Thursday, 18 June 2015

Jurassic World - the great debate

I have to say I didn't see myself wading into the debate about Jurassic World. By the debate I mean science versus artistic licence in the name of entertainment, or as some news reporters have unflatteringly reported it… ‘Nerds’ versus the public. Added to this Jurassic World has made ~$500 million in its opening weekend, $208.8 domestic, beating the Avengers to the top spot. It is now the center of many more debates as reviewers scrutinise it, and they will be discussed in the latter part of this post.

There are many reasons I have made this late entry to the debate;
1. I have only just seen the movie a week into its opening.
2. I decided a long time ago accuracy doesn't matter to me, Jurassic Park and its latest sequel Jurassic World are corny action packed monster movies, not documentaries. However, I had no desire to take opposition with my peers, given that I respect their opinions and they're entitled to them.
3. I wanted to reserve my judgement until I had seen the entire movie, not a theatrical trailer like a certain Marvel Studios top dog (Joss Whedon).
4. I really enjoyed the movie.
5. In my opinion there are elements of each argument that have merit and after taking a back seat for so long, and now having enjoyed the film for what it is I want to air these opinions. This seems the most viable format.

So, a little about the film… A short synopsis and review if you will. [spoiler alert]

Jurassic Park was not a success, even it’s principal funder and visionary Richard Hammond decided not to endorse his own park after a party of independent reviewers fell victim to the greed of men and a nasty pack of ‘Velociraptors’. The park’s creators had spent so long finding out if they could create dinosaurs, they didn't stop to think if they should. The park had been out of bounds for around 12 years with the exception of a couple of unbelievably ridiculous forays back to the park and its neighbouring island. Now Jurassic Park has been re-modelled Jurassic World by Hammond’s successor Simon Masrani and he's “spared no expense”. A sophisticated control centre, new paddocks, a monorail and ‘gyro-spheres’ (seemingly stolen from Rip Hunter) and presumably a much better screening of employees has made the park a much safer place. However, in an attempt to avoid the inevitable slump in visitors and “coupon days” (jp1) the geneticists are making the animals unnaturally large and veracious. The latest attempt to draw in custom, or so we're lead to believe is the new super predator Indominus rex. This super predator is a blend of so many top predators of the Mesozoic I don't care to list them. I. rex is so smart it even manages to outsmart the alpha of the raptor pack Owen Grady (Chris Pratt). With I. rex on the loose horrific scenes unfold, including the release of flocks of pterosaurs Pteranodon and Dimorphodon, causing the best helicopter related death in all cinema history. Around about this time it becomes clear that a military researcher was working subversively behind the scenes to create I. rex  so that he could demonstrate the utility of weaponising dinosaurs. In the end it takes a supreme tag team to put I. rex to rest, which includes Blue the ‘velociraptor’ taking a leaf out of Optimus Prime’s book (Age of Extinction).

My verdict is that this is the sequel Jurassic Park deserved and finally got. It went back to the original genre - there's not much horrific about going into danger with full knowledge of it, that's an adventure movie. In my opinion it was a very enjoyable movie all in all.

I think I've made it very clear that I've enjoyed Jurassic World, and I've not just looked past the scientific inaccuracies, but plainly not cared despite my career path as a palaeontologist. I swallowed the lines referring to inaccuracies very comfortably. In the movie the characters refer to the dinosaurs as monsters, not dinosaurs, presenting understandable inaccuracies due to the missing genome and not only that but they are sensationalised and oversized. Despite this some people, enthusiasts and professional scientists alike have complained about the lack of accuracy and I am sympathetic to their point of view.

When I first heard that feathers weren't adorning the dinosaurs I was myself quite disappointed. However, the disappointment was short lived. I was initially under the impression Jurassic World was going to be a reboot of of Jurassic Park, not another sequel. It makes sense to me that the same genetic procedures and bloodlines, which are only a few generations into a breeding program would continue to lack feathers. I like the continuity. Also, the Jurassic Park franchise is not a showcase for science, but rather entertainment that uses just enough realism to create the believability that keeps audiences in suspense.

The inaccuracies don't end there though. One of my very few criticisms is that the stegosaurs go from a good representation in The Lost World (JP2) to poor. The main reason this disappoints me is the same as why I am okay with the lack of feathers, continuity. There are other examples of old hand JP stars taking a step backwards, but they are only bit parts and detract very little from the end product.

Close to my heart are pterosaurs. No one watching Jurassic World would know that they had a furry covering. Also, the latest theories over quad-launching were all too obviously omitted. Naked, ugly, big bodied Pteranodon had starred in JP3, so I would be a hypocrite of what's good for the dinosaur isn't for the pterosaur, however Dimorphodon  is a new addition to the cast and could have been a bit more realistic for the sake of believability. The pterosaur in JP3 was my least favourite moment of all the films well before I became a palaeontologist, let alone a pterosaur researcher… It's just monstrously unrealistic. Despite these bugbears the pterosaur scene was stunningly tongue in cheek and action packed, much like some scenes in Jurassic Park and mirroring the human interaction and dialogue of Jurassic World star Chris Pratt. So amazingly I was laughing, knee slapping and enjoying the scenes that by all rights and according to some reporters should have had me up in arms (more in a bit)!

For airing similar opinions based on observations from theatrical trailers many enthusiasts took to the blogosphere, tweeted and put up Facebook statuses about their intolerance of the new movie. Likewise, reporters which were also armed with as little knowledge as a trailer cooked up articles regurgitating 140 character tweets from palaeontologist’s reactions to the trailer accompanied by satirical commentary. had an article slightly offensively titled “Dinosaur Nerds Are Already Mad At Jurassic World”. Some of the people reporters are calling dinosaur nerds are professional scientists with a great deal of education, passion and experience, this is like us calling a journalist a ‘hate-monger’ for example. This just isn't on.

Yet more social media controversy surrounds the latest in the Jurassic Park franchise, namely sexism. Now this is well beyond the remit of Mesozoic Monsters, but it's worth a mention after discussing the accuracy argument… After all, what's good for the dinosaur is good for the pterosaur. I'm going to approach this debate from a purely logical and academic point of view. A quick google search defines sexism as “prejudice, stereotyping, or discrimination, typically against women, on the basis of sex”, this definition is sexist by its own admission, given that it stereotypes the victims. The sexist argument was first presented by Marvel’s Joss Whedon (wasn't this the guy that had a 16yo girl killing vampires, except those she fell hopelessly in love with?), based on an out of context trailer, but since the movie’s release social media and reports have sunk their T. rex like teeth into it - after the dinosaur nerds got boring. The reason for the Joss’ outraged tweet was that the female lead (NOT I. rex), Claire Dearing is a hard working, stiff female character, juxtaposed to Owen’s free spirit. Later, the characters evolve over a formative journey, Owen becomes a bit more serious and badass while Claire becomes more maternal… And badass. Now this is not prejudice or discrimination, so the complaint must be stereotyping. I guess this stereotyping is a byproduct of the writing process, whereby the writing team had to choose the characteristics of the cast and how they would best function together on screen to draw the viewer into the story and support them in their journey for survival. I fully admit that Claire Dearing and Owen Grady were stereotypes, but were those based on sex? Maybe, this is a formula that's been used in the past and it is often gender specific. However, you’re working with 50/50… Would the same characters work with different genders? They kind of did! Dr Alan Grant at the start of Jurassic Park had no paternal instinct, quite the opposite even, and was so obsessed with his work he couldn't even take criticism from a prepubescent boy that for some reason was in the middle of the badlands. In fact it was only the promise of another 3 years funding that he would even consider going anywhere for a weekend away – by the way if anyone wants to fund my research for 3 years I'll come to your park and I'll endorse it even if your exhibits try to eat me. Guess what, after a formative journey he gains that paternal instinct… And is pretty badass! So, is Jurassic World sexist or have the feminists that criticised it become blind to the fact that they are stereotyping women to be more maternal than men are paternal? This is a can of worms. All said and done, in my opinion it didn't detract from the movie and the five people I went to the cinema (3 women, 3 men including myself) with didn't even notice. However, what was noticed was the catwalk pose Chris Pratt pulled getting in the elevator, which ended in his objectification by the women in our group. One of them even made a remark in the cinema that is too rude for Mesozoic Monsters! This is a total reversal of roles. It's certainly not a Michael Bay moment, but it is arguably objectifying the male role. Nonetheless, it didn't bother me… I'm pretty sure half the men in the audience even had the same reaction as the women Pratt is such a man mountain at the moment.

In the time I've been writing this post Jurassic World has become a massive pro-animal rights ambassador, racist, and I'm pretty sure it just killed a puppy. At the end of the day all the media attention on accuracy, sexism and other issues is exactly what you'd expect from a disenfranchised, negative media reacting to the worlds biggest movie sensation. As I said above Jurassic World is the sequel Jurassic Park deserved. It's not just a monster movie, it's a monster of a movie. Entertaining, action packed, and sympathetic to the original. 8.5 out of 10.

Friday, 24 October 2014

The pterodactyl tree

The relationships within Pterosauria have been the subject of phylogenetic debate since the 19th Century. In the very latest 20th century it was subject to rigorous cladistic analyses, which became more refined and comprehensive in the early two-thousands. There have been multiple approaches to pterosaur phylogeny, tackling both the Pterosauria as a whole and taking a ‘split approach’ -studying the stem-group non-pterodactyloids and the pterodactyloids separately.

In a recent study (Vidovic and Martill 2014) a contentious distribution of pterodacyloids was recovered during a cladistic analysis. The analysis was a pterodactyloid-specific study, and the first published to use non-pterodactyloid monofenestratans as the out-group. Being a pterodactyloid-specific analysis it was not a completely comprehensive analysis, thus it does not hold more “weight” than say the analysis of Andres et al. 2014. However, it is the largest pterodactyloid analysis to date, utilising more effective methods of extracting data from morphometrics (TNT’s continuous states function), and the characters were scrutinized to avoid compound characters (i.e. those characters that do not express all the information you tell them). For these reasons the new phylogeny presents an interesting hypothesis of pterosaur relationships that should not be dismissed without good reason.

A single most parsimonious tree of the Pterodactyloidea recovered using a TNT “new technology search”.Named nodes: 1 = Monofenestrata Lü et al. 2010 [30]; 2 = Pterodactyloidea Plieninger 1901 [31]; 3 = Ctenochasmatidae Nopcsa 1928 [32]; 4 = Lophocratia Unwin 2003 [33]; 5 = Aurorazhdarchidae fam. nov.; 6 = Ornithocheiroidea Seeley 1891 [34]; 7 = Istiodactylidae Howse et al. 2001 [35]; 8 = Pteranodontia Marsh 1876 [36]; 9 = Anhangueridae Campos and Kellner 1985 [37]; 10 = Tapejaroidea Kellner 1996 [38]; 11 = Azhdarchoidea Nesov 1984 [39]; 12 = Azhdarchidae Nesov 1984 [39]; 13 = Tapejaridae Kellner 1989 [40].

Now that I have explained why the cladogram is worth consideration, it is worth saying what is so different about it.

As I have previously mentioned the Vidovic and Martill (2014) analysis was the first to use non-pterodactyloid monofenestratans as the out-group. The significance of this out-group is that species of Darwinopterus (as well as Wukongopterus and Cuspicephalus) possess the confluent nares and antorbital fenestra (nasoantorbital fenestra) that pterodactyloids have, but in every other sense are more similar to non-pterodactyloids. Because this non-pterodactyloid group is so close to pterodactyloids we can be confident that Darwinopterus can polarise the characters effectively. Perhaps due to the use of Darwinopterus as the out-group, or the splitting down of compound characters, neither the Ctenochasmatoidea nor the Archaeopterodactyloidea have been recovered. The Ctenochasmatoidea and Archaeopterodactyloidea each contain the Gallodactylidae, the Ctenochasmatidae and Pterodactylus, the difference between the two is that the former is exclusive of Germanodactylus and the latter is inclusive of Germanodactylus. Maisch et al. (2004) conducted a specific analysis on dsugaripteroids (following Unwin 2003, with Ctenochasmatoidea and Germanodactylus included in Dsungaripteroidea) and concluded that Germanodactylus is paraphyletic –meaning it contains two or more closely related genera. In the Vidovic and Martill (2014) analysis the two Germanodactylus species were found to be incredibly distinct, perhaps even polyphyletic –meaning the inferred relationship is based on homoplasy (convergent characters) rather than symplesiomorphies (shared ancestral characters). In the analysis Germanodactylus cristatus was found to be the sister taxon to dsungaripterids and azhdarchoids, closer to Unwin’s (2003) hypothesis, whereas “Germanodactylus rhamphastinus” is the sister taxon to the new family group Aurorazhdarchidae, which is part of Archaeopterodactloidea sensu Kellner (2003). So, neither of the most favoured hypotheses seen in other analyses are entirely supported by this analysis. Moreover, the family groups that are normally grouped together -Pterodactylus, the ctenochasmatids (Ctenochasmatinae and Gnathosaurinae), Gallodactylidae and Ardeadactylus- are spread out stepwise between the node for Pterodactyloidea and the unnamed clade containing ornithocheiroids and Germanodactylus. The rest of the cladogram is mostly uncontroversial.

"Darwinopterus robustidens"

Is this distribution of “ctenochasmatoids” (From now on I will refer to both cteno. and archaeo. as “ctenochasmatoids”) illogical?
Perhaps not.

The new (since 2009) knowledge of non-pterodactyloid monofenestratans demonstrates that many of the features originally considered to define “ctenochasmatoids” are plesiomorphies. In the case of Vidovic and Martill (2014) these plesiomorphies are shared by several groups making the characters symplesiomorphies. More recently, after the paper and cladogram being discussed were submitted and peer reviewed for publication, a paper on a new ornithocheiroid, Hamipterus was published (Wang et al. 2014). Hamipterus is interesting, because it is clearly an ornithocheiroid, but possesses a long fibrous headcrest similar to that found in Darwinopterus and Cuspicephalus. This means that long fibrous headcrests are certainly not confined to “ctenochasmatoids”, nor are elongate necks, or elongate wing-metacarpals. In conclusion, there are no obvious characters uniting “ctenochasmatoids” and therefore the taxa are ‘strung out’ as a series of meta-taxa between the pterodactyloid node and the common ancestor of ornithocheiroids and Germanodactylus cristatus.

Hamipterus skulls with fibrous bony headcrests

Reconstruction of an ornithocheiroid pterosaur

Given that the new hypothesis of pterodactyloid phylogeny is not just plausible, but in the light of new evidence quite likely, the major group of pterodactyloids with dentitions confined to the anterior rostrum and long pteroid bones (~65% the length of the ulna) required a name. Part of the study was funded by the Linnean Society and Systematics Association, in order to test the phylogenetic position of Aurorazhdarcho and correct the family name from “Protazhdarchidae” to Aurorazhdarchidae if it required one. Indeed the cladistic analysis found Aurorazhdarcho shared characters like a long pteroid bone with Aerodactylus, thus Aurorazhdarchidae was erected for them and their closest relatives. Cycnorhamphus and Gladocephaloideus were also included in the Aurorazhdarchidae, so should the name Gallodactylidae have been used instead?
Reconstruction of aurorazhdarchid, Aerodactylus - adult and juvenile
Gallodactylidae was erected without definition in a coffee table book (albeit an excellent one [Wellnhofer 1991]). Much later Gladocephaloideus (Lü et al. 2012) was included in the family, accompanied by a formal definition which excludes Ardeadactylus, Aerodactylus and possibly Aurorazhdarcho. Later still, Bennett (2013) performed a taxonomic review, in which he made Cycnorhaphus the only genus to occupy Gallodactylidae. Indeed there is quite a morphological distinction between Gladocephaloideus and Cycnorhamphus, although undoubtedly Gladocephaloideus more similar to Cynorhamphus than any of the other aurorazhdarchids with its reduced dentition. It is likely that the grouping of Aerodactylus with Gladocephaloideus in the cladogram is the result of juvenile specimens being used in the analysis, thus sharing juvenile features. This is the same problem that led to Aerodactylus being considered Pterodactylus for so long! So for now I will follow Bennett (2013),  Gallodactylidae can be considered monotypic -at least until an analysis proves Lü et al.’s (2012) hypothesis that all pterosaurs with less than 50 teeth group together (note that amending the diagnosis to pterosaurs possessing 64 teeth would include “G. rhamphastinus” which shares little in common with Cycnorhamphus). In my opinion Gallodactylidae shouldn't have its diagnosis amended excessively, instead it should be reclassified to Gallodactylinae and nest within the more inclusive Aurorazhdarchidae.

In conclusion, the new phylogenetic hypothesis is a challenge to the established phylogenies of the past 10 years. It will be interesting to see what happens when comprehensive analyses begin to become more refined in their character construction.


Bennett SC (2013) The morphology and taxonomy of the pterosaur Cycnorhamphus. Neues Jahrbuch Fur Geologie Und Palaontologie-Abhandlungen 267: 23–41. doi: 10.1127/0077-7749/2012/0295
Kellner AWA (2003) Pterosaur phylogeny and comments on the evolutionary history of the group In: Buffetaut E, Mazin MJ, editors. Evolution and Palaeobiology of Pterosaurs: Geological Society of London, Special Publications 105–137. 
Maisch MW, Matzke AT, Sun G (2004) A new dsungaripteroid pterosaur from the Lower Cretaceous of the southern Junggar Basin, north-west China. Cretaceous Research 25: 625–634. doi: 10.1016/j.cretres.2004.06.002
Lü J, Ji Q, Wei X, Liu Y (2012) A new ctenochasmatoid pterosaur from the Early Cretaceous Yixian Formation of western Liaoning, China. Cretaceous Research 34: 26–30. doi: 10.1016/j.cretres.2011.09.010 
Unwin DM (2003) On the phylogeny and evolutionary history of pterosaurs. In: Buffetaut E, Mazin MJ, editors. Evolution and Palaeobiology of Pterosaurs: Geological Society of London, Special Publications. 139–190. 
Wellnhofer, P. (1991): The illustrated encyclopedia of pterosaurs. – 192 pp.; London (Salamander Books).
Wang X, Kellner AWA, Jiang S, Wang Q, Ma Y, Paidoula Y, Cheng X, Rodrigues T, Meng X, Zhang J, Li N, and Zhou Z (2014). Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs from China. Current Biology. Forthcoming. doi:10.1016/j.cub.2014.04.054

Wednesday, 22 October 2014

Gotta catch ‘em all – Pterosaur taxonomy

Despite the name being brand spanking new, i.e. Aerodactylus Vidovic and Martill 2014, the specimens have been known to science for over a century and a half!
Type specimen of Aerodactylus scolopaciceps
Aerodactylus is a new genus name for the species Pterodactylus scolopaciceps Meyer 1860. If you don’t know your Velociraptor from your Deinonychus and you’re worried this has gone over your head, don’t worry… P. scolopaciceps was synonymised (subsumed under the name) with Pterodactylus kochi in the 1880’s by Zittel – who famously (in pterosaur research) has a pterosaur wing with soft tissues named after him. Zittel (1883) even suggested that P. kochi might be synonymous with P. antiquus. The name P. scolopaciceps was briefly used by Broili (1938), who considered the species to be valid due to the preservation of many of the features listed by Meyer (1860) in a second specimen. However, the name fell out of use again, and by the time Wellnhofer (1970) performed his review of German pterodactyloids the name had become a mere footnote.

Much later, in 2013 Chris Bennett published a paper that followed Zittel’s suggestion and synonymised P. kochi with P. antiquus, including the two specimens referred to P. scolopaciceps. This synonymisation was based on the growing support from Mateer (1976), Jouve (2004) Bennett (1996) himself, and new evidence from principal component analyses (PCA) and Nopcsa curves. It seemed a closed case. However, PCA is not statistics or repeatable with an altered dataset, unless a population shows a normal distribution. Likewise, Nopcsa curves are open to interpretation. Although PCA can be used to support, or refute hypotheses (whilst being treated with appropriate caution) a cluster does not necessarily provide meaningful data to a taxonomist. So, a -small, unassuming- question mark hung over the synonymy. 
Referred specimens of Aerodactylus scolopaciceps

Whilst studying many Pterodactylus specimens for a much larger project, I noticed that there were a few slight differences between some specimens of P. kochi (note: this was before Bennett’s paper). So when Bennett (2013) synonymised the species with P. antiquus I set to work, constructing hypotheses and testing them. Ideally I would have used a discriminant function analysis (DFA), which is a bit like a PCA but far more appropriate for answering taxonomic problems. Unfortunately data limitations meant that DFA was not an option. Instead, I used an exhaustive bivariate technique, which used statistics to tell me if removing or adding specimens significantly improved or diminished the relationship support for a group. The results were clear, the hypothesis of P. kochi and P. antiquus being different from specimens now called Aerodactylus scolopaciceps was supported, while confusion over P. kochi’s taxonomic validity remains.
Cladogram of Pterodactyloidea from Vidovic & Martill 2014

A cladistic analysis (which deserves its own article) demonstrated that Aerodactylus scolopaciceps is more closely related to Ardeadactylus longicollum, Aurorazhdarcho micronyx, Gladocephaloideus and Cycnorhamphus than Pterodactylus. The group containing Aerodactylus was named Aurorazhdarchidae, which increases our understanding of the family level diversity in the Bavarian plattenkalks. Aurorazhdarchidae is made up of pterosaurs traditionally considered ctenochasmatoids or archaeopterodactyloids with long necks, depressed rostra (concave beaks) and long pteroid bones.

The species name for Aerodactylus scolopaciceps comes from its superficial resemblance to a Woodcock or Snipe. In the paper we suggested that it could have occupied a similar ecological niche, probing sediments, or browsing on ground level for invertebrates. Admittedly in our paper we provide little evidence for these interpretations, but we would welcome a palaeoecological study on these specimens. Considering it is one of the best represented pterosaur taxa (with soft tissue) in the Solnhofen Plattenkalk the possibilities for future research are vast.

Finally, why name the genus after Aerodactyl?
Well, as with most things in science, it was a conversation in a pub that was responsible.
Bennett SC (1996) Year-classes of pterosaurs from the Solnhofen limestone of Germany: Taxonomic and systematic implications. Journal of Vertebrate Paleontology 16: 432-444.
Bennett SC (2013) New information on body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus. Palaeontologische Zeitschrift 87: 269-289.
Broili F (1938) Beobachtungen an Pterodactylus. Sitzungsberichte der Bayerischen Akademie der Wissenschaften, Mathematisch-naturwissenschaftliche Abteilung 1938: 139-154.
Jouve S (2004) Description of the skull of a Ctenochasma (Pterosauria) from the Latest Jurassic of eastern France, with a taxonomic revision of European Tithonian Pterodactyloidea. Journal of Vertebrate Paleontology 24: 542-554.
Mateer NJ (1976) A statistical study of the genus Pterodactylus. Bulletin of the Geological Institutions of the University of Uppsala 6: 97-105.
Meyer H (1860) Zur Fauna der Vorwelt: Reptilien aus dem lithographischen Schiefer des Jura in Deutschland und Frankreich. Frankfurt. 1-84.
Wellnhofer P (1970) Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Suddeutschlands. Bayerische Akademie der Wissenschaften, Mathematisch-Wissenschaftlichen Klasse, Abhandlungen 141: 1-133.
Zittel KA (1883) Über Flugsaurier aus dem lithographischen Schiefer Bayerns. Palaeontographica 29: 47-80.

Friday, 12 September 2014

Jidapterus: the pterosaur they got upside-down!

The first report of the pterosaur Jidapterus was by Dong, Sun & Wu 2003. Jidapterus is a Chinese pterosaur from the Jiufotang Formation of western Liaoning, making it Aptian in age. It belongs to the taxonomic family Chaoyangopteridae, which is itself in Azhdarchoidea. As an azhdarchoid it has a typically short last wing phalanx (knuckle); a long wing metacarpal (wrist bone) relative to the rest of the wing; a long neck relative to the body; and a large skull, lacking teeth. Initially Jidapterus was not assigned to a family, as Chaoyangopterus had only just been described itself, and it was considered to be a nyctosaur (Wang & Zhou 2003). It wasn’t until Shenzhoupterus Lü, Unwin, Xu & Zhang 2008 was described that the family Chaoyangopteridae was erected. Lü et al. (2008) defined Chaoyangopteridae as being azhdarchoids with an extremely thin premaxilla bounding the nasoantorbital fenestra (the external nares) [NAOF], while the NAOF itself extended back to the jaw joint – among other anatomical features. While the posterior portion of the skull in Jidapterus is poorly preserved, the specimen’s very large/expanded NAOF makes it difficult to argue against its placement in Chaoyangopteridae.
Jidapterus was reconstructed (Dong et al. 2003) as having a skull with a beautifully straight dorsal margin, whilst having a curved occlusal surface (biting surface). However, this is very different to Chaoyangopterus, Shenzhoupterus and Lacusovagus, which represent all of the good skull material within Chaoyangopteridae (see image below).
Reconstruction of Jidapterus by Dong et al. 2003

Skulls of chaoyangopterids A) Chaoyangopterus; B) Shenzhoupterus; C) Lacusovagus

Unfortunately I am limited by the images available to me and the content of the original paper (i.e. Dong et al. 2003) that I am able to translate, which is why I am now making the disclaimer that this is not incontrovertible fact, but some ideas that suggest the material needs to be revisited. From what I can tell looking at the images in the paper and the information that new fossil discoveries have provided me with, Jidapterus is upside-down!
Original figure of Dong et al. 2003: Note the label for maxilla (M) which is only present on the occlusal surface of the pterosaur rostrum.

My reasoning behind it - other than it being inconsistent with other chaoyangopterids - is as follows.
            1.       The orbit in azhdarchoids is lower than the dorsal margin of the NAOF.
            2.       The curved skull surface of the skull is longer than the straight surface, which would make the lower jaw significantly  shorter than the upper if the original reconstruction is correct.
            3.       It appears that part of the jugal (the bone defining the ventral margin of the orbit) is intact on the end of the “dorsal spar of the premaxilla”, which is likely to be the maxilla.
            4.       The neck is in articulation and is directed towards the “dorsal surface of the skull”; you would expect it to be directed towards the ventral surface.
So, bearing all that in mind the skull is most likely reconstructed upside-down, and in fact reconstructed very wrongly. I’m pretty sure that a more detailed examination of the material would reveal this and solidify our understanding of chaoyangopterids. See my new reconstruction below.
Reconstruction of Jidapterus
Morphologically, it appears more similar to Chaoyangopterus and Lacusovagus than Shezhoupterus.

Note: It seems that Lü et al. (2008) and Witton (2008), like myself, considered Jidapterus to have a “straight” occlusal surface to its rostrum, but provide no discussion and only give the reference to the original paper which clearly figures the straight margin as the dorsal process of the premaxilla.

Below is the original photo of the Jidapterus specimen with a scale bar, inferred from the wing phalanx lengths provided by Dong et al. (2003).

Dong, Sun & Wu. 2003. "On a new pterosaur from the Lower Cretaceous of Chaoyang Basin, Western Liaoning, China". Global Geology 22:1-7
Lü, Unwin, Xu & Zhang. 2008. A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften. DOI 10.1007/s00114-008-0397-5
Wang & Zhou. 2003. "Two new pterodactyloid pterosaurs from the Early Cretaceous Jiufotang Formation of Western Liaoning, China". Vertebrata PalAsiatica 41 (1): 34–41.
Witton. 2008. A new azhdarchoid pterosaur from the Crato Formation (Lower Cretaceous, Aptian?) of Brazil. Palaeontology 51:1289-1300.