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

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Nycteroleter: which data is better?

Nycteroleter
(Efremov 1938; Middle Permian) was just added to the large reptile tree (LRT, 1035 taxa). The GIF movie shown here (Fig. 1) shows the data I had to work with. Note the differences.

Figure 1. Nycteroleter inept us and the two data sources used in scoring this taxon. The one with the smaller premaxilla in dorsal view nests with fewer autapomorphies in the LRT.

Figure 1. Nycteroleter inept us and the two data sources used in scoring this taxon. The one with the smaller premaxilla in dorsal view nests with fewer autapomorphies in the LRT.

This is not a case of ‘who do you trust?’
because we can figure out which is the more accurate skull by using the LRT.

I let the LRT choose which dataset
had fewer autapomorphies, since I had no direct access to fossils. Note the less accurate skull also mislabels the cranial corners as tabulars. They should be labeled supratemporals. Nycteroleter nests with Nyctiphruretus in the LRT.

If I’m wrong, 
I’ll make the changes if and when better data comes in.

References
Efremov JA 1938. Some new Permian reptiles of the U.S.S.R. Comptes Rendus (Doklady), 19: 771–776.

Misinformation on the palate of Kunpengopterus

Cheng et al. 2017 present
a new complete but slightly damaged specimen of Kunpengopterus, IVPP V 23674.

The new Kunpegnopterus IVPP V 23674.

The new Kunpegnopterus IVPP V 23674.

Cheng et al. provided a new palate reconstruction
that could use a little DGS to better inform the reader and the the authors (Fig. 2, 3). Cheng et al. think they have found some new medial projections toward the back of the palate. Actually they are looking at broken off lateral pieces of the ecto-palatine (ectopterygoid fused to palatine).

Fig. 2. The skull of IVPP V 23674 colorized using DGS alongside the original description.

Fig. 2. The skull of IVPP V 23674 colorized using DGS alongside the original description.

And
here’s a closeup of the palate in dorsal view (Fig. 3). They relied on Wellnhofer 1978 for palate identification. That was when the anterior palate was considered the palatine as it seems to be here, but perhaps fused to the maxilla??. That must be the revision shown here based on Kellner 2013, which I have not read. Ever since Peters 2000, by comparison with Macrocnemus (acknowledged in Kellner 2013), and later by Osi et al. 2010, looking at Dorygnathus, the entire pterosaur palatal plate has been considered the maxilla, as it is here using colors (Fig. 3).

Fig. 3 Kunpengopterus IVPP V 23674 palate in dorsal view alongside original interpretation. Watch out for those broken bones. They sometimes end up in places a wee bit from their origins.

Fig. 3 Kunpengopterus IVPP V 23674 palate in dorsal view alongside original interpretation. Watch out for those broken bones. They sometimes end up in places a wee bit from their origins. And don’t you just hate 1 point lines telling you where the bones are? Colors are much more informative!

It’s really tough
when the broken bone appears to follow the contours of the unbroken bones, as they do here (Fig. 3). That’s where it helps to know the pattern of the palate in ALL pterosaurs. So exceptions like this can be reexamined, looking for the cracks that should not be there.

In similar fashion, here’s a pelvis
(Fig. 4) from the same specimen that appeared to Cheng et al to have a really deep pubis when the reality is more mundane.

Figure 4 Kunpengopterus pelvis with DGS colors identifying the anterior ilium detached from the posterior ilium and the false deep pubis.

Figure 4 Kunpengopterus pelvis with DGS colors identifying the anterior ilium detached from the posterior ilium and the false deep pubis. Note the original drawing in figure 1 that extends the pubis too deep by incorporating the inverted prepubis that match the contours of the ischium. 

References
Cheng X, Jiang S-X, Wang X-L, Kellner AWA 2017. New anatomical information of the wukongopterid Kunpengopterus sinensis Wang et al., 2010 based on a new specimen. PeerJ 5:e4102; DOI 10.7717/peerj.4102
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Osi A, Prondvai E, Frey E and Pohl B 2010. New Interpretation of the Palate of Pterosaurs. The Anatomical Record 293: 243-258.

Dinosaur outgroup taxon: Turfanosuchus

It was the Middle Triassic when
a sister to Turfanosuchus evolved into the basalmost dinosaur, Herrerasaurus (Figs. 1, 2)

Figure 1. Turfanosuchus compared to Herrerasaurus, the basalmost dinosaur.

Figure 1. Turfanosuchus compared to Herrerasaurus, the basalmost dinosaur. Lower image to scale.

Figure 2. Skull of Turfanosuchus compared to Herrerasaurus, the basalmost dinosaur.

Figure 2. Skull of Turfanosuchus compared to Herrerasaurus, the basalmost dinosaur.

Quick one today.
I’ll let the pictures tell the story…

References
Novas FE 1994. New information on the systematics and postcranial skeleton of Herrerasaurus ischigualastensis (Theropoda: Herrerasauridae) from the Ischigualasto
Reig OA 1963. La presencia de dinosaurios saurisquios en los “Estratos de Ischigualasto” (Mesotriásico Superior) de las provincias de San Juan y La Rioja (República Argentina). Ameghiniana 3: 3-20.
Sereno PC and Novas FE 1993. The skull and neck of the basal theropod Herrerasaurusischigualastensis. Journal of Vertebrate Paleontology 13: 451-476. doi:10.1080/02724634.1994.10011525.
Young CC 1973. [On a new pseudosuchian from Turfan, Sinking (Xinjiang).] Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology of the Academia Sinica, Series B 10:15-37.

wiki/Herrerasaurus
wiki/Turfanosuchus

The evolution of Bugs Bunny

I saw this online and thought I’d save it for a rainy day.
I thought it worth sharing.

Wikipedia compiled this (Fig. 1), convergent, of course with the real rabbit series: MonodelphisPtillocercus > Tupaia > Zalambdalestes > GomphosOryctolagus

Figure 1. The evolution of our favorite 'wascally rabbit' Bugs Bunny.

Figure 1. The evolution of our favorite ‘wascally rabbit’ Bugs Bunny.

Earlier we looked at some spectacular Daffy Duck skeletons. (BTW, I note the included links have largely evaporated). The artist is Hyungkoo Lee.

But we still can link
to other artists who have done similar studies, like Michael Paulus.

Figure 2. I concocted this Ptero Road Runner for a 1990s SVP symposium.

Figure 2. I concocted this Ptero Road Runner for a 1990s SVP symposium on bipedal pterosaurs. Still surprisingly accurate compared to competing depictions!

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Hamipterus egg accumulation: Wang et al. 2017

Earlier
here and here we looked at the 3-D eggs of Hamipterus, a basal ornithocheirid from Early Cretaceous China. The eggs are scattered in and amongst a wide size/age range of disarticulated, but 3-D fossils. So, according to the authors, the eggs were buried, then bones and eggs were transported by storms, as if bulldozed. No embryos were reported from those eggs. No explanation why the pterosaurs did not fly away in the face of the storm, nor why more sediment wasn’t packed on the buried eggs during the storm.

Today
comes news from this expanding treasure trove site with embryo bones at several stages of development in 16 eggs out of hundreds! That’s good news because full-term embryos (= hatchlings) are identical to parents and eggs keep all the bones from an individual in a neat little package so we can finally put together what Hamipterus looked like.

But that’s not the picture the authors paint.
They said, “some bones lack extensive ossification in potentially late-term embryos, suggesting that hatchlings might have been flightless and less precocious than previously assumed.” Point-by-point:

  1. No nests were found.
  2. 215+ eggs were found
  3. Eggs appeared in moderate size variation
  4. The large number of accumulated eggs (Fig. 1) indicates they were laid by different females
  5. Some were subjected to differential water uptake during transport
  6. Internal content(?) observed in 42 eggs, 16 had embryos
  7. Bones not concentrated on the bottom half of the egg, as in dinosaurs
  8. No embryo is complete. One to several bones only in each of the 16 eggs.
  9. No teeth found in embryos.
  10. The most complete embryo had a lower jaw of 17mm. That’s 4% the size of the largest adult when other full-term pterosaur embryos are 12.5% (1/8) at hatching. So these were not full-term embryos ready to hatch.
  11. In a 2.2m section, eight layers with pterosaur bones have been identified, four of which show egg concentrations in a vertical distance of 1.4 m.

The authors note and conclude:
“This suggests that the hind limbs have developed more rapidly compared to the forelimbs and might have been functional right after the animal hatched. Thus, newborns were likely to move around but were not able to fly, leading to the hypothesis that Hamipterus might have been less precocious than advocated for flying reptiles in general (6) and probably needed some parental care.”

No. Think again.
Pterosaur mothers carried their eggs inside their bodies until just before hatching. That gives their babies warmth and protection until they are ready to hatch. They could do this because they are lepidosaurs, as phylogenetic analysis AND egg shell thickness and pliability tells us.

Figure 1. From Wang et al. 2017, a pterosaur egg and bone accumulation. Eggs float. So do hollow pterosaur bones.

Figure 1. From Wang et al. 2017, a pterosaur egg and bone accumulation. Eggs float. So do hollow pterosaur bones.

Sedimentology report:
“This sedimentological data, associated with the exceptional quantity of eggs and bones, indicate that events of high energy such as storms have passed over a nesting site, causing the eggs to be moved inside the lake where they floated for a short period of time, becoming concentrated and eventually buried along with disarticulated skeletons.”

Bottom line and biggest problem:
The authors assume the eggs were laid. That’s because they think pterosaurs are archosaurs. Birds and crocs are archosaurs and they lay their eggs at an early stage of fertilization. Lepidosaurs wait to lay their eggs, sometimes until the moment before hatching.

Alternative hypothesis:

  1. Mass death of several year-classes of pterosaurs on beach due to lake burping deadly carbon dioxide. That stops the parents from flying away.
  2. Dessication and insect decomposition reveals eggs inside of female skeletons. This takes just a few days to a week and allows skeletons to easily separate into individual bones (Fig. 1)
  3. Later rising waters (storms optional, melting snow pack will do), overwhelms beached skeletons and exposed eggs. Even a few extra inches of water would be enough for this.
  4. Eggs float. So do pterosaur bones
  5. Wind/ripples push eggs and bones together back against beach bank corner where they accumulate. (This happened several times over dozens to hundreds of years, but not annually.)
  6. Water recedes leaving eggs en masse along with settling disarticulated individual bones of parents and kin
  7. Burial process is later completed with airborne or waterborne sediments overwhelming the bones and eggs in situ.
  8. To point #3 above: moderate egg size variation, we also see this in the chicken eggs we get at our local grocery, but pterosaurs kept growing throughout their lives and larger ones would tend to lay bigger eggs, though this has not been conclusively demonstrated, it seems broadly logical.

Evidently
the lake burping did not always coincide with the pterosaurs flocking together. But it happened four times to a portion of the flock, perhaps over hundreds of years, and evidently at ‘the back of the room where bad things happen’.

References
Wang X and 16 co-authors 2017. Egg accumulation with 3D embryos provides insight into the life history of a pterosaur. Science 358:1197–1201.

Would you like to read a rejection notice, or two?

In the past week
I submitted a comment to Royal Society Proceeedings B on Foth and Joyce 2017. In it I suggested that the origin of turtles was diphyletic and that would affect the placement of the basalmost turtle in the work of Foth and Joyce.

Referee number 1 wrote:
“This paper is unsuitable for Proceedings B (or any scientific journal) and should be rejected. It is ostensibly a response to a recent paper by Foth & Joyce on the disparity of the turtle skull over time, but in reality it doesn’t address this study at all, but is a back-handed attempt by the author to publish an iconoclastic phylogenetic analysis based on an inadequate dataset riddled with errors and methodological flaws. Sorry, there is no way to be kind about this manuscript.”

Referee number 2 (Walter Joyce, one of the original authors) wrote:
“the attached manuscript by David Peters is a response to an article I published earlier this year with Christian Foth in Proceedings B regarding the evolution of cranial disparity in turtles (Foth and Joyce 2017). Although I welcome any scientific debate regarding this paper, I would like to suggest outright rejecting this contribution for one single reason: It is an open trade secret that David Peters has been developing an enormous phylogeny of reptiles that produces highly outlandish results. One such outlandish result is the polyphyletic origin of turtles. This undertaking has been submitted to many journals over the years and has been rejected every time, as basic tenants of sound cladistic analysis are not followed therein, mostly an adherence to the use of character observations that can be reproduced by people who are not David Peters. I am certain that countless scientists invested countless hours in providing sound arguments why this tree should be rejected and I will therefore save myself the work here. If anything, this phylogeny should receive full peer review in a standalone publication, and not be slipped into the sphere of published scientific literature as part of a not-quite appropriate criticism of Foth and Joyce (2017).”

And here is my reply to the editors:
“Critical thinking is a requirement in science and I’ve had a few hours now to critically think about the replies I received from the two referees. I hope these comments will help you in future endeavors.

1. You already know that referees should be unbiased when they approach a manuscript. Asking Dr. Joyce to be a referee runs counter to that ideal. After all, I was commenting on his paper. His comments should have been requested only after two unbiased referees had ok’d the manuscript for publication.

2. Some referees like to accept manuscripts knowing ahead of time they will reject them. Is there any method you use to prevent this?

3. Whenever I review a manuscript I review some of the details within the manuscript, pointing out errors, if any, congratulating insights, if any. This was not done by either referee. There is no indication that either referee actually read the manuscript, let alone tested the hypotheses that resulted with the matrix provided.

4. The paper was about taxon exclusion. Foth and Joyce excluded taxa pertinent to the origin of turtles, which affected their basalmost taxon and the rest of their phylogram. That point was ignored by both referees who described ‘an inadequate data set’ (did they actually see the dataset, or go by rumors?). No specifics were put forth. No testing of the analysis was described. That’s what I do in such cases. I run the matrix looking for mismatches. Anyone who has the same taxon list, no matter what their character list, will come to the same results as I did, unless they omit certain pertinent taxa, as Foth and Joyce did.

5. Joyce wrote: “It is an open trade secret that David Peters has been developing an enormous phylogeny of reptiles that produces highly outlandish results.”

To that point, many results of my studies follow traditional topologies: birds nest with birds, turtles with turtles, etc. When topologies shift it is virtually always because the large size of the cladogram allows taxa that have not been tested together to be tested together. That the results upset untested traditions and paradigms are THE reason why this work should be published. The origin of turtles could have been known for the last fifty years. I just included taxa that were previously excluded.

Joyce may be upset because i pointed out this oversight, after all the hours he put into his project. That’s never welcome news, especially when that correction comes from someone without a PhD. It is potentially embarassing. Nevertheless, even if the hypotheses comes from an obscure patent clerk, this is how we build our science. The present facts should be central to the case, not any disparaging rumors about the scientist.

The data presented has to be good. Otherwise there is no way for the cladogram to have high Bootstrap scores throughout. The software is unbiased with regard to output. Unfortunately, pride, shame and other emotions are involved here when it comes to the referees. Some don’t like change.

Thank you for reading this. I don’t ask for any revision to the status of my manuscript, only that you review your policies so bias does not influence the next few incoming manuscripts.

Best regards,”