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 3. Subset of the LRT focusing on theropods leading to birds, including the two newest additions, Bambiraptor and Zanabazar.

Figure 3. Subset of the LRT focusing on theropods leading to birds, including the two newest additions, Bambiraptor and Zanabazar.

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 fossils 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.
More data added August 14, 2020.
Figure 2020.1. Skeleton of Halszkarpator revised to permit the cervicals to connect at the back of the skull where the occiput is.

Figure 2020.1. Skeleton of Halszkarpator revised to permit the cervicals to connect at the back of the skull where the occiput is.

Figure 2020.2 Skull of Halszkaraptor in situ.

Figure 2020.2 Skull of Halszkaraptor in situ.

Figure 2020.3. µCT scans of Halszkaraptor reconstructed slightly. Note some bone colors are changed here.

Figure 2020.3. µCT scans of Halszkaraptor reconstructed slightly. Note some bone colors are changed here.

Another post on Halszkaraptor from several years back
has been trashed following the correction made to the premaxilla/maxilla suture seen here (Fig. 2020.3). My mistake. All sisters have a shorter premaxilla with fewer teeth. However, that is not the pattern in Halszkaraptor, which has a longer premaxilla extending further beyond the naris. That change did not change the tree topology.


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

Fukuivenator: not a mystery, the basalmost tyrannosaur!

Updated February 28, 2016 with new restorations of Fukuivenator and Tianyuraptor and shifting Fukuivenator one node more primitive. 

Fukuivenator paradoxus 
(Azuma et al. 2016, FPDM-V8461, Fig. 1), was originally described as, “a bizarre theropod.” With a specific name like “F. paradoxus,” it’s easy to see there was mystery surrounding this theropod.

Unfortunately, this may just be a case
of taxon exclusion and a sour matrix. No reconstructions were published and several scale bars do not appear to be valid. I had no trouble nesting this theropod. Rather than bizarre, it shares a long list of traits with its new sisters (Figs. 2, 3).

Figure 1. Fukvenator parts to scale lifted from Azuma et al. 2016. Note, the larger skull, hind limb and foot match Zhenyuanlong in size and general morphology. Only the manus is relatively larger. I suspect the smaller skull scale bar.

Figure 1. Fukvenator parts to scale lifted from Azuma et al. 2016. Note, the larger skull, hind limb and foot match Zhenyuanlong in size and general morphology. Only the manus is relatively larger. I suspect the smaller skull scale bar.

From the abstract:
“While Fukuivenator possesses a large number of morphological features unknown in any other theropod, it has a combination of primitive and derived features seen in different theropod subgroups, notably dromaeosaurid dinosaurs.” 

From the Diagnosis
A relatively small theropod with the following unique features (comments follow):

  1. unusually large external naris (slightly smaller than antorbital fenestra in dorsoventral height) – also in Ornitholestes and Tianyuraptor (O&T)
  2. large premaxillary fenestra subequal in size to maxillary fenestra – also in Zhenyuanlong (Z)
  3. large oval lacrimal pneumatic recess posterodorsal to the maxillary fenestra on antorbital fossa medial wall – also in the tyrannosaur clade
  4. lacrimal with a distinct groove on lateral surface of anterior process and a ridge on lateral surface of descending process – detail too small to see
  5. postorbital frontal process with T-shaped-cross section and laterally-flanged squamosal process – also in the tyrannosaur clade
  6. an elongate tubercle on posterior surface of basal tuber of the basicranial region – detail too small to see
  7. highly heterodont dentition featuring robust unserrated teeth including small spatulate anterior teeth, large and posteriorly curved middle teeth, and small and nearly symmetrical posterior teeth  – also in the tyrannosaur clade
  8. cervical vertebrae with a complex lamina system surrounding the neural canal resulting in deep and wide grooves for interspinous ligaments and additional deep sockets  – also in the tyrannosaur clade
  9. anterior cervical vertebrae with interprezygapophyseal, postzygadiapophyseal, prezygadiapohyseal, and interpostzygapophyseal laminae connecting to each other to form an extensive platform  – also in the tyrannosaur clade
  10. anterior and middle cervical vertebrae with transversely bifid neural spines  – also in the tyrannosaur clade
  11. dorsal, sacral, and anterior caudal vertebrae with strongly laterally curved hyposphene and centropostzygapophyseal laminae that, together with the postzygapophyseal facet, form a socket-like structure for receiving the prezygapophysis – unfamiliar with this
  12. dorsoventrally bifurcated sacral ribs – also in Zhenyuanlong (Z)
  13. caudal zygapophyseal facets expanded to be substantially wider than the zygapophyseal processes;– unfamiliar with this and
  14. middle caudal vertebrae with transversely and distally bifid prezygapophyses.– unfamiliar with this
Figure 2. Ornitholestes, Tianyuraptor and Zhenyuanlong are close relatives of Fukuivenator at the base of the tyrannosaur clade. Gray zone on Ornitholestes skull marks off the boundary of the external naris.

Figure 2. Ornitholestes, Tianyuraptor and Zhenyuanlong are close relatives of Fukuivenator at the base of the tyrannosaur clade. Gray zone on Ornitholestes skull marks off the boundary of the external naris.

Nowhere in the text
do the authors list Zhenyuanlong, but Tianyuraptor is listed.The large reptile tree (subset fig. 3) nests Fukuivenator at the base of the tyrannosaurs between Tianyuraptor and Ornitholestes. One tree published by Azuma et al. also nests Fukuivenator with Ornitholestes, but it has many other problems and lacks resolution at several nodes. So here we have a tentative agreement with the published work.

Like Ornitholestes and Tianyuraptor
Fukuivenator has an enormous round naris (“all the better to smell you with, my dear~”)

Like Zhenyuanlong and T-rex
Fukuivenator has a taller than wide orbit and deeply rooted teeth. Premaxillary teeth are incisor (‘D’) -shaped.

Like Ornitholestes
The skull is shorter than the cervical series and shorter than half the presacral length.

Figure 2. Fukuiraptor nests with basal tyrannosaurs in the theropod subset of the large reptile tree.

Figure 2. Fukuivenator nests with basal tyrannosaurs in the theropod subset of the large reptile tree.

The authors note several dromaeosaurid traits
but Fukuivenator does not have a large killer claw. Fukuivenator actually provides more evidence that basal tyrannosaurs were dromaeosaur mimics, with large wing feathers and stiff tails, just like Microraptor, the bird mimic. Instead of being sharp-eyed predators, as we presume the deinonychosaurs, troodontids and birds were/are, some basal tyrannosaur clade members may have used their nose. So this is where T-rex became “a stellar smeller” back in the Late Jurassic/Early Cretaceous.

Not sure why professional paleontologists
are not seeing these relationships, but I think I smell a sour matrix over there that, like an old sock, has been used to many times without running it through the washer every so often.

As in pterosaurs and turtles and Vancleavea and caseids and mesosaurs…
if you can’t find a good sister taxon among the traditional sister taxa, then maybe you need to look elsewhere. In this case, Fukuivenator does not nest with dromaeosaurs, but very nicely with basalmost tyrannosaurs without paradox or bizarre qualities. I note this, as usual, without seeing the fossil firsthand, for which I am often vilified. This study shows that contributions can be done in paleontology without seeing the fossils firsthand.

References
Azuma Y, Xu X, Shibata1 M, Kawabe S, Miyata K and Imai T 2016. A bizarre theropod from the Early Cretaceous of Japan highlighting mosaic evolution among coelurosaurians. Nature Scientific Reports | 6:20478 | DOI: 10.1038/srep20478

What?? No feathers on velociraptors?

Figure 1. Inside cover illustration spread for "Raptors, the Nastiest Dinosaurs" by Don Lessem, illustrated by David Peters. Don asked for a "no feathers dinosaur" so that's what he got. Don't blame the artist. I tried to persuade. Utahraptor is the big dromaeosaur here.

Figure 1. Inside cover illustration spread for “Raptors, the Nastiest Dinosaurs” by Don Lessem (1996), illustrated by yours truly, David Peters. Don asked for a “no feathers dinosaur” so that’s what he got. Don’t blame the artist. I tried to dissuade. Utahraptor is the big dromaeosaur here.

This post was inspired
by a blog and Flickerstream I ran across here and here that bemoaned the fact that my 1996 dromaeosaurids / velociraptors (Fig. 1) in “Raptors – The Nastiest Dinosaurs” did not have feathers, but did have propatagia.

Guys, I tried to add feathers, as I had done several years earlier (1989) to my own velociraptors in Gallery of Dinosaurs (Fig. 2). However, author Don Lessem insisted that no feathers appear in his book. I tried to dissuade, but was vetoed. After all, he is the author. And that was then. I’m sure Dino Don has come around to new thinking since then.

See how difficult it is to promote a new idea supported by data? Even an expert like Don Lessem balked back in 1995-6.

Figure 2. Feathered Deinonychus from A Gallery of Dinosaurs by David Peters.

Figure 2. Feathered Deinonychus from A Gallery of Dinosaurs by yours truly, David Peters. (1989). Click to enlarge.

So, there is a backstory,
as there is with other controversial aspects of my work. At present the backstory and trashed ideas are not as important as the current work. Science marches on and new data keeps coming in. So let’s stay with the current wave. If you see any other problems with my  tracings or identifications, please let me know of those issues.

References
These are kids books, not academic journals!
“A Gallery of Dinosaurs” is online here.