The strange skull of the violet turaco (genus: Macrophaga violate)

Figure 1. The violet turaco (genus: Musophaga) with its skull and a related skeleton.

Figure 1. The violet turaco (genus: Musophaga) with its skull and a related skeleton. Note the expanded nasals rimmed by prefrontals. The spectacular color and jungle habitat are clues that turacos are in the same family as birds of paradise.

Musophaga violacea (Isert 1788; 48 cm long) is the extant violet turaco, originally considered a near-passerine. Here it nests with the trumpeter (genus: Psophia, Fig. 2). In Musophaga the legs and sternum are shorter. The pelvis is deeper and the tail is more robust.

Figure 3. Psophia the trumpeter in vivo and skeleton.

Figure 2. Psophia the trumpeter in vivo and skeleton.

References
Isert 1788. Kurze Beschreibung und Abbildung einiger Vögel aus Guinea. – Schriften der Berlinischen Gesellschaft Naturforschender Freunde 9: 16-20

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A slight adjustment to an OMNH Cotylorhynchus reconstruction

The AMNH specimen
of Cotylorhynchus is a spectacular sight to see (Fig. 1). It’s huge! And complete! It’s bigger than a Galápagos tortoise with a skull just as small.

Figure 1. Cotylorhynchus AMNH specimen. Note the angle of the ribs.

Figure 1. Cotylorhynchus AMNH specimen. Note the angle of the ribs. Is that a whip-lash tail? Compare to Datheosaurus (Fig. 4). Just look at those massive elbows!

Romer and Price 1940
pictured Cotylorhynchus with vertical dorsal ribs (Fig. 2 lateral view).

Cotylorhynchus romeri

Figure 2. Cotylorhynchus romeri

The Sam Noble Museum Oklahoma’s Museum of Natural History
in Norman, Oklahoma, USA, has a mount of Cotylorhynchus (Fig. 3) that follows the Romer and Price illustration with vertical ribs. Here, in this 2-frame GIF animation, I have angled them back to match the in situ specimen and most other quadrupedal tetrapods.

Figure 3. Cotylorhynchus mount in the Sam Noble Museum of Natural History with vertical ribs modified here to have diagonal ribs more typical of tetrapods and reflective of the in situ fossil.

Figure 3. Cotylorhynchus mount in the Sam Noble Museum of Natural History with vertical ribs modified here to have diagonal ribs more typical of tetrapods and reflective of the in situ fossil.

Cotylorhynhcus romeri (Stovall 1937) Kungurian, Middle Permian, ~265 mya, ~6 m in length, was the largest sister to Casea and Ennatosaurus. It was the largest land animal of its time.

Figure 2. Milleretta, caseasaurs and kin. The LRT nests these taxa together apart from the Synapsida, with which they share a lateral temporal fenestra.

Figure 4. Milleretta, caseasaurs and kin. The LRT nests these taxa together apart from the Synapsida, with which they share a lateral temporal fenestra. Note the angle of the ribs in the Milleretta reconstruction, similar to the suggestion for Cotylorhynchus. Casea and Ennatosaurus continue to have invalid vertical ribs in the above figure due to my laziness.

All prior and other current reports
nest Cotylorhynchus with the synapsid pelycosaurs, but here in the large reptile tree (LRT. 1315 taxa) the caseid clade nests more parsimoniously with Milleretta, Feeserpeton and Australothyris and other plant-eaters, many of which share a lateral temporal fenestra in the new Lepidosauromorpha, opposite to the coeval pelycosaurs nesting in the new Archosauromorpha.

We looked at this traditional mistake
based on taxon exclusion here back in 2011. Even so, synapsid workers continue to follow this outdated tradition without testing validated alternatives proposed here.

References
Romer AS and Price LI 1940. Review of the Pelycosauria. Geological Society of America Special Papers 28: 1-538.
Stovall JW 1937. Cotylorhynchus romeri, a new genus and species of pelycosaurian reptile from Oklahoma. Arnerican Journal of Science (5) 34: 308-313.
Stovall JW, Price LI and Romer AS 1966. The Postcranial Skeleton of the Giant Permian Pelycosaur Cotylorhynchus romeri. Bulletin of the Museum of Comparative Zoology 135 (1): 1-30. online pdf

wiki/Cotylorhynchus

Aceratherium vs. Paraceratherium

Aceratherium is a hornless rhino (Figs 2-4).
Paraceratherium is a GIANT hornless horse (Fig. 1). Even so, the two are similar enough that that latter was named for the former. Thereafter Paraceratherium became known as a rhino.

Figure 1. Equus the horse shares many traits with Paraceratherium, the giant rhino/horse.

Figure 1. Equus the horse shares many traits with Paraceratherium, the giant three-toed horse.

However,
and as we learned earlier by testing prior assumptions in the large reptile tree (LRT, 1318 taxa, subset Fig. 5), Aceratherium nested between rhinos and brontotheres. Paraceratherium nested with other large three-toed horses.

Fig. 1. Aceratherium skeletal mount. This hornless rhino is transitional to brontotheres, not indricotheres (= paraceratheres).

Fig. 2 Aceratherium skeletal mount. This hornless rhino is transitional to brontotheres, not indricotheres (= paraceratheres) in the LRT.

Even so,
the convergence is impressive! No wonder earlier workers named the one for the other.

Figure 2. Aceratherium acutum skull drawing and fossil.

Figure 3. Aceratherium acutum skull drawing and fossil.

Convergence is rampant within the LRT.
For example, we’ve seen mysticetes and odontocetes converge so much we call them all ‘whales’ or ‘cetaceans‘, two terms that need to be dumped in favor of something more in keeping with their phylogenetic nestings. The same has happened with Aceratherium and Paraceratherium. The details of their skeletal traits distinguish them. You can examine those traits in a MacClade file by request.

Figure 1. Indricothere skulls to scale along with horse and rhino skulls.

Figure 4. Indricothere skulls to scale along with horse and rhino skulls.

Perhaps this is just one more instance of paleontology
turning a blind eye toward testing a wider gamut of taxa to validate prior hypotheses… or invalidate them. That’s why the LRT is here: to test prior hypotheses.

Figure 5. Various ungulates and kin subset of the LRT. Here Aceratherium, a hornless rhino, does not nest with Paraceratherium, a giant three-toed horse.

Figure 5. Various ungulates and kin subset of the LRT. Here Aceratherium, a hornless rhino, does not nest with Paraceratherium, a giant three-toed horse.

Shifting all the paraceratheres
over to the aceratheres adds 21 steps to the LRT.

Aceratherium incisivum (Kaup 1832; originally Rhinoceros incisivum, Cuvier 1822; Miocene; 2.3m long) nests with short-legged Metamynodon and shares with it long anterior dentary teeth, a straight jugal and a short nasal. Aceratherium lacks an upper canine.

Figure 2. GIF movie (3 frames) showing what is known of the skeletons of Baluchitherium and Indricotherium. Note the more horse-like morphology.

Figure 6. GIF movie (3 frames) showing what is known of the skeletons of Baluchitherium and Indricotherium. Note the more horse-like morphology.

Paraceratherium transouralicum  (P. bugtiense holotype, Pilgrim 1908; Baluchitherium, Osborn 1923; late Oligocene, 34-23mya; 4.8m shoulder height, 7.4m long) was long considered a giant hornless rhinoceros, but here nests with the horse, Equus. They share a long neck, straight ventral dentary and the retention of premaxillary teeth, among other traits. Paraceratherium retains three toes, as in ancestral horse/rhinos like Heptodon and Hyracotherium.

Figure 3. In the LRT Mesohippus nests basal to horses and indricotheres.

Figure 7. Mesohippus, the last common ancestor in the LRT to horses and indricotheres.

References
Chow M and Chiu C-S 1964. An Eocene giant rhinoceros. Vertebrata Palasiatica, 1964 (8): 264–268.
Cuvier G 1822a. Recherches sur les ossements fossiles. Tome second, G. Doufor et d’Ocagne éd., Paris, – (1822b). Tome troisième, – (1824). Tome cinquième.
Forster-Cooper C 1911. LXXVIII.—Paraceratherium bugtiense, a new genus of Rhinocerotidae from the Bugti Hills of Baluchistan.—Preliminary notice. Annals and Magazine of Natural History Series 8. 8 (48): 711–716. doi
Forster-Cooper C 1924. On the skull and dentition of Paraceratherium bugtiense: A genus of aberrant rhinoceroses from the Lower Miocene Deposits of Dera Bugti. Philosophical Transactions of the Royal Society B: Biological Sciences. 212 (391–401): 369–394.
Granger W and Gregory WK 1935. A revised restoration of the skeleton of Baluchitherium, gigantic fossil rhinoceros of Central Asia. American Museum Novitates. 787: 1–3.
Kaup J 1832. Über Rhinoceros incisivus Cuv., und eine neue Art, Rhinoceros schleier-macheri, Isis von Oken, Jahrgang1832 (8: 898-904.
Lucas SG and Sobus JC 1989. The Systematics of Indricotheres”. In Prothero DR and Schoch RM eds. The Evolution of Perissodactyls. New York, New York & Oxford, England: Oxford University Press: 358–378. ISBN 978-0-19-506039-3.
Osborn HF 1923. Baluchitherium grangeri, a giant hornless rhinoceros from Mongolia. American Museum Novitates. 78: 1–15. PDF
Pilgrim GE 1910. Notices of new mammalian genera and species from the Tertiaries of India. Records of the Geological Survey of India. 40 (1): 63–71.
Wood HE 1963. A primitive rhinoceros from the Late Eocene of Mongolia. American Museum Novitates 2146:1-11.

wiki/Juxia
wiki/Paraceratherium
wki/Indricotheriinae
wiki/Metamynodon
wiki/Aceratherium

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.

Dorsetisaurus: a Mesozoic tegu, not an anguimorph

Known from the Early Cretaceous of Mongolia
and the Late Jurassic of Portugal, Dorsetisaurus purbeckensis (BMNH R.8129, skull width: 1.4cm; Hoffstetter 1967; Fig. 1) was attributed to the clade of glass lizards (Anguimorpha) originally and in two later papers. Evans 2006 nested it between the highly derived legless skink, Amphisbaenia, and the basal gecko (in the LRT), Chometokadmon (which Evans considered an anguimorph).

FIgure 1. Dorsetisaurus bits and pieces restored here and scored nests in the LRT with Tupinambis, the extant tegu.

FIgure 1. Dorsetisaurus bits and pieces restored here and scored nests in the LRT with Tupinambis, the extant tegu.

By contrast
in the large reptile tree (LRT, 1318 taxa) Dorsetisaurus nests with the basal scerloglossan, lacertoid, teiid, Tupinambis (Fig. 2), the extant tegu lizard. Even the slight notch in the ventral maxilla is retained over 120 million years of evolution.

Figure 2. Tupinambis is the extant tegu lizard, a sister to Dorseitsaurus in the LRT.

Figure 2. Tupinambis is the extant tegu lizard, a sister to Dorseitsaurus in the LRT.

On a side note:

Gauthier et al. 2012 put together two squamate trees of life, one based on traits, another based on genes. Neither matches the LRT, which includes more fossil taxa.

References
Evans SE, Raia P, Barbera C 2006. The Lower Cretaceous lizard genus Chometokadmon from Italy. Cretaceous Research 27:673-683.
Gauthier, JA, et al. 2012. Assembling the squamate tree of life: Perspectives from the phenotype and the fossil record. Bulletin of the Peabody Museum of Natural History 53.1 (2012): 3-308.
Hoffstetter  R 1967.
Coup d’oeil sur les Sauriens (lacertiliens) des couches de Purbeck (Jurassique supérieur d’Angleterre Résumé d’un Mémoire). Colloques Internationaux du Centre National de la Recherche Scientifique 163:349-371.

wiki/Dorsetisaurus
http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=38022

A reexamination of Milosaurus: Brocklehurst and Fröbisch 2018

I just found out that not one but two Aerosaurus specimens were tested and are to be found in the SuppData for this paper. So, what happened here? I’ll dig deeper to look for a solution. 

Brocklehurst and Fröbisch 2018 reexamine
“a large, pelycosaurian-grade synapsid” not from the Early Permian, but from the Latest Carboniferous of Illinois Milosaurus (Fig. 1) was first described by DeMar 1970 as a member of the Varanopsidae (= Varanopidae). Brocklehurst and Fröbisch note, “Milosaurus itself has received little attention since its original description. The only attempt to update its taxonomic status was by Spindler et al. (2018). These authors included Milosaurus in a phylogenetic analysis that, although principally focused on varanopids, contained a small sample of pelycosaurs from other families. Milosaurus was found nested within Ophiacodontidae, as the sister to Varanosaurus.”

Ultimately
Brocklehurst and Fröbisch nested Milosaurus with Haptodus within the Eupelycosauria.

Figure 1. The pes of Milosaurus in situ, reconstructed and compared to Aerosaurus, its sister in the LRT.

Figure 1. The pes of Milosaurus (FMNH PR 701) in situ, reconstructed and compared to Aerosaurus, its smaller sister in the LRT. PILs added to restore distal phalanges.

By contrast
the large reptile tree nested Milosaurus with Aerosaurus (Fig. 1; Romer 1937, A. wellesi Langston and Reisz 1981), a taxon not listed by Brocklehurst and Fröbisch. Based on the pes alone, Milosaurus was twice the size of Aerosaurus. Aerosaurus is a basal synapsid more primitive than Haptodus and the Pelycosauria. Aerosaurus and Milosaurus nest between Elliotsmithia + Apsisaurus and Varanops.

Unfortunately
Brocklehurst and Fröbisch included the unrelated clade Caseasauria in their study of Synapsida, and did not include Aerosaurus. They also include Pyozia, not realizing it is a proto-diapsid derived from and distinct from varanopid synapsids. So, once again, taxon exclusion and inappropriate taxon inclusion are the reasons for this phylogenetic misfit.

Distinct from Haptodus, and similar to Aerosaurus
in Milosaurus metatarsals 2 and 3 align with p1.1, not mt1. The base of mt 5 is quite broad. Other traits also attract Milosaurus to Aerosaurus, including an unfused pubis + ilium. I was surprised that so few traits nested Milosaurus in the LRT as it continues to lump and split taxa with the current flawed list of multi-stage characters.

References
Brocklehurst N and Fröbisch J 2018. A reexamination of Milosaurus mccordi, and the evolution of large body size in Carboniferous synapsids. Journal of Vertebrate
Paleontology, DOI: 10.1080/02724634.2018.1508026
DeMar R. 1970. A primitive pelycosaur from the Pennsylvanian of Illinois. Journal of Paleontology 44:154–163.
Langston W Jr and Reisz RR 1981. Aerosaurus wellesi, new species, a varanopseid mammal-like reptile (Synapsida: Pelycosauria) from the Lower Permian of New Mexico. Journal of Vertebrate Paleontology 1:73–96.
Romer AS 1937. New genera and species of pelycosaurian reptiles. Proceedings of the New England Zoological Club 16:90-96.

wiki/Aerosaurus