which all have shorter phalanges.  The latter examples, along with Pisanosaurus and unexamined Tianyulong having short phalanges, means this is probably the basal state for ornithischians and sauropodomorphs.  Yes Peters has Scelidosaurus basal in Ornithischia, but also miscoded it as subequal when it actually has long phalanges, so doesn't fit with subequal being basal for sauropodomorphs+ornithischians anyway.  As theropods are subequal (Herrerasaurus, Dilophosaurus) or short (Coelophysis, Liliensternus, Procompsognathus), this leaves it ambiguous whether short phalanges are a phytodinosaurian character.
Results- Daemonosaurus has one of these (straight frontoparietal suture), which is indeed valid for this clade.  It lacks two, neither of which really diagnoses the clade anyway.  Besides the straight frontoparietal suture, only the short pedal digit IV phalanges even ambiguously works for this clade.

(Daemonosaurus, Ornithischia)
114. Last maxillary tooth placed at mid orbit (instead of anterior orbit).  This works, though note it's also present in Eoraptor, wherever that taxon goes (Peters seems to think Theropoda).
Results- Yes, this single character is valid for this clade.

Total Results- There are several heterodox aspects that should be evaluated.

First is that 'paraornithischians' are closer to phytodinosaurs than to theropods.  This is supported by external naris being angled more dorsally, which takes one more step in the standard phylogeny.  A short tibia takes equal steps, and while large serrations and constricted crown bases work for this node in Peters' tree, they are better explained by the standard tree.  Even if we just correct Peters' characters, this grouping takes 12 more steps in his trees.  When I added new characters and taxa, it took 34 more steps.  In Nesbitt's analysis with far more anatomical data (even excluding taxa Peters doesn't see as avemetatarsalians, like pterosaurs and lagerpetonids), it takes an astounding 76 more steps.  Utterly rejected.

Regarding Paraornithischia itself, no characters support placing Pisanosaurus in it, and this is 13 (Peters' characters corrected), 26 (Peters' corrected matrix with more data added) and 50 (Nesbitt's reduced matrix) steps longer than the most parsimonious tree.  Pisanosaurus being a paraornithischian is very strongly rejected.

For a more reduced Paraornithischia containing only silesaurids and poposaurs, only two characters could  plausibly support this in Peters' matrix.  Silesaurus could share an absent olecranon with poposaurs (only known in Effigia), then ambigiously share long sacral neural spines with Lotosaurus (unknown in Poposaurus and Arizonosaurus, though probable in both considering other neural spines; absent in shuvosaurs).  This is incredibly weak support compared to the numerous characters placing Silesaurus close to dinosaurs and poposaurs in Pseudosuchia.  Enforcing poposaurs and silesaurids as a monophyletic group takes 8 more steps in Peters' matrix both with corrected codings and once the extra characters and taxa are added (in both cases they are sister to Dinosauria and Pisanosaurus is ornithischian), and 41 more steps in Nesbitt's reduced matrix (where they are sister to Dinosauriformes and Pisanosaurus again is ornithischian).  So strongly rejected again, though at least leaving Pisanosaurus out made it a tad less homoplasious.

Peters places Lotosaurus closer to silesaurids than to poposaurs.  Given the liklihood Poposaurus has tall sacral neural spines noted above, even this one remaining possibly applicable character is questionable.  This grouping takes 15 more steps using Peters' matrix with corrected codings, where the Lotosaurus+silesaurid clade ends up in Crocodylomorpha.  It takes 19 more steps once the extra characters and taxa are added, where the clade falls out between Crocodylotarsi and poposaurs on the grade leading to dinosauriforms.  No other silesaurids follow.  Finally, it takes 45 more steps in Nesbitt's reduced matrix, where it's apparently easiest just to let Lotosaurus be placed as the basalmost silesaurid.  Another strongly rejected concept, which when taken together with the previous two paragraphs shows all parts of 'Paraornithischia' besides Silesauridae and Poposauridae each being real is unlikely in the extreme.

Back to actual dinosaurs, there is Peters' idea derived sauropodomorphs are closer to ornithischians than to Panphagia and Pampadromeus.  This is supported by orbit enters anterior half of skull, a straight frontoparietal suture, (ambiguously) posterior mandible deepest anteriorly and (ambiguously) tibia shorter than femur, which are outweighed by the sauropodomorph characters not included by Peters.  Just fixing Peters' characters leaves this 5 steps less likely than sauropodomorph monophyly, and adding taxa and characters brings it to 11 steps less likely.  But if you try this in a dedicated sauropodomorph matrix like Cabreira et al. (2011), it's a whopping 25 steps less parsimonious.  Very unlikely to be true.

Then there's Sauropodomorpha+Ornithischia itself.  This has actually been suggested by other workers before, unlike most of Peters' unusual ideas (technically, Peters doesn't support the standard version since Pisanosaurus, Pampadromaeus and Panphagia are excluded, and Daemonosaurus is included).  This is supported by nasals widest at midlength, (ambiguously due to Saturnalia) enlarged serrations, teeth constricted at base, metacarpal II longest and (ambiguously) short phalanges of pedal digit IV.  But these are outweighed even in his own matrix, where correcting codings makes it 2 steps less parsimonious.  Adding characters and taxa brings this up to 8 steps.  In Nesbitt's matrix (again only using taxa Peters did in this part of his tree), it takes 13 more steps.  So this non-Petersian Phytodinosauria isn't completely rejected, but does seem quite unlikely.

Finally, there's the idea Daemonosaurus is a member of any of the above clades instead of being a theropod.  Of all of the above valid characters, it only has nasals widest at midpoint (sauropodomorphs+ornithischians), straight frontoparietal suture (derived sauropodomorphs+ornithischians) and last maxillary tooth placed at mid orbit (ornithischians).  But it lacks large serrations, constricted tooth crown bases, orbit enters anterior half of skull, and posterior mandible deepest anteriorly, and the above clades are probably not real anyway.  We saw before forcing Daemonosaurus to be ornithischian took 7-10 more steps depending on the matrix used.  Forcing it to be phytodinosaurian takes 2 (sister to remaining phytodinosaurs), 10 (it's sister to Eodromaeus with both sister to other phytodinosaurs, and theropods are paraphyletic to the latter) or 20 (herrerasaurids become basalmost phytodinosaurs, followed by Daemonosaurus+Eoraptor) more steps in Peters' corrected, Peters' corrected with added data, and Sues et al.'s reduced analyses respectively.  So far from helping Phytodinosauria, placing Daemonosaurus in that clade makes it 0, 2 or 4 steps less likely to exist.  The most you can say for Peters' idea is that in the quite unlikely chance Phytodinosauria is real, making Daemonosaurus the basalmost member is only slightly more problematic, though taxa he considers theropods such as herrerasaurids, Eoraptor and/or Eodromaeus would follow.

As Daemonosaurus is so emphasized by Peters, which characters suggest it is a theropod instead of an ornithischian?  We previously saw it took ten more steps to place Daemonosaurus in Ornithischia in the full matrix used here, and seven more in Sues et al.'s (2011) original matrix.  Some of the characters suggested by Sues et al. have more homoplasy when examined in the larger matrix, but several have relatively clear distributions.  Remember despite the homoplasy noted below, these were still found to diagnose the clades when all of Peters' characters were included too.  Characters that could also work for an ornithischian placement aren't noted.

- Ventral ramus of the opisthotic not covered by the lateralmost edge of exoccipital in posterior view. Reverses in Massospondylus kaalae and avepods.  Not used by Peters.

- Maxilla ventrally convex.  Exactly which node this belongs to is uncertain as Eoraptor and Pampadromaeus have it, but other sauropodomorphs don't.  Tawa is miscoded by Peters.

- Snout roughly triangular. As in Tawa and Coelophysis, which are more derived than Eoraptor, Herrerasaurus and Eodromaeus in this tree.  Miscoded in Daemonosaurus by Peters.
- Sharp jugal ridge. In all examined theropods including Eoraptor, also in some Scelidosaurus specimens.  Not used by Peters.
- Deep pneumatic fossae in cervical centra. Also in sauropods.  Not used by Peters.

Sister to Tawa
- Less than four premaxillary teeth.  Also in heterodontosaurids, but as they're not sister to Daemonosaurus or even basal in Ornithischia in Peters' trees, this doesn't matter.  Miscoded in Daemonosaurus and Tawa by Peters.
- Jugal, anterior extent of the slot for the quadratojugal: at or anterior to the posterior edge of the dorsal process of the jugal.  Also in Pampadromaeus, some Scelidosaurus and Massospondylus carinatus specimens.  Not used by Peters.
- Exoccipital, lateral surface: without subvertical crest (metotic strut). Unique among dinosauriforms.  Not used by Peters.

"You have your assignment: Nest Daemonosaurus with theropods while including Heterodontosaurus and Massospondylus. That’s a half-dozen to a dozen taxa at most to deal with. Then we’ll compare answers."

Assignment complete, Peters.  Comparison indicates massive miscoding by you, a lack of included taxa and characters, and in this particular case using a largely fictional skull for Daemonosaurus.  Almost like what I figured out by just looking at a portion of your dataset without reanalyzing the entire thing...

And that wraps things up as far as Peters' Dinosauria goes.  Unfortunately, despite my utter demolishing of his analysis, he's unlikely to fix it.  So many of the problems are due to a third of the characters being miscoded, but while he seems willing to fix a few, for most he remains stubbornly convinced that his tracing is better than what's indicated by the actual experts who saw and studied the material.  Sure you can tell Peters where he gets things wrong, but he'll consider that worthless.  Sometimes he requests you take the time to trace your interpretation for him, but his errors are so numerous and his understanding of anatomy so poor that it would be a full time job for anyone to educate him.  He also remains intransigent regarding how he should fix his character formulation and ordering.  Just doesn't care.  Similarly, Peters is blase about his potential for miscoding by using reconstructions and sculpted mounts.  It will balance out he says, because his terribly miscoded analysis has falsely assured him that most nodes are strongly supported, making noise unimportant.  He's unconcerned with adding more characters because he just wants to see what his 228 will find, apparently not realizing limiting it to such a small amount makes the result almost worthless.  It's like my coding new taxa into small older analyses on the Database- it's fun and interesting to see how taxa fall out using classic data, but I would never claim e.g. segnosaurs are closer to caenagnathids than to oviraptorids just because that's where they ended up when added to Gauthier's 1986 matrix.  Even if his whole topology is shown to be based on erroneous data, he'll get things backwards and compare the resulting trees to see how subjectively similar related taxa seem to him.  As if the result matters when the data used to get it are wrong.  So what point is there in trying to educate someone who refuses to learn?  While I was naive in thinking a detailed critique just might show Peters how much more work he needs to do before his analysis is useful, I hope this will at least help those amateurs who think Peters' ideas have merit and fall for his "I'm a rebel underdog whose ideas are disliked by the experts because they're blinded by tradition and conformity" schtick.  All of the information in this series of posts (and more) will be uploaded to the Database in the Evaluating Phylogenetic Analyses section.  Until Peters shows willingness to do more than correct a few scores, it's just a time sink to engage him in detail.  Hope you all enjoyed the series.


  1. Mickey, in your zeal to make sure my coding was filled with mistakes your recoding perverts mine. For instance, in character 112 you have to have mx teeth twice deeper than wide or not. That means all conditions other than twice deeper is “not.” That includes toothlessness. Perhaps if you recode again using this strict yes/no dichotomy you will find a tree that echoes actual evolutionary events.

    1. This is where you don’t understand phylogenetic analyses. By coding both stout teeth and toothlessness as one state, you’re saying toothlessness is more similar to stout teeth than it is to slender teeth. Which it’s not. Remember, PAUP doesn’t actually care whether state 0 or 1 is primitive, so groups can be diagnosed due to sharing state 0 too. Maxillary teeth stout or maxillary teeth absent are two different conditions that aren’t related to each other. It’s as if your state were “eyes not green”, and it was grouping red-eyed taxa with eyeless taxa simply because they weren’t green-eyed.

      By “perverting” your matrix, I was actually fixing it. Just think of how little your character state makes sense as an evolutionary event. Is there a “tooth stout or absent” gene that could be inherited? Ask any phylogeneticist whether it’s proper to combine “toothless” with a tooth feature in one state, and you’ll see they agree with me. Toothless taxa need to be left unknown or inapplicable for characters involving tooth features. Honestly David, you just don't know what you're doing.