Quick note: progress behind the scenes

Apologies
for not getting to the latest comments. I have not opened a week’s worth of snail-mail and bills, so you’re not alone.

Some changes to the LRT
happened while reexamining the data on which the matrix scores are input.

  1. Tulerpeton now nests between Ichthyostega and Eucritta.
  2. Bystrowiella now nests with Solenodonsaurus.

That’s really not a lot of news
for the amount of work that went into getting those. All the related taxa had little changes to toes, teeth, etc. …all toward a greater understanding of what’s going on here. It all started with attempting a lateral view of the skull of Bystrowiella (Fig. 1; (Witzmann and Schoch 2017; Middle Triassic), and see where it led…

Figure 1. Bystrowiella skull in lateral view. Note the large tooth roots on the premaxilla. we don't know how long those buck teeth would have been.

Figure 1. Bystrowiella skull in lateral view. Note the large tooth roots on the premaxilla. we don’t know how long those buck teeth would have been.

References
Witzmann F and Schoch RR 2017. Skull and postcranium of the bystrowianid Bystrowiella schumanni from the Middle Triassic of Germany, and the position of chroniosuchians within Tetrapoda. Journal of Systematic Palaeontology 29 pp.

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Halszkaraptor: what a story!

Published in Nature today
a Mongolian Late Cretaceous theropod that was rescued from the black market! It is supposed to be aquatic… but is it?

Figure 1. Halszkaraptor escuillei was originally considered an aquatic basal dromaosaur, but here nests with Shuvuuia, a sprinting biped.

Figure 1. Halszkaraptor escuillei was originally considered an aquatic basal dromaosaur, but here nests with Shuvuuia, a sprinting biped. It might not have been this chubby in the torso. All art is from Cau et al. 2017.

Halszkaraptor escuilliei (Cau et al. 2017; Late Cretaceous, Fig. 1) was originally considered an aquatic basal dromaeosaur related to Mahakala, but here Halszkaraptor nests with ShuvuuiaHaplocheirus and other non-aquatic sprinting dromaeosaurids. Manual digit 3 was the longest, but the thumb had the largest claw. The naris was displaced posteriorly. The fossil is preserved in 3D, largely articulated.

Figure 1. Shuvuuia and Mononykus to scale in various poses. The odd digit 1 forelimb claws appear to be retained for clasping medial cylinders, like tree trunks. The forelimb is very strong. Perhaps these taxa rest vertically and run horizontally. Click to enlarge.

Figure 2. Shuvuuia and Mononykus to scale in various poses. The odd digit 1 forelimb claws appear to be retained for clasping medial cylinders, like tree trunks. The forelimb is very strong. Perhaps these taxa rest vertically and run horizontally. Click to enlarge.

The Cau et al. cladogram
has many more bird-like theropods than the LRT. The taxa that nest together with Halszkaraptor in the LRT are sprinkled throughout the Cau et al. cladogram. In fact, all of the theropods that the two cladograms have in common nest in completely different nodes and leaves, except Haplocheirus nests in the same clade as Shuvuuia in both trees. Is this a case of taxon exclusion on the part of the LRT? Or just what happens when you score different traits? No reconstructions of sister taxa were provided.

FIgure 2. Subset of the LRT focusing on pre-bird theropods.

FIgure 2. Subset of the LRT focusing on pre-bird theropods. The taxa in the Velociraptor clade are sprinkled throughout the Cau et al. cladogram of theropods.

Let’s look at the pertinent parts of the Cau et al. abstract:
“Propagation X-ray phase-contrast synchrotron microtomography of a well-preserved maniraptoran from Mongolia, still partially embedded in the rock matrix, revealed a mosaic of features, most of them absent among non-avian maniraptorans but shared by reptilian and avian groups with aquatic or semiaquatic ecologies.

“This new theropod, Halszkaraptor escuillieigen. et sp. nov., is related to other enigmatic Late Cretaceous maniraptorans from Mongolia in a novel clade at the root of Dromaeosauridae. This lineage adds an amphibious ecomorphology to those evolved by maniraptorans: it acquired a predatory mode that relied mainly on neck hyperelongation for food procurement, it coupled the obligatory bipedalism of theropods with forelimb proportions that may support a swimming function, and it developed postural adaptations convergent with short-tailed birds.”
What about this theropod screams, “I’m aquatic!!” ?? This is one I just don’t see.
In the LRT
Halszkaraptor does not nest with other aquatic taxa. The neck is not particularly long compared to coeval Mononykus (Fig. 2), which has never been considered aquatic. The skull is very much like that of coeval Shuvuuia
Described in the press
as one of the oddest fossil yet found. This adjective usually gets attached to errors in identification. Halszkaraptor is not that odd. NatGeo reports, “Like modern aquatic predators, this dinosaur’s face seems to have had an exquisite sense of touch, useful for finding prey in murky waters. Its small teeth would have helped it nab tiny fish, and its limber backbone and flipper-like forelimbs suggest that it cut through the water with ease.”
This added later:
Apparently others have also seen the Shuvuuia connection. Author Andrea Cau listed 25 traits here that distinguish Halszkaraptor from Shuvuuia, but are found in dromaeosaurids. Perhaps this could all be cleared up easily, because in the LRT, Shuvuuia IS also a dromaeosaurid, not a distantly related theropod, as it nests in Cau et al. 2017.

References
Cau A, et al. 2017. Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs. Nature. doi:10.1038/nature24679

wiki/Halszkaraptor
wiki/Shuvuuia

Pandion, the osprey, joins the LRT

And the osprey,
Pandion haliaetus (Linneaus 1758) joins the large reptile tree (LRT, 1124 taxa) at the base of (owls + swifts) + (Old World vultures + falcons). The secretary bird, Sagittarius, and the terror birds are proximal outgroups.

Figure 1. Pandion, the osprey, nests at the base of the birds of prey, sans the secretary bird and seriema.

Figure 1. Pandion, the osprey, nests at the base of the birds of prey, sans the secretary bird and seriema.

So the osprey is a basal
short-legged, arboreal birds-of-prey.

Wikipedia reports,
“The osprey differs in several respects from other diurnal birds of prey. Its toes are of equal length, its tarsi are reticulate, and its talons are rounded, rather than grooved. The osprey and owls are the only raptors whose outer toe is reversible, allowing them to grasp their prey with two toes in front and two behind. It has always presented something of a riddle to taxonomists, but here it is treated as the sole living member of the family Pandionidae, and the family listed in its traditional place as part of the order Falconiformes.”

References
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

wiki/Osprey

 

Old data (from 1896) nests the elephant bird, Aepyornis, with the ostrich, Struthio

Longtime readers know
I like to make repairs and get things right, whether working from published papers or my own images and data. And longtime readers know I don’t always get things right the first time, usually for good reason (see below). I’ve been looking for Andrews 1896 for several weeks and finally got it. All the earlier problems could have been avoided if I had the data earlier that I have now. Alas, that’s just how it goes…

Figure 1. Aepyornis maximus along with eggs, the largest known. The new skull replaces the original one.

Figure 1. Aepyornis maximus along with eggs, the largest known. The new skull replaces the original one.

Earlier data on the skull of the elephant bird,
Aepyorniscame from a photograph of a commercially available restored cast. Unfortunately, the restoration included a little too much imagination and did not match the only other data currently (and most recently) available (Fig. 2, Andrews 1896).

The data from the embryo in the giant egg attributed to Aepyornis,
did not contribute to the current matrix scoring. That would be akin to creating a chimaera. However, after the fact, it’s noteworthy that the embryo still has ostrich traits not found in the present adult skull data for Aepyornis. The fragile palatal and cheek regions were not preserved or collected in the adult. The fragile cheek regions were not yet developed (or lost in the debris) of the embryo.

Figure 4. NatGeo embryo compared to Struthio and adult Aepyornis. The original maxilla is reinterpreted as the palatine. The original premaxilla is a fused premaxilla + maxilla. The original Nat Geo skull was put together in computer software from scattered parts. Mesethmoid inverted in revision. Aepyornis does not have bulbous squamosals found in Struthio and the NatGeo embryo. Not to scale.

Figure 2. NatGeo embryo compared to Struthio and adult Aepyornis. The original maxilla is reinterpreted as the palatine. The original premaxilla is a fused premaxilla + maxilla. The original Nat Geo skull was put together in computer software from scattered parts. Mesethmoid inverted in revision. Aepyornis does not have bulbous squamosals found in Struthio and the NatGeo embryo. Not to scale. The mystery of the embryo is coming into clearer focus with the latest elephant bird skull data and taxonomy.

All earlier posts
and ReptileEvolution.com pages regarding Aepyornis have been repaired. Good science makes repairs all the time. Better data is always welcome. Every hypothesis remains hypothetical, until it is confirmed over and over again through testing.

Using commercially available skulls for data
is still a good idea, but it’s also a good idea to see which parts are real and which are restored with clay. I don’t know if several skull parts from several specimens of Aepyornis were all put together to produce the skulls currently found in museums and skull shops. Andrews 1896 reports the material he published came from two. Better to take data from one specimen than to make a chimaera of several specimens, because problems like this tend to happen. Sometimes you take what you can get.

Figure x. Bird giants in the bird subset of the LRT.

Figure 3. Bird giants in the bird subset of the LRT.

This should make certain readers happy
that Aepyornis returns to the ratites. I’m happy that better data has come forth. The latest DNA tests prefer Aepyornis to nest with the kiwi. Morphology leans toward the ostrich. With the new nesting of the elephant bird Casuarius, the cassowary, nests between tinamous and ostriches + elephant birds.

References
Andrews CW 1896. On the skull, sternum, and shoulder-girdle of Aepyornis. Ibis, Seventh Series, 2:376-389.
Balanoff AM 2003. Osteological description of an embryonic elephant bird (Ratitae: Aepyornis) using high-resolution X-ray computed tomography, with a discussion of growth in Aepyornis. M.S. thesis, The University of Texas, Austin, Texas, 175 pp.
Balanoff AM and Rowe T 2007. Osteological description of an embryonic skeleton of the extinct elephant bird, Aepyornis (Palaeognathae: Ratitae). Journal of Vertebrate Paleontology 27(sp9):1–53.
Geoffroy Saint-Hilaire I 1851. [Note sur les onze espèces nouvelles do Trochilidés de M. Bourcier.] Compt. Rend. de l’Acad. Sci 32:188.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.
Temminck 1815. Histoire naturelle generale des pigeons et des gallinaces.
Accompagne de planches anatomiques. 3: 552–747

wiki/Rhynchotus
wiki/Cassowary
wiki/Ostrich
wiki/Aepyornis

New rhynchocephalian, Vadasaurus, is not a pleurosaur ancestor

Once again
taxon exclusion bites a paper on the set up and conclusion.

Bever and Norell 2017 bring us
a perfect Solnhofen (Late Jurassic) fossil of a small rhynchocephalian, Vadasaurus herzogi (Figs. 1,2) that they mistakenly promote as a pleurosaur ancestor (Fig. 5). We looked at the real pleurosaur ancestors several years ago here.

Figure 1. Vadasaurus is a perfectly preserved Solnhofen fossil rhynchocephalian.

Figure 1. Vadasaurus is a perfectly preserved Solnhofen fossil rhynchocephalian. PILs and colors added. The pelvis is semi-perforate. The proximal tarsus is not co-ossified.

Vadasaurus herzogi (Bever and Norell 2017, Late Jurassic) AMNH FARB 32768, was originally nested between Sapheosaurus + Kallimodon and the aquatic pleurosaurs, Pleurosaursus and Palaeopleurosaurus. Here Vadasaurus nests very closely with Leptosaurus, a terrestrial taxon omitted originally. Close examination of photos in the literature (Fig. 2) shows that Bever and Norell overlooked the supratemporal, the jugal’s quadratojugal process and added a mandible fenestra that is not present. The lack of co-ossificiation in the astragalus and calcaneum is a trait that is retained by all later taxa, including the trilophosaurs, azendohsaurs and rhychosaurs. Priosphenodon, listed in both competing trees, is the outgroup for the Rhynchosauria.

Figure 2. The skull of Vadasaurus showing the jugal's quadratojugal process, the portion of the postfrontal entering the upper temporal fenestra and the mandible interpreted differently than Bever and Norell 2017.

Figure 2. The skull of Vadasaurus showing the jugal’s quadratojugal process, the portion of the postfrontal entering the upper temporal fenestra and the mandible interpreted differently than Bever and Norell 2017.

The large reptile tree (LRT, 1121 taxa, subset Fig. 3) does not include all of the taxa employed by Bever and Norell 2017. In like fashion, Bever and Norell do not include all of the rhynchocephalian taxa employed by the LRT.

Here, with high Bootstrap scores
(Fig. 3) the LRT nests Pleurosaurus with Megachirella at the base of the Rhynchocephalia (Fig. 3). Palaeopleurosaurus nests separately, with Ankylosphenodon (Fig. 5), still close to the base of the clade. Kallimodon nests close to Vadasaurus in the Bever and Norell tree, but with Sphenodon in the LRT. Other differences also occur. Homeosaurus is included in the Bever and Norell tree, but nests outside the Rhynchochephalia in the LRT.

Figure 3. Subset of the LRT nesting Vadasaurus with Leptosaurus in the Rhynchocephalia

Figure 3. Subset of the LRT nesting Vadasaurus with Leptosaurus in the Rhynchocephalia

The Bever and Norell cladogram
(Fig. 4) is very poorly supported with most nodes <50 and only one node above 80. The outgroup is wrong, based on results recovered by the LRT which tests a over 1000 possible outgroup candidates. Youngina is completely unrelated. It nests close to the archosauriform, Proterosuchus. Pristidactylus is am extant squamate also unrelated to rhynchocephalians.

By contrast,
the subset of the LRT (Fig. 3) is strongly supported with high Bootstrap scores throughout. Outgroups going back to basal tetrapods are documented.

Figure 4. Cladogram from Bever and Norell 2017 with the addition of Vadasaurus. When Bootstrap support is below 50 it is not marked.

Figure 4. Cladogram from Bever and Norell 2017 with the addition of Vadasaurus. When Bootstrap support is below 50 it is not marked. This tree does not include the correct outgroup and the Rhynchosauria + Trilophosaurus and other taxa.

The Bever and Norell paper does not provide reconstructions,
but ReptileEvolution.com does (Fig. 5). Chronology is all over the place in this clade. Megachirella and BRSUG 29950, at the base of this clade, are both Middle Triassic. Pleurosarus is Late Jurassic. Ankylosphenodon is Early Cretaceous. Sphenodon is extant.

Figure 1. Pleurosaurus and Palaeopleurosaurus to scale with sisters.

Figure 5. Pleurosaurus and Palaeopleurosaurus to scale with sisters.

When Megachirella, Leptosaurus and other taxa
not employed by Bever and Norell are deleted from the LRT, the topology of the tree does not change.

Figure 6. Leptosaurus was omitted by Bever and Norell. Note the triangular skull, gracile mandible, radiale and other traits reported by the authors.

Figure 6. Leptosaurus was omitted by Bever and Norell. Note the triangular skull, gracile mandible, radiale and other traits reported by the authors.

Bever and Norell report that Vadasaurus is:
“Diagnosed in an exclusive clade with Pleurosauridae based on

  1. a triangular skull in the dorsal view,as in Leptosaurus (Fig. 6)
  2. posteriorly tapering maxilla, as in Leptosaurus (Fig. 6)
  3. posteriorly tapering palatine, – no, it’s posteriorly round in Vadasaurus (Fig. 2)
  4. moderately open interpterygoid vacuity, – not true or not visible (Fig. 2)
  5. pterygoid participation in the suborbital fenestra,– as in Brachyrhindon
  6. low angle of the mandibular symphysis,,– not any lower than LRT sister taxa
  7. gracile lower jaw,– not any more than LRT sister taxa
  8. jaw joint positioned dorsal to the maxillary tooth row, – not true in any case
  9. an unossified radiale. – not true, displaced
  10. a dorsoventrally compressed and elongate skull, – not true.
  11. and elongate external nares.” – also in Clevosaurus and Sphenotitan, not exposed in Leptosaurus (Fig. 6).

To their credit
Bever and Norell traced the photos, probably in Photoshop. That makes the alignment of the drawing with the photo perfect. At this point, all they need to do is start coloring bones in the DGS style (Fig. 2) and expand that taxon list.

References
Bever GS and Norell MA 2017. A new rhynchocephalian (Reptilia: Lepidosauria) from the Late Jurassic of Solnhofen (Germany) and the origin of the marine Pleurosauridae. Royal Society open scence. 4: 170570. http://dx.doi.org/10.1098/rsos.170570

You heard it here first: Daemonosaurus is an ornithischian

This one snuck under my radar
until Professor Thom Holtz mentioned it on the Dinosaur Mailing List. Writing about the Baron et al 2017 reply to Langer et al. we looked at earlier, Holtz wrote: “Novel discovery is Daemonosaurus as a basal ornithischian!!” (Fig. 1).

Actually that confirms a hypothesis of relationships
first recovered here back in 2011 when the large reptile tree (LRT, 1120 taxa) nested Daemonosaurus with the Ornithischia. So, the Baron et al. results confirm the earlier Peters 2011 discovery.

Figure 1. Here Daemonosaurus nests with basal ornithischians, not theropods, matching a nesting first recovered here in the LRT in 2011.

Figure 1. In Baron et al. 2017 Daemonosaurus nests with basal ornithischians, not theropods, matching a nesting first recovered here in the LRT in 2011.

As noted earlier, the Baron et al study is lacking a long list of pertinent taxa. Taxon exclusion is often the chief problem in phylogenetic analyses that rely on tradition.

Figure 1. Skulls of Daemonosaurus, Haya and Jeholosaurus to scale.

Figure 2. Skulls of Daemonosaurus, Haya and Jeholosaurus to scale. These taxa nest together in the LRT.

Those who dislike the results recovered here
without a PhD and without seeing the specimens firsthand should note the growing list of taxa first recovered in the LRT that years later find confirmation in later studies by other workers.

References
Baron M.G., Barrett P.M. 2017 A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs. Biology Letters 13, 20170220.
Baron MG, Norman DB and Barrett PM 2017.
 xxxx Nature 543501–506;  doi:10.1038/nature21700
Baron MG, Norman DB and Barrett PM 2017. Baron et al. reply. Nature 551: doi:10.1038/nature24012
Langer et al. (8 co-authors) 2017. Untangling the dinosaur family tree. Nature 551: doi:10.1038/nature24011

The origin of giant birds: Phorusrhacos, the giant secretary bird

Figure 1. Phorushacids to scale. The extant Sagittarius is in color at lower right.

Figure 1. Phorushacids to scale. The extant Sagittarius is in color at lower right. Considering how closely Sagittarius looks like these taxa, one might be surprised to hear that Cariama (Fig. 4) is widely considered the extant relative. Cariama is not the sister in the LRT.

Traditionally
the seriema (genus: Cariama; Fig. 4) has been allied to the ‘terror’ birds, the phorusrhacids (Fig. 1), but it does not have the elevated external naris and deep beak found in the secretary bird (genus: Sagittarius, Figs. 1, 3). Sagittarius also has a more robust set of cervicals. Heretically, in the large reptile tree (LRT, 1120 taxa), the secretary bird of Africa is closer to phorusrhacids of South America.

Figure 3. Skull of Phorusrhacos, a giant terror bird.

Figure 3. Skull of Phorusrhacos, a giant terror bird in three views.

The terror-bird clade is represented in the fossil record
all the way back to the mid-Paleocene (Paleopsilopterus, no skull material known).

Figure 2. Sagittarius (secretary bird) and Cariama (seriema). While clearly related, these two nest at the base of two different major bird clades.

Figure 4. Sagittarius (secretary bird) and Cariama (seriema). While clearly related, these two nest at the base of two different major bird clades. Sagittarius is allied with terror birds. Cariama is allied with flamingo.

Sagittarius serpentarius (Miller 1779) The extant secretary bird is a chiefly terrestrial bird with long legs capable of short flights. It is a sister to Llallawavis, an ancient ‘terror bird.’

Figure x. Bird giants in the bird subset of the LRT.

Figure 5. Bird giants in the bird subset of the LRT.

References
Alvarenga, HMF and Höfling E 2003. Systematic revision of the Phorusrhacidae (Aves: Ralliformes). Papéis Avulsos de Zoologia 43(4): 55-91.
Statius Müller PL 1776. Des Ritters Carl von Linné Königlich Schwedischen Leibarztes &c. &c. vollständigen Natursystems Supplements- und Register-Band über alle sechs Theile oder Classen des Thierreichs. Mit einer ausführlichen Erklärung. Nebst drey Kupfertafeln.Nürnberg. (Raspe).

wiki/Phorusrhacos
wiki/Sagittarius