What is the enigmatic Otter Sandstone (Middle Triassic) diapsid?

Coram, Radley and Benton 2017
presented a “small diapsid reptile [BRSUG 29950-12], possibly, pending systematic study, a basal lepidosaur or a protorosaurian.” According to Coram et al. “The Middle Triassic (Anisian) Otter Sandstone was laid down mostly by braided rivers in a desert environment.”

Figure 1. The Middle Triassic Otter Sandstone diapsid BRSUG 29950-12 under DGS nested with basalmost lepidosaurs like Megachirella.

Figure 1. The Middle Triassic Otter Sandstone diapsid BRSUG 29950-12 under DGS nested with basalmost lepidosaurs like Megachirella. Skeleton is exposed in ventral (palatal) view.

The LRT is here to nest and identify published enigmas
The large reptile tree (LRT 1041 taxa) nests BRSUG 29950-12 with the basalmost lepidosaur Megachirella. They are a close match and preserve nearly identical portions of their skeletons (Fig. 2). Megachirella was originally considered a sister to Marmoretta, another basal sphenodontian from the much later Middle/Late Jurassic.

FIgure 2. Megachirella (Renesto and Posenato 2003) is a sister to the BSRUG diapsid.

FIgure 2. Megachirella (Renesto and Posenato 2003), also from Middle Triassic desposits, is a sister to the BSRUG diapsid and provides a good guide for its eventual reconstruction.

At the base of the Lepidosauria
in the LRT nests Megachirella, derived from a sister to Sophineta (Early Triassic) and Saurosternon + Palaegama (Latest Permian) and kin. Sisters to Megachirella within the Lepidosauria include the tritosaurs Tijubina + Huehuecuetzpalli (Early Cretaceous), Macrocnemus (Middle Triassic) and the prosquamate Lacertulus (Late Permian). Also similar and related to Palaegama is Jesairosaurus (Middle Triassic). So the genesis of the Lepidosauria is Late Permian. The initial radiation produced taxa that continued into the Early Cretaceous. The radiation of derived taxa continued with three major clades, only one of which, the Tritosauria, is now completely extinct.

Note
It is important to remember that lepdiosaurs and protorosaurs are not closely related, but arrived at similar bauplans by convergence, according to the LRT. The former is a member of the new Lepidosauromorpha. The latter is a member of the new Archosauromorpha. Last common ancestor: Gephyrostegus and kin.

Nesting at the base of the Lepidosauria
in the Sphenodontia clade makes the BSRUG specimen an important taxon. Let’s see if and when this taxon is nested by academic workers that they include all of the pertinent taxa and confirm or re-discover the Tritosauria. The LRT provides a good list of nearly all of the pertinent taxa that should be included in that future study, many of which are listed above. Based on that list, the BSRUG specimen is a late-survivor of a perhaps Middle Permian radiation of basal lepidosaurs.

References
Coram RA, Radley JD and Benton MJ 2017. The Middle Triassic (Anisian) Otter Sandstone biota (Devon, UK): review, recent discoveries and ways ahead. Proceedings of the Geologists’ Association in press. http://dx.doi.org/10.1016/j.pgeola.2017.06.007

Arcticodactylus a tiny Greenland Triassic pterosaur

Arcticodactylus cromptonellus (Kellner 2015, originally Eudimorphodon cromptonellus Jenkins et al. 1999, 1999; MGUH VP 3393) Late Triassic ~210mya ~8 cm snout to vent length was a tiny pterosaur derived from a sister to Eudimorphodon ranzii and phylogenetically preceded Campylognathoides and BSp 1994 specimen attributed to Eudimorphodon. Whether it was a juvenile or a tiny adult cannot be determined because juveniles and even embryos are identical to adults in pterosaurs. Note that that rostrum was not shorter and the orbit was not larger than in sister taxa. This specimen is one of the smallest known pterosaurs., but not THE smallest (Fig. 1) contra the Wikipedia article. That honor goes to B St 1967 I 276.

Figure 1. Articodactylus is evidently NOT the smallest pterosaur. That honor still goes to an unnamed specimen (not a Pterodactylus kochi juvenile) B St 1967 I 276.

Figure 1. Articodactylus is evidently NOT the smallest pterosaur. That honor still goes to an unnamed specimen (not a Pterodactylus kochi juvenile) B St 1967 I 276.

Distinct from E. ranzii,
the skull of Arctiodactylus had a rounder, less triangular orbit. The jugal was not as deep. The sternal complex did not have small lateral processes. The humerus was not as robust. The fingers were longer an more gracile. The prepubis was distinctly shaped.

Distinct from
Bergamodactylus the femur and tibia were smaller but the metatarsals were longer, compact and nearly subequal in length with IV smaller than III.

References
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A primitive pterosaur of Late Triassic age from Greenland. Journal of the Society of Vertebrate Paleontology 19(3): 56A.
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A diminutive pterosaur (Pterosauria: Eudimorphodontidae) from the Greenlandic Triassic. Bulletin of the Museum of Comparative Zoology, Harvard University 155(9): 487-506.
Kellner AWA 2015. Comments on Triassic pterosaurs with discussion about ontogeny and description of new taxa. Anais da Academia Brasileira de Ciências 87(2): 669–689

wiki/Eudimorphodon
wiki/Arcticodactylus

Rough chronology of basal tetrapods and basal reptiles

Today we’ll look at WHEN
we find fossils of basal tetrapods and basal reptiles. According to the large reptile tree (959 taxa, LRT, subset shown in Fig. 1), oftentimes we find late survivors of earlier radiations in higher strata. The origin of Reptilia (amphibian-like amniotes) extends back to the Devonian and Early Carboniferous now, not the Late Carboniferous as Wikipedia reports and as the Tree of Life project reports.

Figure 1. Color coded chronology of basal tetrapods and reptiles.We're lucky to know these few taxa out of a time span of several tens of millions of years.

Figure 1. Color coded chronology of basal tetrapods and reptiles.We’re lucky to know these few taxa out of a time span of several tens of millions of years. Click to enlarge.

The Late Devonian 390–360 mya
Here we find late survivors of an earlier radiation: Cheirolepis, a basal member of the Actinopterygii (ray-fin fish) together with Eusthenopteron and other members of the Sarcopterygii (lobe-fin fish). Coeval are basal tetrapods, like Acanthostega and basal reptiles, like Tulerpeton. These last two launch the radiations we find in the next period. The presence of Tulerpeton in the Late Devonian tells us that basal Seymouriamorpha and Reptilomorpha are waiting to be found in Devonian strata. We’ve already found basal Whatcheeriidae in the Late Devonian taxa Ichthyostega and Ventastega.

Early Carboniferous 360–322 mya
Here we find the first radiations of basal reptilomorphs, basal reptiles, basal temnospondyls,  basal lepospondyls and microsaurs, lacking only basal seymouriamorphs unless Eucritta is counted among them. It nests outside that clade in the LRT.

Late Carboniferous 322–300 mya
Here we find more temnospondyls, lepospondyls and phylogenetically miniaturized archosauromorphs, likely avoiding the larger predators and/or finding new niches. Note the first prodiapsids, like Erpetonyx and Archaeovenator, appear in this period, indicating that predecessor taxa like Protorothyris and Vaughnictis had an older, Late Carboniferous, origin. Not shown are the large basal lepidosauromorphs, Limnoscelis and Eocasea and the small archosauromorphs, Petrolacosaurus and Spinoaequalis.

Early Permian 300–280 mya
Here we find the first fossil Seymouriamorpha and the last of the lepospondyls other than those that give rise to extant amphibians, like Rana, the frog. Here are further radiations of basal Lepidosauromorpha, basal Archosauromorpha (including small prodiapsids), along with the first radiations of large synapsids.

Late Permian 280–252 mya
Here we find the next radiation of large and small synapsids, the last seymouriamorphs, and derived taxa not shown in the present LRT subset.

Early/Mid Triassic 252 mya–235 mya
Among the remaining basal taxa few have their origins here other than therapsids close to mammals. Afterwards, the last few basal taxa  listed here, principally among the Synapsida, occur later in the Late Triassic, the Jurassic and into the Recent. Other taxa are listed at the LRT.

What you should glean from this graphic
Taxa are found in only the few strata where fossilization occurred. So fossils are incredibly rare and somewhat randomly discovered. The origin of a taxa must often be inferred from phylogenetic bracketing. And that’s okay. This chart acts like a BINGO card, nesting known taxa while leaving spaces for taxa we all hope will someday fill out our card.

 

 

More evidence that Meiolania is a basal turtle

Figure 5. Meiolania, the most primitive of known turtles, has lateral forelimbs, like non turtles.

Figure 1. Meiolania, the most primitive of known turtles, has lateral forelimbs, like non turtles. Extant turtle elbows point anteriorly. 

Earlier we looked at the bizarre and seeming highly derived skulls of Meiolania (Fig. 1) and Niolamia, (Fig. 2) two large late-surviving meiolanid turtles that are only known from rather recent fossil material following an undocumented origin in the Late Permian or Early Triassic.  They both nested as sisters to Elginia (Fig. 2; Late Permian), a toothed turtle sister with horns. So the horns and frills are primitive, not derived.

Figure 2. Comparing the skulls of Elginia, with teeth, and the turtle, Niolamia, toothless.

Figure 2. Comparing the skulls of Elginia, with teeth, and the turtle, Niolamia, toothless.

Here’s a review
of various turtle ancestor candidates in graphic format (Fig. 3). A candidate touted by several recent authors, Eunotosaurus, is among those shown.

Figure 1. In traditional studies Eunotosaurus nests at the base of turtles, but that is only in the absence of the taxa shown here and correctly scored. Here Eunotosaurus is convergent with turtles, but not related. Turtles arise from small pareiasaurs.

Figure 3. In traditional studies Eunotosaurus nests at the base of turtles, but that is only in the absence of the taxa shown here and correctly scored. Here Eunotosaurus is convergent with turtles, but not related. Turtles arise from small pareiasaurs.

Cervical count
Pareiasaurs have 6 cervicals. Turtles have 8, several of which are tucked inside the shell. Proganochelys, often touted as the most basal turtle, has 8 cervicals. Horned Meiolania, at the base of the hard-shell turtles has 6 cervicals with ribs and 2 without ribs according to Gaffney (1985; Fig. 4). Most living turtles do not have cervical ribs. In Proganochelys cervical ribs are much reduced.

Note that in Odontochelys (Fig. 3 a similar situation arises where the all the vertebrae anterior to the expanded ribs are considered cervicals, even though two are posterior to the scapula. Similarly, in Proganchelys (Fig. 3) the last cervical is posterior to the scapula. In other tetrapods (let me know if I am forgetting any), all the cervicals are anterior to the scapula and a few dorsal vertebrae typically appear anterior to the scapulae. The tucking of the scapula beneath the ribs of turtles is a recurring problem with many offering insight.

Figure 1. Meiolania cervicals. Did Gaffney follow tradition when he identified 8 cervicals here? Only 6 have ribs and the shape changes between 6 and 7.

Figure 4. Meiolania cervicals. Did Gaffney follow tradition when he identified 8 cervicals here? Only 6 have ribs (yellow) and the shape changes between 6 and 7.

There are several different possible nesting sites
for turtles with regard to living reptiles (including mammals and birds, Fig. 5). Only the LRT (in yellow) has not made it to the academic literature (after several tries) because it is the only tree topology that splits Archosauromorpha from Lepidosauromorpha in the Viséan, further in the past than other workers venture to place reptiles that still look like amphibians. Until we get the basic topology down and agreed upon, it is going to be difficult to nest turtles properly.

Figure 2. Various hypotheses regarding turtle origins. The LRT is added in yellow.

Figure 5. Various hypotheses regarding turtle origins. The LRT is added in yellow. Most studies show Synapsida as the basal dichotomy, whereas the LRT divides Lepidosauromorpha from Archosauromorpha together with two separate origins for diapsid reptiles.

References
Gaffney ES 1985. The cervical and caudal vertebrae of the cryptodiran turtle, Meiolania platyceps, form the Pleistocene of Lord Howe Island, Australia. American Museum Novitates 2805:1-29.

Ozimek volans: long and skinny, but not a glider

Updated a few hours later
with a phylogenetic analysis nesting Ozimek with Prolacerta.

A new and very slender
Late Triassic (230 mya) reptile from lake sediment, Ozimek volans (Dzik and Sulej 2016; ZPAL AbIII / 2512; Figs. 1-3) appears to look like a variety of taxa on both sides of the great divide within the Reptilia: macrocnemids and protorosaurs. Based on the long, thin-walled neck bones, Ozimek was originally considered a possible pterosaur or tanystropheid, but Dzik and Sulej nested it with Sharovipteryx (Fig. 1), the Middle Triassic gliding fenestrasaur, and considered it a big glider (Fig. 3).

Figure 1. Three in situ specimens attributed to Ozimek. The largest humerus (purple) is scaled up from the smaller specimen. These are 80% of full scale when viewed at  72 dpi. To me, that 2012 ulna looks like a tibia + fibula and the 2012 humerus looks like a femur, distinct from the 2512 humerus.

Figure 1. Three in situ specimens attributed to Ozimek. The largest humerus (purple) is scaled up from the smaller specimen. These are 80% of full scale when viewed at  72 dpi. To me, that 2012 ulna looks like a tibia + fibula and the 2012 humerus looks like a femur, distinct from the 2512 humerus.

The large reptile tree
(LRT) does not nest the much larger Ozimek with tiny Sharovipteryx, but with Prolacerta (Fig. 2). While lacking an antorbital fenestra, Dzik and Sulej consider Ozimek an archosauromorph. They also consider Sharovipteryx an archosauromorph.  Like all fenestrasaurs, Sharovipteryx has an antorbital fenestra by convergence with archosauromorpha.

Figure 2. Reconstruction of Ozimek with hands and feet flipped to a standard medial digit 1 configuration and compared to Sharovipteryx and Prolacerta to scale. Note the short robust forelimbs and elongate pectoral elements of Sharovipteryx, in contrast to those in Ozimek.

Figure 2. Reconstruction of Ozimek with hands and feet flipped to a standard medial digit 1 configuration and compared to Sharovipteryx and Prolacerta to scale. Note the short robust forelimbs and elongate pectoral elements of Sharovipteryx, in contrast to those in Ozimek. Compared to Prolacerta the girdles are much smaller, indicating a much smaller muscle mass on the limbs, probably making it a poor walker. Perhaps it floated to support its weight.

Sediment
The authors report on the limestone concretion, “the fossils under study occur in the one-meter thick lacustrine horizon in the upper part where the dominant species are aquatic or semi-aquatic animals. These also include the armored aetosaur Stagonolepis, possible dinosauriform Silesaurus, crocodile-like labyrinthodont Cyclotosaurus, and the predatory rauisuchian Polonosuchus.”

Figure 1. Dzik and Sulej are so sure that their Ozimek was a spectacular big sister to Sharovipteryx that they gave a model gliding membranes and used the largest disassociated humerus for scale. More likely it was an aquatic animal that did not move around much underwater.

Figure 3. Dzik and Sulej are so sure that their Ozimek was a spectacular big sister to Sharovipteryx that they gave a model gliding membranes and used the largest disassociated humerus for scale. More likely it was an aquatic animal that did not move around much underwater due to its weak musculature. The model was built based on crappy reconstructions of Sharovipteryx.

Forelimbs
Dzik and Sulej take the word of Unwin 2000, who did not see forelimbs in Sharovipteryx (and illustrated it with Sharov’s drawing), rather than the reports of Sharov 1971, Gans et al. 1987 and Peters 2000 who did see forelimbs. The latter three authors found the  forelimbs were short with long fingers, distinct from the gracile forelimbs and short fingers found in Ozimek. So, that’s one way to twist the data to fit a preconception. New specimens often get a free pass when it comes to odd interpretations, as we’ve seen before in Yi qi and others.

Manus and pes
In the reconstruction it appears that the medial and lateral digits are flipped from standards. This is both shown and repaired in figure 2.

According to the scale bars
the ZPAL AbIII/2511 specimen is exactly half the size of the ZPAL AbIII/2012 specimen. That issue was not resolved by the SuppData  The humerus shown in the 2012 specimen is not listed in the SuppData. Even so, the authors also ally another large humerus (2028) to Ozimek, and this provides the large scale seen in the fleshed-out model built for the museum and the camera (Fig. 3).

Built on several disassociated specimens
the reconstruction of Ozimek (Fig. 2) is a chimaera, something to watch out for.

Initial attempts at a phylogenetic analysis
based on the reconstruction pointed in three different directions, including one as a sauropterygian based on the illustrated dorsal configuration of the clavicles relative to the coronoids. If the clavicles are rotated so the vernal rim is aligned with the anterior coracoids the dorsal processes line up correctly with the indentations on the scapula (Fig. 2), alleviating the phylogenetic problem.

Lifestyle and niche
Sharovipteryx has an elongate scapula and coracoid, traits lacking in Ozimek. Sharovipteryx also has an elongate ilium and deep ventral pelvis, traits lacking in Ozimek. The limbs are so slender in Ozimek, much more so than in the much smaller Sharovipteryx, that it does not seem possible that they could support the large skull, long neck and long torso in the air – or on the ground. This is a weak reptile, likely incapable of rapid or robust locomotion. So instead of gliding, or even walking, perhaps Ozimek was buoyed by still water. Perhaps it moved its spidery limbs very little based on the small size of the available pectoral and pelvic anchors for muscles, despite those long anterior caudal transverse processes. Those might have been more useful at snaking a long thin tail for propulsion.

If we use our imagination,
perhaps with a large oval membrane that extended from the base of the neck to fore imbs to hind limbs Ozimek might have been like a Triassic water lily pad, able to dip its skull beneath the surface seeking prey, propelled by a flagellum-like tail. Not sure how else to interpret this set of specimens.

References
Dzik J and Sulej T 2016. An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages. Acta Palaeontologica Polonica 61 (4): 805–823.

wiki/Ozimek (in Polish)

Surviving the Permian-Triassic boundary

For those of you
who typically ignore the letters to the editor, this is one exchange that you might find interesting.

Earlier Bill Erickson asked me 
“So, why, in your opinion, did diapsid reptiles suddenly — and I do mean suddenly — become so dominant beginning in or about Carnian time, and remain dominant thereafter throughout the Mesozoic, after millions of years of synapsid dominance beforehand in the mid-to-late Paleozoic and early Triassic?”

I answered
-Why- questions are very tough in Science, Bill. I don’t know the answer to your question. I don’t have an opinion either.

B. Erickson replied
“David – I’d agree for the most part, but I do think Peter Ward made a good case [in his book Gorgon.] that synapsids had a less efficient respiratory system than many archosaurs, and that lower atmospheric oxygen was a major driver in the end-Permian extinction. Of course, some synapsids, especially cynodonts, were diverse in early Triassic, and that’s another story.”

To which I replied
Bill, I have heard of Ward’s hypothesis and it makes a certain sense. Let me toss this off-the-cuff idea at you.

Synapsids, to my knowledge, survived the Permian extinction event by burrowing, or perhaps there was a part of the world they found refuge in. If the former, whether in dirt or leaf litter, both niches seem to support small to tiny tetrapods. See Pachygenelus, Megazostrodon and Hadrocodium for examples. [Well, those are all bad examples as they are all Early Jurassic, but consider the small earliest Triassic cyndont, Thrinaxodon (Fig. 1).]

Figure 1. Thrinaxodon, a burrowing synapsid from the Early Triassic was similar in size and proportion to the Late Permian ancestor of all archosauriformes, Youngoides (Fig. 2). These similar basal taxa were the genesis for all later mammals, dinosaurs and birds. 

Figure 1. Thrinaxodon, a burrowing synapsid from the Early Triassic was similar in size and proportion to the Late Permian ancestor of all archosauriformes, Youngoides (Fig. 2). These similar basal taxa were the genesis for all later mammals, dinosaurs and birds.

On the diapsid/archosauriform side, the likely aquatic proterosuchids cross the Permo-Triassic boundary, then give rise to all the familiar archosauriformes. In the water niche larger tetrapods, like crocs, are supported. As Malcolm Gladwell documented so well [in his book Outliers], an initial minor advantage can accelerate or become emphasized over time.

So, again guessing here, the largely nocturnal denizens of the burrows and leaf litter apparently played to their environment and stayed small yielding the otherwise unoccupied largely diurnal aquatic-grading-to-terrestrial taxa the larger size as they played to their niche. Maybe the diapsids just got to the outdoors/daylight niche first.

Figure 2. Updated image of various proterosuchids and their kin. When you see them all together it is easier to appreciated the similarities and slight differences that are gradual accumulations of derived taxa. Youngoides and the earliest proterosuchids were Late Permian. Others were Early Triassic and later.

Figure 2. Updated image of various proterosuchids and their kin. When you see them all together it is easier to appreciated the similarities and slight differences that are gradual accumulations of derived taxa. Youngoides and the earliest proterosuchids were Late Permian. Others were Early Triassic and later.

Along the same lines, the lepidosaur diapsids stayed relatively small and unobtrusive except for the Late Triassic sea-going tanystropheids and Late Cretaceous sea-going mosasaurs, perhaps following the same niche rules and regs as above. Pterosaur lepidosaurs also experienced much greater size in the Late Cretaceous.

Just a thought/opinion supported by what I can recall at the moment. Let me know your thoughts if you’d like to continue this thought journey. [END]

And then beyond that exchange…
I note that EarlyTriassic synapsid taxon list also includes the large dicynodont, Kanneymeira and a number of small therocephalians. Burrowing taxa are pre adapted to a nocturnal existence. The big dicynodont must have survived in some sort to refuge niche.

The standard story
includes the notion that dinosaurs and other archosauriform predators were snapping up every little synapsid they saw, so the survivors became invisible by becoming nocturnal and or really tiny… and that probably continued throughout the Mesozoic, with both clades improving generation after generation.

erythrosuchid

Figure 3. Basal archosauriforms from the Early Triassic,  including Euparkeria, Proterosuchus and Garjainia.

The twist brought to you by
the large reptile tree is the outgroup for the Archosauriforms, Youngoides, is a small, Thrinaxodon-sized terrestrial younginiform diapsid (Fig. 1). Perhaps an early affinity for rivers and lakes was the key to survival among proterosuchid archosauriforms when the P-Tr problems escalated. But also note that the small ancestors to dinosaurs, the euparkeriids, (Fig. 3) ALSO survived the P-Tr boundary as small terrestrial forms alongside the much larger terrestrial erythrosuchids, otherwise known as giant younginids.

Maybe we’ll never know…
but it’s interesting to put at least some of the puzzle pieces together.

 

 

SVP 5 – Triassic pterosaur from Utah

Britt et al. (2105) found a Late Triassic pterosaur in Utah, described in the following SVP abstract.

From the abstract:
“We previously reported on a wealth of tetrapods, including multiple individuals each of a coelophysoid, a drepanosauromorph, two sphenosuchian taxa, and two sphenodontian taxa. All are preserved along the shoreline of  a Late Triassic oasis in the Nugget Sandstone at the Saints & Sinner Quarry (SSQ). Recently, we discovered a non-pterodactyloid pterosaur at the quarry, represented by a partial uncrushed, associated/articulated skull imaged via micro CT. The premaxillaries are spoon-shaped rostrally; the maxilla is a simple bar with a needle-like nasal process, the suborbital jugal/quadratojugal blade is high; the nasal is a short, narrow rectangle; and the fused frontals are wide with a moderately high, tripartite sagittal crest. The lower jaws are complete, with a long, slender dentary terminating rostrally in a downward-bend with a ventral expansion, a short postdentary complex and a short retroarticular process. The quadrate-articular joint is well above the tooth row. At least three, widely spaced, conical teeth are in the premaxilla; maxillary teeth are mesiodistally long (3 widely-spaced mesially and 7 close together distally); and on the dentary there are two apicobasally high, widely-spaced mesial teeth and ~20 small, multicusped, low-crowned distal teeth. The frontals and lower jaws are extensively pneumatized. With a 170 mm-long lower jaw, this is two times larger than other Triassic pterosaurs and only the second indisputable Triassic pterosaur from the Western Hemisphere (the other is from Greenland). This is the only record of desert-dwelling nonpterodactyloids and it predates by >60 Ma all known desert pterosaurs. Whereas most pterosaurs are known from fine-grained marine or lacustrine environments, and other Triassic forms are smaller, the SSQ specimen shows that early pterosaurs were widely distributed, attained a large size, and lived in wide range of habitats, including inland deserts far (>800 km) from the sea. Finally, the SSQ pterosaur corroborates the Late Triassic age of the fauna based on drepanosaurs because pterosaurs with multicusped teeth are presently known only from the Upper Triassic.”

The description
sounds like an early dimorphodontid, but withe the deep jugal of Raeticodactylus. The size of the skull is similar to both. Unfortunately, too few clues to go on. I’ll wait for the paper… eagerly!

References
Britt BB, Chure D, Engelmann G and Dalla Vecchia F et al.  2015.
A new, large, non-pterodactyloid pterosaur from a Late Triassic internal desert environment with the eolian nugget sandstone of Northeastern Utah, USA indicates early pterosaurs were ecologically diverse and geographically widespread. Journal of Vertebrate Paleontology abstracts.