Oreopithecus, a European ape at the center of yet another bipedal debate

During the Miocene (9–7mya)
the Italian peninsula, then reduced to a series of islands, was the jungle home to long-limbed apes like Oreopithecus (Figs. 1–3; Gervais 1872, 4 feet tall). This taxon has been at the focus of a bipedal/quadrupedal argument since the 1950s. (So have pterosaurs.) 

Huerzler 1949
considered this specimen, “the earliest known representative of the line that led to man.” The hand was capable of a precision grip, convergent with human ancestors. The relatively broad pelvis (Figs. 1–3) and short jaws with small canines and other teeth of Oreopithecus were once considered diagnostic for a place in the transition to human bipedality. 

Figure 1. Oreopithecus in situ traced with colors. This fossil is imperfectly preserved and the skull is crushed like an eggshell.

Figure 1. Oreopithecus in situ traced with colors. This fossil is imperfectly preserved and the skull is crushed like an eggshell. Some bones are easy to identify. Others are best guesses.  See figure 2 for the reconstruction. This is the Hürzeler 1949 specimen.

Other workers have disputed this.
Oreopithecus was considered a jungle/swamp dweller with adaptations for hanging by its long arms from overhead branches. Gibbons have not yet been tested in the LRT, but the size and proportions appear similar.

Figure 2. Tentative reconstruction of elements traced in the Oreopithecus in situ figure 1. Other elements added from other authors.

Figure 2. Tentative reconstruction of elements traced in the Oreopithecus in situ figure 1. Other elements attributed to Oreopithecus added from other authors. Due to disarticulation and/or loss, finger and toe bones are guesswork.

While the hand and pelvis proportions
(Fig. 3) were similar to those of hominins (humans and their bipedal kin), the foot (Fig. 2, from another specimen) definitely was not. This indicates convergence, which remains rampant within the LRT.

Oreopithecus has not yet been added to the LRT.

Figure 3. From Rook et al. 1999 comparing an Oreopithecus ilium to that of Homo and Hylobates.

Figure 3. From Rook et al. 1999 comparing an Oreopithecus ilium to that of Homo and Hylobates.

Carbon isotopes
suggest a diet of “energy-rich underground tubers and corms, or even aquatic vegetation,” according to Nelson 2016. This is consistent with an arboreal yet swampy environment.

References
Gervais P 1872. Sur un singe fossile d’un espèce non ancore décrite, qui a été découvert au monte Bamboli. Comptes Rendues de l’Académie des Sciences Paris, 74: 1217-1223.
Harrison T 1990. The implications of Oreopithecus for the origins of bipedalism, in Coppens, Y; Senut, B, Origine(s) de la Bipédie chez les Hominidés [Origin(s) of Bipedalism in Hominids.
Hürzeler J 1949. Neubeschreibung von Oreopithecus bambolii Gervais.- Schweizerische Palaeontologische Abhandlungen 66(5):1–20.
Köhler M and Moya-Sola S 2003. La evolución de Oreopithecus bambolii Gervais, 1872 (Primates, Anthropoidea) y la condición de insularidad. Coloquios de Paleontología, Vol. Ext. 1 (2003) 443-458.
Nelson SV 2016. Isotopic reconstructions of habitat change surrounding the extinction of Oreopithecus, the last European ape. American Journal of Physical Anthropology 160:254–271. https://doi.org/10.1002/ajpa.22970
Rook L, Bondioli L, Köhler M, Moya-Sola S and Macchiarelli R 1999. Oreopithecus was a bipedal ape after all: Evidence from the iliac cancellous architecture. Proceeding of the National Academy of Science USA 96:8795–8799.
Russo GA and Shapiro LJ 2013. Reevaluation of the lumbosacral region of Oreopithecus bambolii. Journal of Human Evolution, published online July 23, 2013; doi: 10.1016/j.jhevol.2013.05.004

wiki/Oreopithecus

Milwaukee Journal account of the Huerzeler Oreopithecus
Smithsonian Magazine account of Oreopithecus controversies
BBC account of Oreopithecus
SciNews account of Oreopithecus

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YPM VP057103: neither Dromicosuchus nor Poposaurus

Figure 1. YPM VP 057 103 skull in situ, traced with colors using DGS methodology and reconstructed.

Figure 1. YPM VP 057 103 skull in situ, traced with colors using DGS methodology and reconstructed. Hard to tell if the postorbital is fused to the postfrontal here due to heavy cracking. The antorbital fossa identified here may instead by an elongate antorbital fenestra, as in Pseudhesperosuchus.

Identified online
by Brian Switek in 2016 on Twitter Fossil Friday as Poposaurus (Fig. 6), and published by the Yale Peabody Museum as cf. Dromicosuchus (Fig. 4) by Sterling Nesbitt 2018, specimen YPM VP 057 103 (Figs. 1–3) nests in the large reptile tree (LRT, 1342 taxa) as a member of the basal Crocodylomorpha, between incomplete Junggarsuchus and bipedal Pseudhesperosuchus.

FIgure 1. YPM VP 057 103 in situ with bones colored and reconstructed skull shown alongside.

FIgure 2. YPM VP 057 103 in situ with bones colored and reconstructed skull shown alongside.

Notable traits in the YPM specimen:
The premaxilla was elevated and pointed anteriorly forming a shark-like nose. The rostrum was elongate. The cervicals are longer than in sister taxa. The pubis curved posteriorly, as in another quadruped, Trialestes (Fig. 5). Distinct from sister taxa (and most tetrapods), the humerus was much longer than the femur in the YPM specimen. This basal crocodylomorph with long limbs and a short torso appears to have been able to gallop rapidly, something a few extant crocs are able to do.

Figure 3. YPM VP 057 103 reconstructed using color tracings from figures 1 and 2 in two scales. The smaller one shows the tail attached.

Figure 3. YPM VP 057 103 reconstructed using color tracings from figures 1 and 2 in two scales. The smaller one shows the tail attached.

The skull of the YPM specimen
does indeed remind one of Dromicosuchus (Fig. 4), but the skull of the YPM specimen all by itself can nest it with basal crocs in the LRT, 20 steps apart from Dromicosuchus.

Figure 4. Dromicosuchus makes a first appearance here at PH.WP.com. Note the similarities to the YPM specimen. Phylogenetic analysis nests the YPM specimen apart from Dromicosuchus by 20 steps.

Figure 4. Dromicosuchus makes a first appearance here at PH.WP.com. Note the similarities to the YPM specimen. Phylogenetic analysis nests the YPM specimen apart from Dromicosuchus by 20 steps.

Another long-legged, quadrupedal, basal crocodylomorph
is Trialestes (Fig. 5) which shares several traits arrived at by convergence. Note the femur remains longer than the humerus and the pubis curves posteriorly

FIgure 5. Trialestes was secondarily quadrupedl and had elongate proximal carpals, though here the radius is the smaller element, matching the diameter of the radius.

FIgure 5. Trialestes was secondarily quadrupedal and had elongate proximal carpals, though here the radius is the smaller element, matching the diameter of the radius.

Poposaurus (Fig. 6) has distinctly different proportions. Likely the identification of this specimen changed behind the scenes between 2016 and 2018. Someone should mention this to Brian Switek so he can make an edit to his Twitter account.

Figure 1. Revised skull reconstruction for the PEFO specimen. Here the anterior is considered a premaxilla. Those teeth are shaped like triangles, but they are very deeply rooted and exposed very little, which casts doubts on its hypercarnivory.

Figure 6. Revised skull reconstruction for the PEFO specimen. Here the anterior is considered a premaxilla. Those teeth are shaped like triangles, but they are very deeply rooted and exposed very little, which casts doubts on its hypercarnivory.

The YPM specimen shares many traits
and nests with Pseudhesperosuchus (Fig. 7), another basal crocodylomorph, and not far from the origin of dinosaurs.

Figue 1. A new reconstruction of the basal bipedal croc, Pseudhesperosuchus based on fossil tracings. Some original drawings pepper this image. Note the interclavicle, missing in dinosaurs and the very small ilium, only wide enough for two sacrals. The posterior dorsals are deeper than the anterior ones.

Figue 7. A new reconstruction of the basal bipedal croc, Pseudhesperosuchus based on fossil tracings. Some original drawings pepper this image. Note the interclavicle, missing in dinosaurs and the very small ilium, only wide enough for two sacrals. The posterior dorsals are deeper than the anterior ones.

References:
http://collections.peabody.yale.edu/search/Record/YPM-VP-057103

 

A small, bipedal Macrocnemus: PIMUZ T4823

It’s a bipedal, but folded specimen
with a skull and neck resting against its own spine (like Langobardisaurus).

The PMUZ T4823 specimen
of Macrocnemus (Peyer 1937; Figs. 1, 2) had such short forelimbs that it foreshadowed one of its more famous fully bipedal relatives, Sharovipteryx (Fig. 3). I even wondered if they were somehow sisters, but the LRT said, ‘no’, they were only convergent.

Figure 1. 'Macrocnemus' specimen PIMUZ T4832 in situ. Having the skull and neck bent back against the spine makes this a good problem for DGS to attempt.

Figure 1. ‘Macrocnemus’ specimen PIMUZ T4832 in situ. Having the skull and neck bent back against the spine makes this a good problem for DGS to attempt. Even colorized, this specimen still needs to be unfolded to make proper sense of its morphology and proportions. Photo from Saller 2016.

This specimen is hard to figure out
without unfolding that long neck (Fig. 2). When that happens, using DGS methods, the T4823 specimen starts to make sense. If you’re like me, sometimes the brain just needs to see things in vivo, not as if it was tucked into an eggshell.

Figure 2. 'Macrocnemus' specimen PIMUZ T4832 lifted from the in situ figure 1 at right, and unfolded at left. Not everything is guaranteed correct here, but it's pretty close. At 72 dpi screen resolution, this image is full scale.

Figure 2. ‘Macrocnemus’ specimen PIMUZ T4832 lifted from the in situ figure 1 at right, and unfolded at left. The skull is shown in situ and reconstructed. Not everything is guaranteed correct here,  The lower pelvis is a big guess because the elements may be tucked under the sacrum. At 72 dpi screen resolution, this image is full scale.

The anterior dorsal ribs of the T4832 specimen were also extra long,
perhaps creating a wide, aerodynamic, pancake-like torso, again, as in Sharovipteryx (Fig. 3) or Draco.

Note the five sacrals that helped support this sprawling lepidosaur (according to the LRT) while bipedal.

The pectoral girdle is tiny with small, disc-like coracoids. Thus, the T4832 specimen was not flapping, like Sharovipteryx (Fig. 3).

There was a soft tissue rostral crest. Soft tissue is impressed everywhere else, too.

Like Sharovipteryx, a pair of large hyoids extend neck skin, creating an aerodynamic strake or throat sac.

That is a very slender set of cervicals for such a large skull. Perhaps most of the bone was preserved below the surface. Remember, this is a cast of the destroyed original. In any case, this was a gracile specimen. If like all other Macrocnemus specimens, it had hollow bones, too.

Figure 2. Cosesaurus was experimenting with a bipedal configuration according to matching Rotodactylus tracks and a coracoid shape similar to those of flapping tetrapods. Long-legged Sharovipteryx was fully committed to a bipedal configuration.

Figure 3. Cosesaurus was experimenting with a bipedal configuration according to matching Rotodactylus tracks and a coracoid shape similar to those of flapping tetrapods. Long-legged Sharovipteryx was fully committed to a bipedal configuration.

This is not the first time
someone has suggested that Macrocnemus was facultatively bipedal. Nopcsa 1931 and Rieppel 1989 thought so, too.

This is not the first time
that a member of the Macrocnemus family became bipedal (Fig. 3). Actually most of the descendants of Macrocnemus were bipedal, whether on land or in the water.

Figure 5. Subset of the LRT focusing on the Tritosauria. Note the separation of one specimen attributed to Macrocnemus.

Figure 5. Subset of the LRT focusing on the Tritosauria. Note the separation of one specimen attributed to Macrocnemus.

Saller writes (translated by Google form Italian):
PIMUZ T4823: cast of the holotype, originally kept at the Civic Museum of Natural History of Milan (Museum Civico de Storia Naturale in Milano) was destroyed during the Second World War. Exemplary in a bad state of  conservation, described by Peyer (Peyer, 1937). Includes skull, neck, trunk, parts of the limbs and the front portion of the tail.”

Rieppel (1989) writes: 
T2473: Specimen “Besano III” (Peyer, 1937). The specimen was collected in the “Sciti bituminous” of Besano and turned over to the Museum Civico de Storia Naturale in Milano after its description by Peyer (1937),, where it was destroyed during World War II. A cast of the specimen is preserved in Zurich. The specimen is fragmentary, but includes a well-preserved hind limb.”

A renumbered specimen?
Rieppel (1989) makes no mention of PIMUZ T 4822, T4823, T4833 or T4834, but his description of the well-known specimen, A III/208. is listed first and matches this description, so it is likely renumbered in Saller 2016,

References
Li C, Zhao L-J and Wang L-T 2007A new species of Macrocnemus (Reptilia: Protorosauria) from the Middle Triassic of southwestern China and its palaeogeographical implication. Science in China D, Earth Sciences 50(11)1601-1605.
Nopcsa F 1931. Macrocnemus nicht Macrochemus. Centralblatt fur Mineralogie. Geologic und Palaeontologie; Stuttgart. 1931 Abt B 655–656.
Peyer B 1937. Die Triasfauna der Tessiner Kalkalpen XII. Macrocnemus bassanii Nopcsa. Abhandlung der Schweizerische Palaontologische Geologischen Gesellschaft pp. 1-140.
Renesto S and Avanzini M 2002. Skin remains in a juvenile Macrocnemus bassanii Nopsca (Reptilia, Prolacertiformes) from the Middle Triassic of Northern Italy. Jahrbuch Geologie und Paläontologie, Abhandlung 224(1):31-48.
Rieppel, O 1989. The Hind Limb of Macrocnemus bassanii (Nopcsa) (Reptilia, Diapsida): Deverlopment and Functional Anatomy. Journal of Vertebrate Paleontology. 9 (4): 373–387.
Romer AS 1970. Unorthodoxies in Reptilian Phylogeny. Evolution 25:103-112.
Saller F 2016. Anatomia, paleobiologia e filogenesi di Macrocnemus bassanii Nopcsa 1930 (Reptilia, Protorosauria). Alma Mater Studiorum – Università di Bologna Dottorato di Ricerca in Scienze della Terra Ciclo XXVII 206pp.

PIMUZ – Palaeontologisches Institut und Museum, University of Zuerich, Zurigo, Switzerland.

What is Rhamphocephalus? An earlier bird.

Some confusion in the academic literature today
as a Middle Jurassic fossil known since the 19th century is grossly misidentified.

Figure 2. Rhamphocephalus in situ, traced by Seeley, traced by O'Sullivan and Martill and Rhamphorhynchus graphic from Wellnhofer 1975.

Figure 1. Rhamphocephalus in situ, traced by Seeley, traced by O’Sullivan and Martill and, for comparison sake, Rhamphorhynchus graphic from Wellnhofer 1975, all appearing in O’Sullivan and Martill 2018. Rhamphocephalus has been traditionally identified as a pterosaur. That paradigm was challenged by O’Sullivan and Martill 2018, but that challenge is challenged again here.

Today a paper by O’Sullivan and Martill 2018
redescribes several fossils from the Middle Jurassic (165–166 mya) of England, traditionally ascribed to the wastebasket pterosaur taxon, Rhamphocephalus prestwichi (type, Seeley, 1880;  OUM J.28266; Figs. 1–4). Most of the disassociated specimens (individual jaws, limbs) are clearly pterosaurian. One (the goose-sized skull roof) is clearly not pterosaurian.

Figure 2. Rhamphorhynchus compared to a large choristodere, Simoedosaurus, and to a large thalattosuchian, Pelagosaurus. There is absolutely no match here.

Figure 2. O’Sullivan and Martill compared Rhamphocephalus to a large choristodere, Simoedosaurus, and to a large thalattosuchian, Pelagosaurus. There is absolutely no match here, either in size or morphology. Colors and ‘to scale’ Rhamphocephalus images added for clarity.

The holotype of Rhamphocephalus prestwichi,
“an isolated skull table, is found to be a misidentified crocodylomorph skull,” according to O’Sullivan and Martill, who illustrated the 10x smaller specimen alongside a dorsal view of the 3m long thalattosuchian (marine) croc, Pelagosaurus, from the Lower Jurassic of England and, perhaps to cover all their bases, flipped anterior-to-posterior alongside the Paleocene choristodere, Simoedosaurus (Fig. 2). Note: the authors did not illustrate their comparative taxa to scale (as shown above), perhaps because the taxa are 10x larger and are morphologically dissimilar. So why make such comparisons? I don’t understand the logic of these paleontologists making such readily disprovable comparisons.

Figure 1. The skull roof named Rhamphocephalus here with bones and teeth colored.

Figure 3. The in situ specimen of Rhamphocephalus here with bones and teeth colored. At standard monitor 72 dpi resolution, this image is 2x life size. Perhaps this skull can be µCT scanned for buried data. Some palatal elements are peeking out from the antorbital fenesrae and nares. The dentary teeth make a few appearances, too. This is a sharp-tipped taxon.

Traced here
using DGS methods (Fig. 3) and phylogenetically tested in the large reptile tree (LRT, 1321 taxa) goose-sized Rhamphocephalus nests with the hummingbird-sized, Hongshanornis (Fig. 2), an Early Cretaceous toothed bird from China. Hongshanornis is one of the few toothed birds in which the orbits are further forword, creating a longer cranium to match that of Rhamphocephalus. A suite of other skull traits are likewise most closely matched to Hongshanornis. The Rhamphocephlaus specimen appears to be complete without obvious breaks either at the toothy tip of the skull or the occiput. More teeth and bones were identified here.

Figure 2. Rhamphorcephalus in situ compared to Hongshanornis in situ to scale and enlarged to match.

Figure 2. Rhamphorcephalus in situ compared to Hongshanornis in situ to scale and enlarged to match skull length. To scale image (above) is 1.25x actual size, much too small for sea crocs. similar in size to pre-birds. Hongshanornis is a tiny bird, similar in size to a hummingbird.

Ironically
the authors report, “The earliest known record of Bathonian pterosaurs is an account of “fossil bird bones” from the Taynton Limestone Formation of Stonesfield by an anonymous author A.B., appearing in the March edition of the Gentleman’s Magazine of 1757.” For this specimen, and only this specimen, A.B. got it right. The other specimens are clearly pterosaurian.

Historically
the authors report, “This specimen is exposed on a limestone slab in dorsal view and was assigned to Pterosauria based on its perceived thin bone walls. Seeley (1880) noted that the arrangement of bones was more crocodilian than pterosaurian and considered this construction diagnostic of the new taxon. Significantly he (Seeley 1880: 30) stated: “I shall be quite prepared to find that all the ornithosaurians from Stonesfield belong to this or an allied genus which had Rhamphorhynchus for its nearest ally.” In the LRT crocodilians are closer to birds than pterosaurs are.

Figure 6. Rhamphocephalus chronologically precedes the Solnhofenbirds by several million years making it the oldest known bird.

Figure 6. Rhamphocephalus chronologically precedes the Solnhofenbirds by several million years making it the oldest known euornithine bird.

Is the Middle Jurassic too early for a toothed bird?
Perhaps not. Remembet that all of the Late Jurassic Solnhofen birds, traditionally named as one genus, Archaeopteryx, already represent a diverse radiation of taxa, suggesting an earlier genesis for that radiation. Rhamphocephalus indicates that the original bird radiation had its genesis at least 15 million years earlier. 

It is unfortunate
that O’Sullivan and Martill attempted to force fit the skull specimen into a crocodilian clade when no aspect of the thin-walled, goose-sized skull of Rhamphocephalus is crocodilian (Fig. 2)… or choristoderan (when flipped backwards!!). Adding Rhamphocephalus to the LRT gives it a single most parsimonious sister among all the toothed birds and a special Middle Jurassic place in the origin of birds story. All the details fit.

Working with a high-resolution image
of Rhamphocephalus (Fig. 3) copied from a PDF of the paper by O’Sullivan and Martill made this all possible.

Once again, to determine the affinities of a specimen it is more important to have a wide gamut of taxa to work with than to have firsthand access to the specimen itself. No one likes this method, but it clearly works time after time and to not use it invites discredit.

USE THE LRT. That’s what it is here for.

References
O’Sullivan M and Martill DM 2018. Pterosauria of the Great Oolite Group (Bathonian, Middle Jurassic) of Oxfordshire and Gloucestire. Acta Palaeontologica Polonica 63 (X): xxx–xxx, 2018 https://doi.org/10.4202/app.00490.2018
Seeley HG 1880. On Rhamphocephalus prestwichi Seeley, an Ornithosaurian from the Stonesfield Slate of Kineton. Quart. J. Geol. Soc. 36: 27-30.

wiki/Rhamphocephalus

Scaphognathus wing membrane in visible light

Today a paper by Jäger et al. 1831
put the holotype of Scaphognathus (Goldfuß 1831; Late Jurassic) under various forms of illumination and re-discovered soft tissue originally noted and rarely cited.

Figure 1. Holotype of Scaphognathus GIF animation showing extent of wing membrane ignored by xx et al. 2018.

Figure 1. Holotype of Scaphognathus GIF animation showing extent of wing membrane ignored by xx et al. 2018.

Ironically
the authors ignored the most obvious aspect of the Scaphognathus soft tissue: the presence of a narrow chord wing membrane (Fig. 1), as documented by Peters (2002) and ignored ever since, per Chris Bennett’s threat, “You won’t get published, and if you do get published, you won’t get cited.”

Figure 2. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Now compare this figure with figure 3, which shows the wings and uropatagia unfolding. There is no way to turn this into a deep chord wing membrane. And it decouples the forelimbs from the hind limbs.

Figure 2. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Now compare this figure with figure 3, which shows the wings and uropatagia unfolding. There is no way to turn this into a deep chord wing membrane. And it decouples the forelimbs from the hind limbs.

The Vienna specimen of Pterodactylus
(Figs. 2, 3) are the prime examples of a narrow chord wing membrane, stretched between the wing tip and elbow… as in all pterosaurs that preserve soft tissue.

The Vienna Pterodactylus.

Figure 3. The Vienna Pterodactylus. Click to animate. Wing membranes in situ (when folded) then animated to extend them. There is no shrinkage here or in ANY pterosaur wing membrane. There is only an “explanation” to avoid dealing with the hard evidence here and elsewhere.

There are still no examples
of a deep chord wing membrane (attached to the ankle or tibia) preserved in any pterosaurs, as documented here, here, here and here.

References
Goldfuß A 1831. Beiträge zur Kenntnis verschiedener Reptilien der Vorwelt. Nova Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum, 15:61-128.
KRK Jäger, Tischlinger H, Oleschinski G, and Sander PM 2018. Goldfuß was right: Soft part preservation in the Late Jurassic pterosaur Scaphognathus crassirostris revealed by reflectance transformation imaging (RTI) and UV light and the auspicious beginnings of paleo-art. Palaeontologia Electronica 21.3.4T: 1-20. pdf
Peters D 2002. A new model for the evolution of the pterosaur wing – with a twist. Historical Biology 15: 277–301.

Misinterpreting Zhongornis

A few years ago
O’Connor and Sullivan 2014 took another look at a small bird-like theropod, Zhongornis, originally identified as a bird. They thought they saw “striking resemblances to both Oviraptorosauria and Scansoriopterygidae.” According to Wikipedia, “The authors reinterpreted Zhongornis as the sister taxon of scansoriopterygids, and further suggested that this clade (Zhongornis + Scansoriopterygidae) is the sister group of Oviraptorosauria.”

The original paper by Gao, et al. 2008
(O’Connor was a co-author) considered Zhongornis a bird, “the sister group to all pygostylia,” which is an invalid clade in the LRT. Several disparate clades developed pygostyles in the LRT.

Figure 4. Confuciusornithiformes to scale. Note the lack of a pygostyle in the majority of taxa.

Figure 4. Confuciusornithiformes to scale. Note the lack of a pygostyle in the majority of taxa.

By adding more relevant taxa,
in the large reptile tree (LRT, 1315 taxa) Zhongornis nested between Archaeopteryx (= Wellnhoferia) grandis and Confusciusornis (Fig. 1). Scansoriopterygids, in the LRT, are descendants of the Solnhofen bird, ‘Archaeopteryx‘ #12.

Figure 2. Zhongornis in situ.

Figure 2. Zhongornis in situ, skull reconstructiion, pes, manus and tail.

Zhongornis haoae (Gao et al. 2008; D2455; Early Cretaceous). Lack of fusion and bone texture indicate the Zhongornis holotype is a juvenile. The femoral heads and necks are not visible, perhaps not yet ossified. Even so, the wing feathers are well-develped, so the specimen is not a hatchling, but close to fledging, according to Gao et al.

Figure 3. Zhongornis pectorals as traced here and as traced by O'Connor and Sullivan (right).

Figure 3. Zhongornis pectorals as traced here and as traced by O’Connor and Sullivan (right).

The problem with the O’Connor and Sullivan paper was…
taxon exclusion. They did not test all Solnhofen birds, but considered them all Archaeopteryx and selected one to test. They did not realize that various Solnhofen birds are basal to ALL later bird clades, even those that gave up flying and grew to large to fly.

Figure 4. Zhongornis pelvic and tail area as traced here and as traced by O'Connor and Sullivan.

Figure 4. Zhongornis pelvic and tail area as traced here and as traced by O’Connor and Sullivan. The red bones are pubes. The green ones are ilia or impressions thereof.

We talk about elongate coracoids
when we talk about birds (Aves).

O’Connor and Sullivan 2014 report, “The coracoid is not well-preserved and is largely overlapped by other elements, making it difficult to confirm the original description (Gao et al., 2008) of this bone as strut-like; in DNHM D2456 it appears short, robust, and trapezoidal, a primitive morphology that characterizes oviraptorosaurs and scansoriopterygids, as well as dromaeosaurids, troodontids, Archaeopteryx and sapeornithiforms.”

In contrast
Zhongornis clearly has two elongate, barbell-shaped coracoids (Fig. 3), as in Confuciusornis.

In ReptileEvolution.com the coracoids of scansoriopterygids and Archaeopteryx have elongate coracoids. By contrast, Sapeornis and other sapeornithiforms have relatively short coracoids, reduced along with the forelimbs as the body size increased. This is sometimes called a reversal. Short coracoids can also be found in extant flightless birds.

Don’t judge or nest a taxon on just a few or a few dozen traits.
Always let the unbiased software place the taxon. To put limits on your taxon list.

References
Gao C-L, Chiappe LM, Meng Q-J, O’Connor JK, Wang X, Cheng X-D and Liu J-Y 2008. A new basal lineage of early Cretaceous birds from China and its implications on the evolution of the avian tail. Palaeontology 51(4):775-791.
O’Connor J-M and Sulivan C 2014.
Reinterpretation of the Early Cretaceous maniraptoran (Dinosauria: Theropoda) Zhongornis haoae as a scansoriopterygid-like non-avian, and morphological resemblances between scansoriopterygids and basal oviraptorosaurs. Vertebrata PalAsiatica 52(1)1–9.

wiki/Changchengornis
wiki/Confuciusornis
wiki/Zhongornis

SVP 2018: Cassowary casque development

You heard it here first.

Ontogenic studies by Green and Gignac 2018 report
cassowaries (genus: Casuarius, Fig. 1) develop their casque as “a midline chondrocranial element [the mesethmoid, that] grows relatively slowly and posteriad to buttresses lateral dermatocranial bones.” 

Figure 2. The cassowary skull shows the mesethmoid (yellow green) is greatly expanded from its original flat appearance in Rhea.

Figure 2. The cassowary skull shows the mesethmoid (yellow green) is greatly expanded from its original flat appearance in Rhea.

Green and Gignac 2018 conclude,
These findings suggest that cassowaries are an outlier among dinosaurs, making them poor models for cranial developmental and evolution studies outside of Palaeognathae.”

References
Green TL and Gignac PM 2018. Testing the utility of cassowaries as living models for non avian dinosaur cranial elements. SVP abstracts.