Teleocrater: a sister to Yarasuchus, not the earliest bird-line archosaur.

Unfortunately
another paper that was improperly vetted (refereed). I heard about this one on NPR when co-author Richard Butler was interviewed by the BBC.

Nesbitt et al. 2017
report: The relationship between dinosaurs and other reptiles is well established (1–4,) but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies.”

We’re in trouble from the opening salvo.
The large reptile tree (LRT) does not recover the same tree topology as these authors hypothesize (Fig. 1). And the sequence of dinosaurian features is not obscured in the LRT. There are plenty of fossils with transitional morphologies. Unfortunately, these authors either chose to ignore them or scored them haphazardly. Based on the theory that evolution happens with small changes the Nesbitt et al. tree topology (Fig. 1) is completely bonkers, adding unrelated taxa while excluding pertinent sisters to Teleocrater (here labeled under its new clade, Aphanosauria).

Figure 1. Aphanosauria according to Nesbitt et al. 2017. Two of these clades are unrelated to archosaurs. Marasuchus IS a dinosaur. Silesaurus is a poposaur more distantly related to dinos than crocs.

Figure 1. Aphanosauria according to Nesbitt et al. 2017. Two of these clades are unrelated to archosaurs. Marasuchus IS a dinosaur. Silesaurus is a poposaur more distantly related to dinos than crocs. Where are the crocs?

Nesbitt et al. report:
“H
ere we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch.” There is no such thing as an avian stem lineage. Avemetarsalia includes pterosaurs and dinosaurs, so it is a junior synonym for Reptilia in the LRT. The closest ancestors to dinosaurs were bipedal basal crocodylomorphs in the LRT. I don’t see them in figure 1. 
Teleocrater holotype.
NHMUK (N
atural History Museum, London, UK) PV 
R6795, a disassociated skeleton of one individual, including: cervical, trunk, and caudal vertebrae, partial pectoral and pelvic girdles, partial forelimb and hind limbs. 
Referred material.
Elements f
ound near the holotype, but from other 
individuals, which represent most of the skeleton and that are derived from a paucispecific bone bed containing at least three individuals.
Figure 2. The chimaera created by several specimens attributed to Telocrater. Even if all these piece do fit together like Nesbitt et al. indicate, Telocrater is closer to Yarasuchus and Ticinosuchus than it is to the last common ancestor of Archosauria.

Figure 2. The chimaera created by several specimens attributed to Teleocrater. Even if all these piece do fit together like Nesbitt et al. indicate, Teleocrater is closer to Yarasuchus and Ticinosuchus than it is to the last common ancestor of Archosauria. See figure 3.

The specimens that produced this reconstruction (Fig. 2)
are all associated. So there is great confidence that all of the bones are conspecific. The problem, once again, is taxon exclusion, and maybe a large dose of bad scoring (see below)

Figure 3. Telocrater to scale compared with likely sister taxa among the Ticinosuchidae in the LRT. Note the resemblance of the Telocerater maxilla to that of these sister taxa.

Figure 3. Teleocrater to scale compared with likely sister taxa among the Ticinosuchidae in the LRT. Note the resemblance of the Teleocerater maxilla to that of these sister taxa.

Oddly
the authors report that “Osteoderms are not preserved and were probably absent.” And yet their reconstruction (Fig. 2) has osteoderms in the black outline. What bias is present here?

Oddly
the authors report, Our phylogenetic analyses recovered Teleocrater in a clade containing Yarasuchus, Dongusuchus and Spondylosoma.” And yet they did not include Yarasuchus in their phylogenetic figure (Fig. 1). The latter two are know from scraps. Yarasuchus (Fig. 3) is much more complete. 

Problems with the Nesbitt et al. 2017 cladogram

  1. The outgroup for Prolacerta + Archosauriformes (Proterosuchus) is the unrelated lepidosaur, Mesosuchus.
  2. The unrelated thalattosaur, Vancleavea, nests between Erythrosuchus and the unrelated chanaresuchid, Tropidosuchus. None of these taxa even look alike!
  3. The Yarasuchus clade, and before it the Parasuchus clade gives rise to the pterosaurs DimorphodonEudimorphodon and another chanaresuchid, Lagerpeton, both purportedly in the lineage of dinosaurs. These are all actors pretending to be relatives. How is this possible that Nesbitt et al, and the referees and editors at Nature are not raising objections to this? This is total madness at the highest levels.

Need I go on???
Why is Teleocrater big news? Because the authors positioned it as an ancestor to dinosaurs. It may be, but it is buried deep, deep, deep in the lineage. Why was the relationship with Yarasuchus buried? You know why… it’s not as ‘sexy’ to the press.

Nesbitt et al. report,Aphanosauria…is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia.” Surprised to see they didn’t say, ‘pterosaurs and Tyrannosaurus rex.’ 

Folks, it’s all showmanship.
I’m sure the authors have all toasted their new paper in Nature by now. I hate seeing the subject of evolution twisted, torn and laid bare like this.

The real importance of Teleocrater
is its basal position in a clade I earlier called Ticinosuchidae, arising from basal rauisuchians, like Vjushkovia, giving rise to a wide variety of taxa like Aetosaurus and Arizonasaurus) while also giving rise to Decuriasuchus, which gave rise to poposaurs, like Turfanosuchus, and archosaurs, thus ultimately including dinosaurs.

References
Nesbitt SJ et al. (10 co-authors) 2017. The earliest bird-line archosaurs and the assemblof the dinosaur body plan. Nature doi:10.1038/nature22037. (online pdf)

1. Benton, M. J. & Clark, J. M. in The Phylogeny and Classification of the Tetrapods.
Volume 1: Amphibians, Reptiles, Birds. Systematics Association Special Volume
35A (ed. Benton, M. J.) 295–338 (Clarendon, 1988).
2. Gauthier, J. Saurischian monophyly and the origin of birds. Mem. Calif. Acad.
Sci. 8, 1–55 (1986).
3. Sereno, P. C. Basal archosaurs: phylogenetic relationships and functional
implications. Soc. Vertebr. Paleontol. Mem. 2, 1–53 (1991).
4. Sereno, P. C. The evolution of dinosaurs. Science 284, 2137–2147 (1999).
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2 thoughts on “Teleocrater: a sister to Yarasuchus, not the earliest bird-line archosaur.

  1. You seem very angry that nobody replicates your results and your misconceptions. Yes, misconceptions, and they’re not limited to the fact that you misspell Teleocrater as “Telocrater” at almost every occasion. Here goes:

    Based on the theory that evolution happens with small changes the Nesbitt et al. tree topology (Fig. 1) is completely bonkers

    Only if we were silly enough to believe that the fossil record is evenly and very densely sampled. It is neither, and that should be obvious; it is obvious to everyone except you.

    It isn’t even the case that the LRT doesn’t contain any gaps. It does – just not, perhaps, in the characters you happen to have considered.

    Marasuchus IS a dinosaur.

    Not even in the latest unpublished analysis. What characters put it inside in yours?

    Silesaurus is a poposaur

    That makes no sense that I can see. What characters put it there in the LRT?

    There is no such thing as an avian stem lineage.

    “Lineage” is a very wishy-washy word. I don’t like it. However, something extinct has to be more closely related to the birds than to anything else that survives today, and that’s what is meant by “avian stem lineage”.

    The closest ancestors to dinosaurs were bipedal basal crocodylomorphs in the LRT.

    No, dinosaurs aren’t crocodylomorphs.

    Your father is an ancestor of yours. Your uncle is not an ancestor of yours.

    And besides, why do you think any crocodylomorphs were bipedal? They all have those elongate proximal carpals that don’t make any sense if they weren’t used for quadrupedal locomotion.

    Oddly
    the authors report that “Osteoderms are not preserved and were probably absent.” And yet their reconstruction (Fig. 2) has osteoderms in the black outline. What bias is present here?

    And other than that you feel fine? Those are epidermal scales, obviously. They’re not osteoderms at all. The spikes of an iguana don’t contain any bones either!

    Oddly
    the authors report, “Our phylogenetic analyses recovered Teleocrater in a clade containing Yarasuchus, Dongusuchus and Spondylosoma.” And yet they did not include Yarasuchus in their phylogenetic figure (Fig. 1).

    …and…

    Why was the relationship with Yarasuchus buried?

    The figures that present their trees are their fig. 3 and their extended data figures 3, 4, 7 and 8. Your fig. 1 is, instead, modified from the left part of their ext. data fig. 5; the rest of that figure, which you’re not showing us, illustrates the distribution – on the tree – of the character states of which the “crocodile-normal ankle” is composed.

    I conclude that you glanced at the title and the abstract (so briefly you didn’t even manage to read the name Teleocrater), scrolled through the rest so quickly that you overlooked fig. 3 completely, scrolled through ext. data fig. 3 and 4 without reading the small print in them (the names, which include Yarasuchus), finally stopped when you saw the silhouettes in ext. data fig. 5, stopped there and got angry that Yarasuchus wasn’t explicitly in that figure.

    Seriously, what is wrong with you?

    None of these taxa even look alike!

    Look closer. Sounds trite, but I mean it seriously and literally.

    The Yarasuchus clade, and before it the Parasuchus clade gives rise to the pterosaurs

    For at least 12 years I’ve been telling you that leaves in a tree don’t give rise to each other – branches and nodes give rise to leaves. Not once have you reacted at all; every single time you’ve completely ignored this fact.

    Why?

    How is this possible that Nesbitt et al, and the referees and editors at Nature are not raising objections to this? This is total madness at the highest levels.

    It’s not. They simply understand things that you don’t know about.

    It’s strange how it never occurs to you that this could be the case.

    Why is Tel[e]ocrater big news? Because the authors positioned it as an ancestor to dinosaurs.

    See? They did no such thing.

    They found it to be a close relatives of the dinosaurs – not as an ancestor of anything. In fact, they didn’t find anything as an ancestor of anything else: there are OTUs at any of the nodes in any of their four trees.

    Folks, it’s all showmanship.

    Spend a little more thought on an issue before you call the people involved in it evil.

    arising from […] giving rise to […] while also giving rise to […] which gave rise to

    No.

    I repeat: you’re misreading the LRT. You’re misreading the tree that’s based on your own matrix.

    You don’t know how to read a phylogenetic tree. I’m sorry if that offends you, I can’t find another explanation for what you’re saying.

    • Thanks for the spell check! All fixed now.

      re: You seem very angry that nobody replicates your results and your misconceptions.

      Anger? No. Dismay, perhaps. Let’s encourage taxon inclusion.

      re: Only if we were silly enough to believe that the fossil record is evenly and very densely sampled. It is neither, and that should be obvious; it is obvious to everyone except you.

      To your point. it gets worse with taxon exclusion, better with taxon inclusion.

      re: It isn’t even the case that the LRT doesn’t contain any gaps. It does – just not, perhaps, in the characters you happen to have considered.

      Perhaps you meant taxa, not characters. And yes, between every two taxa, no matter how many are presented, you can find gaps. Even between juveniles and adults of the same species.

      re: Marasuchus IS a dinosaur.

      Not even in the latest unpublished analysis. What characters put it inside in yours?

      It’s a suite of characters you can read for yourself within the .nex file. If I were to list a few or a dozen, I would be doing a “Larry Martin.”

      re: Silesaurus is a poposaur

      That makes no sense that I can see. What characters put it there in the LRT?

      Same answer.

      re: something extinct has to be more closely related to the birds than to anything else that survives today, and that’s what is meant by “avian stem lineage”.

      The LRT finds troodontids, dromaeosaurids and a selection of theropodss as ‘avian stem lineage’ taxa.

      re: The closest ancestors to dinosaurs were bipedal basal crocodylomorphs in the LRT.

      No, dinosaurs aren’t crocodylomorphs.

      I did not say dinosaurs are crocodylomorphs. I said, “the closest ancestors…”

      re: And besides, why do you think any crocodylomorphs were bipedal? They all have those elongate proximal carpals that don’t make any sense if they weren’t used for quadrupedal locomotion.

      You’ll pulling a Larry Martin on me. In the LRT the crocodylomorphs closest to the dino line did not have elongate proximal carpals. The LRT indicates that this trait developed twice, once inside the crocodylomorpha, and once in the Pseudhesperosuchus clade, reaching a separate acme in Trialestes. Disparate limb length in basalmost LRT archosaurs indicates bipedality.

      re: Those are epidermal scales, obviously. They’re not osteoderms at all. The spikes of an iguana don’t contain any bones either!

      But there’s no evidence for giant epidermal scales…

      re: I conclude that you glanced at the title and the abstract (so briefly you didn’t even manage to read the name Teleocrater), scrolled through the rest so quickly that you overlooked fig. 3 completely, scrolled through ext. data fig. 3 and 4 without reading the small print in them (the names, which include Yarasuchus), finally stopped when you saw the silhouettes in ext. data fig. 5, stopped there and got angry that Yarasuchus wasn’t explicitly in that figure.

      You know what I’m thinking. You what I’m feeling. How is this scientifically possible? You might be guessing. And you might be projecting. Most writers do.

      re: The Yarasuchus clade, and before it the Parasuchus clade gives rise to the pterosaurs

      For at least 12 years I’ve been telling you that leaves in a tree don’t give rise to each other – branches and nodes give rise to leaves. Not once have you reacted at all; every single time you’ve completely ignored this fact.

      No, Dave, I answer you every time. To your point, and to my point there is one node that gave rise to pterosaurs and parasuchians in the LRT, and it is a late Devonian to Viséan basal amniote. Anything of that sort in the Triassic can only be recovered by taxon exclusion.

      re: Why is Tel[e]ocrater big news? Because the authors positioned it as an ancestor to dinosaurs.

      See? They did no such thing. They found it to be a close relatives of the dinosaurs

      Dave, they found it to be in the avian lineage. Dinosaurs are in the avian lineage, too. You and I both know no one will ever find the precise fossil ancestors that begat dinosaurs. But paleontologists dumb that down for broad public consumption. And that’s okay… as long as it isn’t way off track, like it is here.

      re: Spend a little more thought on an issue before you call the people involved in it evil.

      Reread what I wrote and you wrote. I said ‘showmanship’. You said evil. Big difference. To your earlier point, anger is often equated with evil. Maybe you just gave yourself away with a word that should have been edited for another more precise concept.

      re: You don’t know how to read a phylogenetic tree. I’m sorry if that offends you, I can’t find another explanation for what you’re saying.

      Then just read the tree without my comments. Teleocrater is separated from birds and dinosaurs by many intervening nodes with even more taxa at their leaves. Sometimes taxa are worthy of dinosaurian and avian headlines. This one is not.

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