Is Jeholopterus pregnant? And what’s hiding in plain sight beneath that left wing?

There seems to be an overlooked egg shape
inside Jeholopterus, the vampire pterosaur, at just the right place (Figs. 1, 2; IVPP V12705). It’s not full term, so embryo/hatchling bones are not readily visible (= fully ossified) and currently impossible to reconstruct. Then again, that patch could be just a scuff mark.

Figure 1. Jeholopterus GIF animation showing new left wing shape plus underlying debris, perhaps in the form of theropod feathers.

Figure 1. Jeholopterus GIF animation showing new left wing shape plus underlying debris, some in the form of theropod feathers. Folded wings on pterosaurs should essentially disappear. This new interpretation follows that hypothesis. Click for an enlarged image.

Remember
pterosaurs are fenestrasaur – tritosaurlepidosaurs, so they are able to retain eggs within the mother’s body until just before hatching. Even their super-thin, lizard-like egg shells (or lack thereof) supports the present tree topology of pterosaurs as lepidosaurs in the large reptile tree (LRT, 1315 taxa) and disputes traditional models of archosaurian origin first invalidated by Peters 2000 by phylogenetic testing. Pterosaur eggs found alone (not near the mother) outside the body (like the IVPP anurognathid) include full term embryos. The Hamipterus egg accumulation chronicles a mass death of pregnant mothers, probably by lake burping.

Moreover
Jeholopterus seems to have landed on (= sunk on to after death) some theropod/bird feathers or similarly shaped pond plants. I suspected there was something wrong with that way-too-broad-while-folded wing. Pterosaur wings typically fold up to near nothingness, like bat wings do, when folded. It turns out, that’s the case here, too. There is a fringed trailing edge where the current and correct blue area ends. Make sure you click for a larger image.

Figure 2. Possible Jeholopterus premature egg in which embryo bones are not well calcified. Ribs and gastralia on a separate frame.

Figure 2. Possible Jeholopterus premature egg in which embryo bones are not well calcified. Ribs and gastralia on separate frames.

Look up at the left hand
of Jeholopterus and you’ll see there is some sort of fossilized matter (greenish color added on overlay) on the stratum that the specimen sank to. The same appears to be happening near the left wing tip, where something like feathers or long leaves appear, giving the illusion of a little too much pterosaur wing chord, especially in comparison to the right wing, which appears ‘normal.’

Figure 3. Jeholopterus counter plate in UV with brachiopatagium traced.

Figure 3. Jeholopterus counter plate in UV with brachiopatagium traced. UV image from Kellner et al. 2010.

Jeholopterus ninchengensis (Wang, Zhou, Zhang and Xu 2002) Middle to Late Jurassic, ~ 160 mya, [IVPP V 12705] was exquisitely preserved with wing membranes and pycnofibers on a complete and articulated skeleton (see below). Unfortunately the fragile and crushed skull was undecipherable to those who observed it first hand. Using methods described here, Peters (2003) deciphered the skull and identified the IVPP specimen of Jeholopterus as a vampire. In that hypothesis, Jeholopterus stabbed dinosaurs with its fangs, then drank their blood by squeezing the wound with its plier-like jaws while hanging on with its robust limbs and surgically sharp, curved and elongated claws. From head to toe, Jeholopterus stood apart morphologically. It was not your typical anurognathid. Derived from a sister to the CAGS specimen attributed to Jeholopterus, the holotype of Jeholopterus was a phylogenetic sister to Batrachognathus.

Figure 2. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Figure 4. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer. Note the wider than tall torso and super long, super sharp claws.

These Jeholopterus wing images support
the narrow chord wing membrane stretched between elbow and wing tip (Peters 2002) and ignored by all subsequent workers. Note: Peters 2002 did not understand that something else made the left wing of Jeholopterus appear to have a deeper chord at mid wing. The illusion is that complete!

References
Cheng X, Wang X, Jiang S and Kellner AWA 2014. Short note on a non-pterodactyloid pterosaur from Upper Jurassic deposits of Inner Mongolia, China. Historical Biology (advance online publication) DOI:10.1080/08912963.2014.974038
Kellner AWA, Wang X, Tischlinger H, Campos DA, Hone DWE and Meng X 2010. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane. Proc Royal Soc B 277: 321–329.
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. Journal of Vertebrate Paleontology 23(3): 87A.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.

wiki/Jeholopterus

Jeholopterus wing spread

Updated March 4, 2015 with a new orientation of the Jeholopterus hind limbs and a new tail. 

Yesterday we looked at Jeholopterus, the vampire pterosaur. I also added a dorsal view of Jeholopterus to yesterday’s post to better compare it with the AMNH animated cartoon.

Today we’ll compare long and broad Jeholopterus wings to the likely shorter wings (parts are unknown) of a sister taxon from the same formation, Daohugoupterus (Fig. 1).

Figure 1. Daohugoupterus and Jeholopterus in dorsal view to the same scale. note the much smaller wings of Daohugoupterus with a similar size skull and body. Daohugoupterus may have been the 'bumblebee" of the Daohugou Formation -- technically unable to fly, but able to fly nevertheless. A rapid wingbeat probably sustained it. By contrast, Jeholopterus had broad owl-like wings, probably requiring fewer wingbeats. Note also the placement of the orbits, lateral on the left, more forward facing on the right. Not sure how to handle the hind limb filaments other than in the pattern shown here. Filaments like these may have acted to help silence the flight of Jeholopterus by absorbing sound.

Figure 1. Daohugoupterus and Jeholopterus in dorsal view to the same scale. note the much smaller wings of Daohugoupterus with a similar size skull and body. Daohugoupterus may have been the ‘bumblebee” of the Daohugou Formation — technically unable to fly, but able to fly nevertheless. A rapid wingbeat probably sustained it. By contrast, Jeholopterus had broad owl-like wings, probably requiring fewer wingbeats. Note also the placement of the orbits, lateral on the left, more forward facing on the right. Not sure how to handle the hind limb filaments other than in the pattern shown here. Filaments like these may have acted to help silence the flight of Jeholopterus by absorbing sound.

Jeholopterus had a wing area close to 4x that of the similarly-sized Daohugoupterus. This has ramifications with regard to wing beat amplitude and frequency. In order to fly more wingbeats/second are required for the pterosaur with the smaller wings. Similar difference occur between ducks and gulls.

On the same note, I’d like to direct your attention to a PBS special on owls
available online here. While owls are distinctly different from Jeholopterus, there are some analogies, as I’m sure you’ll see after viewing the program.

Like owls,
the vampire Jeholopterus would have benefited from coming in on its dinosaurian prey quietly before making its presence known. That would have happened the moment it slid those surgically-curved claws and teeth beneath soft parts of the dinosaurian hide.

Figure 2. Wing and other extra dermal membranes surrounding Jeholopterus.

Figure 2. Wing and other extra dermal membranes surrounding Jeholopterus. Note the narrow chord wing membrane preserved on both wings, just like the Zittel wing and the Vienna Pterodactylus. On the right there are some hairy plumes, not unlike those of Longisquama, which had dorsal plumes along the midline. That cannot be demonstrated with the pterosaur crushed in the dorsoventral plane, only imagined.

The extradermal membranes of Jeholopterus (Fig. 2) have been acknowledged, but never traced and modeled to see if the fibers are similar in the front and the back and what their morphology might be. Previously I assumed these were simple fibers, but that no longer seems to be the case in every case.

Here (Fig. 2) the wing membranes have a standard shape duplicated in other pterosaurs that preserved the wing membranes well. If someone else has another take on this specimen, please let me know.

And here’s a hypothesis that can never be proven:
Tianyulong, a small contemporaneous heterodontosaurid dinosaur, had long, elevated filamentous integumentary structures apparent on the back, tail and neck. These would have been ideal passive protection from vampire pterosaurs trying to alight on its back. Relatively naked giant sauropods would have made better landing zones.

References
Cheng X, Wang X, Jiang S and Kellner AWA 2014. Short note on a non-pterodactyloid pterosaur from Upper Jurassic deposits of Inner Mongolia, China. Historical Biology (advance online publication) DOI:10.1080/08912963.2014.974038
Kellner AWA, Wang X, Tischlinger H, Campos DA, Hone DWE and Meng X 2010. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane. Proc Royal Soc B 277: 321–329.
strong>Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. Journal of Vertebrate Paleontology 23(3): 87A.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.

wiki/Jeholopterus

 

The AMNH animated Jeholopterus

Updated March 3, 2015 with the addition of a dorsal view of Jeholopterus.

About a year ago
the American Museum of Natural History (AMNH) in New York City (NYC) put on a pterosaur display, both in their halls and online.

Their animated portrayal
of the Late Jurassic Chinese pterosaur, Jeholopterus, caught my eye (Fig. 1).

Figure 1. Animated GIF created by the AMNH for their web page on Jeholoopterus. Note the complete lack of an airfoil in the wing, the lack of muscles in the limbs, the presence of a uropatagium between the hind limbs, the lack of a tail, eyes set on the sides of a blockhead skull, and no care to reproduce the wide ribcage. In short, there is little that is accurate about this otherwise wonderfully animated pterosaur. And where is all the long hair that should be there?

Figure 1. Animated GIF created by the AMNH for their web page on Jeholoopterus. Note the complete disregard for its preserved anatomy, the  lack of an airfoil in the wing, the lack of muscles in the limbs, the presence of a uropatagium between the hind limbs, the lack of a tail, eyes set on the sides of a blockhead skull, and no care to reproduce the wide ribcage. In short, there is little that is accurate about this otherwise wonderfully animated pterosaur. And where is all the long hair that should be there? The animator was gifted, but the blueprint was largely imaginary.

One wonders what the animators used for reference… certainly not the fossil.
This animation lacks all the traits that make Jeholopterus unique: the up-curved jawline, the forward angled eyes, the very hairy body, the broad ribcage and belly, the deep chest, the low attachment of the wing, the large-boned limbs, the surgically curved claws, the huge feet with a very large digit 5, a longish tail and longer wings. Also lacking here is a wing with a decent airfoil section, a proper trailing edge stretched between the wing tip and elbow, large limb muscles and paired uropatagia behind each hind limb. And where does that box-like skull come from??

This is an old-school pterosaur cartoon,
lacking almost everything we know about this complete and articulated fossil. For comparison, a reconstruction is offered here (Fig. 2) based on precise tracings.

Figure 3. Click to enlarge. The Jeholopterus holotype (left) alongside the referred specimen (right). No doubt they were related, but were likely not conspecific. The one on the right was an insect eater. The one on the left was specialized for drinking dinosaur blood.

Figure 3. Click to enlarge. The Jeholopterus holotype (left) alongside the referred specimen (right). No doubt they were related, but were likely not conspecific. The one on the right was an insect eater. The one on the left was specialized for drinking dinosaur blood.

Jeholopterus had so many traits distinct from those of other anurognathid pterosaurs, that it deserves more respect than the AMNH gave it. Seems they purposely avoided describing it for what it is… a vampire pterosaur (details here). Would have been a bigger draw and a more accurate presentation had they just paid attention to the details.

The genesis of this post
came from an Ask.MetaFilter.com post on binocular vision in pterosaurs posted by Hactar, who wrote: “I am trying to find any information about binocular vision in pterosaurs. This past weekend, I went to the Museum of Natural History’s exhibition on pterosaurs. Their illustrations for Jeholopterus varied greatly in the placement of they eyes from on the sides of the head to facing forward (third picture on the page). (The second image caused me to dub it “freaky monkey pterosaur.”)  So how much binocular vision did pterosaurs have? I have found a couple of scattered references to family Anurognathus (of which Jeholopterus is a genus) having binocular vision, based on the structure of ear [sic] canals. Were these pterosaurs unique in having binocular vision, or did pteranodons and other pterosaurs have vision like a raptors instead of like a tern or pigeon? Links to academic articles are acceptable, I have confederates who can access articles for me. Please nothing by David Peters. From what I can read, his work on pterosaurs is at best somewhat wrong and generally completely inaccurate, which is a shame as he seems to be the only one who has posted anything online about this. (If the site mentions Jeholopterus as a vampire, skip it).”

Several things jump out here: 

  1. The AMNH did not edit their artwork. As noted above, one piece of artwork had lateral eyes. The other had anterior eyes.
  2. Science is a process that can be repeated by anyone. Therefore, Hactar could have taken a skull photo of Jeholopterus (or any other binocular pterosaur, like Batrachognathus), and traced the elements to arrive at his/her own skull reconstruction.
  3. If my work on pterosaurs varies from “somewhat wrong to completely inaccurate,” then I am at a loss as to how to explain the internal consistency of sister taxa that not only nest in complete resolution, but gradually evolve from one to another, apparently modeling the actual evolution of the group with stone cold logic. I also note that no one else is producing accurate tracings AND reconstructions based on those tracings. The alternative, of course, is to accept hopeful monsters, like Bennett’s anurognathid, or Andres’ hypothesis that anurognathids begat pterodactyloids, or Unwin’s uropatagium and other such fanciful hypotheses.

And like I said earlier,
this is Science, so you don’t have to accept anyone’s word for whatever you’re trying to figure out. You can find out for yourself by tracing the specimen and creating your own reconstruction. If my observations and hypotheses cannot be replicated, please send me your interpretations so they can be repaired here.

Figure 4. Jeholopterus in dorsal view. Here the robust hind limbs, broad belly and small skull stand out as distinct from other anurognathids. Click to enlarge.

Figure 4. Jeholopterus in dorsal view. Here the robust hind limbs, broad belly and small skull stand out as distinct from other anurognathids. Click to enlarge.

Don’t just repeat the propaganda ad nauseum.
The data is set in stone. Go get it and you’ll find the process rewarding.

References
Cheng X, Wang X, Jiang S and Kellner AWA 2014. Short note on a non-pterodactyloid pterosaur from Upper Jurassic deposits of Inner Mongolia, China. Historical Biology (advance online publication) DOI:10.1080/08912963.2014.974038
Kellner AWA, Wang X, Tischlinger H, Campos DA, Hone DWE and Meng X 2010. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane. Proc Royal Soc B 277: 321–329.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. Journal of Vertebrate Paleontology 23(3): 87A.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.

wiki/Jeholopterus

The Long Tail of Jeholopterus, the Vampire Pterosaur

Tradition holds that anurognathid pterosaurs had a very short tail, even a pygostyle, like that of a bird. Sure the individual bones are shorter and some become almost bead-like. Sometimes they’re very hard to see unless you spend time looking for them. They’re almost always articulated, but often preserved in a random swirl, like a beaded necklace dropped on a bed. Here are some data.

FIgure 1. The tail of Jeholopterus in situ.

FIgure 1. The tail of Jeholopterus in situ.

All anurognathid tails are gracile vestiges of once mighty robust tails, like the one attributed to Dimorphodon.

Tracing of Jeholopterus using DGS.

Figure 2. Click to enlarge. Tracing of Jeholopterus using DGS. Dorsal view of Jeholopterus based on the tracing. The tail is not particularly short when stretched to its full length, despite the reduced length of the individual caudals. The red ellipse represents a hypothetical egg shape. The abdomen was not so wide as shown here. The ribs would have had a ventral component and direction, which they do not have here. Note the right angle femoral head, ideal for parasagittal locomotion, like a dinosaur. Note the wing membrane shape, just like other pterosaurs, narrow at the elbow, able to be folded up virtually completely.

Jeholopterus in dorsal view
When a fossil preserves so much soft tissue, as Jeholopterus does, sometimes bones are hidden beneath soft tissue. This is the case with the palatal elements, which have been sloughed off to the left, beneath neck fibers. The windpipe (trachea) followed them.

The tail
Due to its many tiny elements and lack of stiffening elements, the caudal series of Jeholopterus would have been very flexible. Earlier we looked at the intraspecific communications possibilities in stiff pterosaur tails tipped with a large vane. A large vaned tail vane could also have been used like arrow fletching, keeping the tail in line with the flight path. A small, flexible beaded tail would not have had the mass to greatly affect the flight path of the anurognathid and did not sport a large vane. Keeping the tail off the ground, perhaps in a graceful curl, or weaving it like a fly-fishing line was likely selected for, perhaps as a secondary sexual trait. It seems unlikely that the tail hung limp.

The femur was held parasagittally. 
Note the right angle femoral head. This would have produced a dinosaur-like configuration while walking and would have limited horizontal extension while flying, creating, at best, an inverted V-tail, like that of a Predator drone.

Jeholopterus in lateral view. This image supersedes others in having the coracoids extending laterally and other minor modifications.

Figure 1. Jeholopterus in lateral view. This image supersedes others in having the coracoids extending laterally and other minor modifications. The long hair (shown at a minimum here) goes beyond insulation, unless it also insulated Jeholopterus from biting insects.

Different than other anurognathids
Jeholopterus has a relatively smaller head and more robust body than other anurognathids. The robust palate is uniquely designed to distribute force lines from the two front puncturing teeth back to the sides and rear of the otherwise very fragile skull. The claws are sharper, longer and more curved. The sternal complex is much smaller. The tail is longer. Metatarsal 5 is longer. So is pedal digit 5. Clearly this anurognathid is distinct from the others.

Earlier we talked about the strong possibility that it was a feeder on the same blood and wounds on dinosaur hide that insects were attracted to. As a blood-lapper, Jeholopterus would be classified as a vampire.

The modified reconstruction includes a laterally oriented coracoid, lowering the shoulder glenoid. This would direct the pectoralis muscles to pull directly medially, helping lodge the surgically curved claws medially when stepping onto dino skin for a bite.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Kellner AWA, Wang X, Tischlinger H, Campos DA, Hone DWE and Meng X 2010. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathinae) and the structure of the pterosaur wing membrane. Proc Royal Soc B 277: 321–329.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. Journal of Vertebrate Paleontology 23(3): 87A.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.

wiki/Jeholopterus

The Pterosaur Tongue

Today we’re going to delve into a soft tissue that has never been preserved in a pterosaur, its tongue. Sorry. No pix. And we’re going to do this by using a system called phylogenetic bracketing. It can only be done using a good family tree, which we have.

There are no tritosaur lizards living today. This is the clade from which pterosaurs arose. So we have to look to the Tuatara (Sphenodon), which is more primitive, and lizards, like Iguana, Gekko and Varanus which are the closest living relatives of pterosaurs.

Lizards have a well-developed tongue which they use to taste their surroundings. In some cases the tongue is so well-developed it is the primary means by which food is captured (think chamaeoleons). A lizard tongue is bifurcated (forked) and the degree of this forking depends on the phylogenetic placement of the lizard. Not so much in Iguana. Much more in snakes.

The tongue of the Tuatara is not split at the tip. And it s rather short. Here’s a pdf file describing the Tuatara tongue in detail.

So the pterosaur tongue could be split or not. The tritosaurs split from the rest of all lizards very early on, in the Permian. If it was split, the degree of splitting would not have been great. Pterosaurs didn’t need a tongue to capture or taste prey. They flew toward prey and  grabbed it with their jaws. The vampire pterosaur likely used a spongy thick tongue to lap up blood, but that’s distinctly different from most pterosaurs.

Analogs
Various birds have various sorts of tongues. The pelican has hardly any tongue at all. The woodpecker uses its tongue to probe bored holes in wood.

Then imagination takes over with a little help from tongue bones
Basal pterosaurs had large hyoids + ceratobranchials (tongue bones) which give some clues as to the size of their tongue. They also had no bottom to their jaws, which were attached only at the tip. So there was plenty of room for a tongue to be present. On the other end of the spectrum, Pteranodon skulls had only a small triangular hyoid and no ceratobranchials. Moreover a symphyseal shelf bridged the two sides of the jaws, leaving little room for a tongue. Thus, Pteranodon likely had little to no tongue, like a pelican.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

The Vampire Pterosaur Controversy: Science vs. Politics

Pterosaur expert, Dr. Mark Witton, recently rejected the concept of a vampire pterosaur, which was recently making the rounds. He also denounced and dismissed the validity of the DGS (digital graphic segregation) method in toto here at his blog, pterosaur.net.

Unfortunately, Mark provided no evidence (otherwise known as science) to back up his claims. Rather he relied only on majority support (otherwise known as politics). His points (verbatim):

  • The [vampire] idea [Peters 2003] was not peer reviewed, and it’s publication in a collection of conference abstracts is not of comparable standing to other hypotheses of anurognathid palaeoecology
  • There was never any ‘debate’ amongst pterosaur workers on this idea: it was never considered credible by qualified researchers in the first instance, and rejected outright from the start.
  • There is no evidence that Jeholopterus, or any other pterosaur, was a vampire
  • There is no ‘David Peters vs. Goliath’ story here. DP’s work is considered with the same scrutiny, not more or less, than any other piece of science. His ideas are rejected by other palaeontologists (amateur and professional alike, the only difference between many of whom is that some are paid to study fossils) because they have not stood up to this scrutiny.

You’ll note this all sounds pretty damning. You may also note, there’s no contrary evidence presented here, only a majority vote based on paradigm and opinion.

Point by point – [refer each to bullets listed above]
1. Indeed, abstracts are not considered to have equal weight as papers, but they are cited nevertheless. Ironically, every abstract I have submitted since 2003 has been rejected. I find that unusual, especially if they are not peer-reviewed. Having peer-review does not make a paper perfect and unassailable. Many papers have only a few to several errors, which is why pterosaurheresies.com exists and why several papers written by several other paleontolgists “reexamine” and “reappraise” many fossils. Re: anurognathid palaeoecology: The Bennett (2007) paper on the flathead anurognathid is chock-full of errors and inventions, all listed here.

2. “Never any debate” [on the vampire concept]? That means, of course, that my voice apparently doesn’t count as one side of the debate (despite several published papers) and I am not a “pterosaur worker.” Mark’s comment, “rejected outright from the start,” should also raise an eyebrow. “Outright from the start” means, of course, there was no scientific inquiry, no patient duplication of the methods on Jeholopterus and certainly no counter-evaluation. Certainly no competing interpretations of Jeholopterus have ever been sent to me for comment. So, again, where’s the science here? Where’s the discussion?

I want my errors to be pointed out. Where they have been, I appreciate it and make whatever changes are necessary. Do others ever acknowledge errors? Not if I point them out (at least so far). I also give credit where credit is due, even when pointing out minor errors, as in by reexamination of pteroid articulation in pterosaurs (Peters 2009) in which I pointed out achievements and errors made earlier by Dr. Bennett.

3. The comment, “There is no evidence…” followed by any statement whatsoever is exactly what one hears in creationist arguments against evolution. That’s a shame. It would have been more scientific if Mark would have presented another interpretation, starting with an in situ tracing that we could argue about point by point. I only came up with the vampire concept after examining every aspect of Jeholopterus, including the palate, which is uniquely designed to transmit impact forces to the sides and rear of the skull and the claws which were uniquely hyper-curved like surgical needles for adhesion.

4. The comment “His ideas are rejected by other paleontologists…because they have not stood up to this scrutiny.” That’s a pretty broad brush. Does that mean ALL my ideas? Sounds like it. Even those that were published in peer-reviewed journals? And when it’s one against the rest, as Mark defined it, it is “David vs. Goliath,” by definition. If they get to referee my papers and I don’t get to referee theirs’, by definition that is an imbalance in power.

I will confess to making many mistakes in science. That happens to everyone, especially with pterosaurs! New data comes in and old interpretations need updating and revising. In fact, I corrected a tiny palate element on Jeholopterus just this morning because I realized it had probably gotten knocked off its mooring during taphonomy because it did not match the connection seen in other sister taxa.

I posted a considerate response to Mark’s comments on Pterosaurnet.net. Let’s see if gets approved and makes a difference to Mark’s perception of this impasse.

My response in brief:
In the nine years since the Jeholopterus abstract no one else has re-interpreted the skull and sent it to me for discussion.

Mark prefers the Bennett (2007) model of the flathead anurognathid (a sister taxon) with errors detailed here and here.

Jeholopterus in lateral view. This image supersedes others in having the coracoids extending laterally and other minor modifications.

Figure 1. Jeholopterus in lateral view. This image supersedes others in having the coracoids extending laterally and other minor modifications.

I present evidence that passes many tests including symmetry, fit within a reconstruction and phylogenetic similarity to sister taxa. I hope someone who disagrees with my reconstructions can do the same. Certainly Bennett’s (2007) interpretation of his anurognathid, the one preferred by Dr. Witton, does not pass these tests. Bennett (2007) himself admits to making up some of the elements he was unable to find using traditional observational methods.

Bottom line: Hey, facts are facts.
Both sides should present facts, not opinions. It would have been better if Mark showed, “Here’s why Jeholopterus is not a vampire.” This business about, “no evidence,” doesn’t help at all.

References
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures.
Journal of Vertebrate Paleontology, 23(3):87
Peters D 2009. A Reinterpretation of Pteroid Articulation in Pterosaurs – Short Communication. Journal of Vertebrate Paleontology 29(4):1327–1330, December 2009

Pterosaur.net

Pterosaur Fingers – Part 1, Basal Taxa and Dimorphodontids

Most pterosaur workers pay little attention to the hands of pterosaurs. That’s unfortunate. Here many traits, including the relative lengths of the metacarpals and manual phalanges, were found to be as distinctive and phylogenetically informative as the relative lengths of the metatarsals and pedal phalanges reported in the catalog of pterosaur pedes (Peters 2011). In today’s blog we’ll examine the hands of a basal clade of pterosaurs (Fig. 1), highlighting only a few outstanding traits and ignoring the wing finger. We’ll continue the examination of other pterosaur fingers in later blogs. Today it is not important which way the fingers flexed, but if you’re interested, look here.

Pterosaur fingers

Figure 1. Pterosaur fingers. Click to enlarge. Red arc arrow indicates twisted phalanges to show ungual shape. Otherwise blue shapes indicate ungual shape.

Basal Pterosaurs and Dimorphodontids
The configuration of the basal pterosaur manus reflects its fenestrasaur ancestors, like Cosesaurus, Sharovipteryx and Longisquama. The latter two and perhaps all three were derived late survivors of the original splits that produced pterosaurs. The elongation (asymmetry) of the lateral metacarpals and lateral digits goes back to a basal tritosaur lizard, Huehuecuetzpalli. The trend in several pterosaur lineages was toward a greater symmetry in the metacarpals and (less often) the digits.

MPUM 6009 – The manus of the most primitive pterosaur(Fig. 1) was relatively smaller than that of its phylogenetic predecessor, Longisquama and distinct in terms of metacarpal and phalanx proportions. In MPUM 6009 metacarpal 1 was ~60% the length of metacarpal 3, which was just shorter than metacarpal 4. Metacarpal 3 was more than half the diameter of metacarpal 4. Manual 1.1 was twice the length of m2.1. Digits 1 and 2 were subequal and shorter than digit 3.

Austriadactylus – In both of the pterosaurs attributed to Austriadactylus metacarpal 1 was relatively longer. Metacarpal 3 was more gracile and as long as metacarpal 4. Manual 1.1 was relatively smaller. Digit 2 was longer than digit 1.

GLGMV-0002 – This basal dimorphodontid had a more robust metacarpal 4. Manual 3.2 was shorter.  Digit 3 was relatively shorter and shorter than metacarpals 3 and 4.

Dimorphodon micronyx – The metacarpals were all relatively shorter and digit 3 was longer creating more asymmetry in relative finger length.

Preondactylus -The phalanges of digit 3 were more similar in length.

Peteinosaurus – Metacarpal 4 was more gracile as were the fingers and unguals. Digit 3 was 50% longer than digit 2.

MCSNB 8950 – Longer metacarpals appear. Manual 2.1 was longer. Manual 3.2 was shorter.

IVPP embryo – The IVPP embryo comes form the Early Cretaceous and thus represents a late-surviving representative of a Late Triassic/Early Jurassic radiation. Metacarpal 4 was longer and more robust, and wider than mc1-3 combined. Metacarpals 1-3 were more gracile and essentially subequal in length. Digits 1-3 were more gracile and relatively shorter and shorter than the metacarpus. The penultimate phalanges were subequal.

Dimorphodon? weintraubi – Metacarpal 4 was not much more robust than mc1-3. While mc1 remained slightly shorter than mc3, all three metacarpals were aligned. The digits were longer than the metacarpus. The digits were less asymmetric. Manual 3.2 was no longer than wide.

Anurognathids

Dendrorhynchoides – Metacarpals 1-3 remained robust and subequal. Digits 2 and 3 were subequal. Manual 2.1 and m 3.1 were subequal and short.

The Flathead anurognathidSMNS 81928) – Here metacarpals 1-3 were aligned, but mc1 was the longest in the set. Manual 2.1 was as long as m3.1+m3.2 and aligned with m1.1. Manual 3.3 was longer than m2.2.  Digits 2 and 3 were nearly subequal. Manual 2.1 was subequal to m3.1+m3.2.

Anurognathus ammoni – Metacarpal 4 was more robust and shorter such that the pulley joint was half the length of metacarpal 4. Metacarpal 4 was slightly shorter than mc1-3, which were subequal to each other. Manual 2.1 was half as long as m3.1. Manual 2.2 was subequal to m3.3. The unguals were nearly as long as the penultimate phalanges.

CAGS IG 02-81 – Manual 2.1 was subequal to m3.1 in this pterosaur attributed to Jeholopeterus. Metacarpal 4 was not so robust, similar to mc 1-3. Manual 3.2 was shorter than wide.

Jeholopterus – The metacarpus was relatively longer than in the CAGS specimen. Metacarpal 3 was the shortest. Metacarpal 1 was subequal to mc4. Digit 2 was slightly longer than digit 3. Distinct from other anurognathids and other pterosaurs, the unguals were narrow, strongly curved and elongated like surgical needles. This trait, among others, led to the hypothesis of vampirism in this taxon.

Batrachognathus – Metacarpal 4 was short and very robust with a broader base than in Anurognathus. Metacarpals 1-3 were shorter than mc4. Digits 1-3 were subequal. Manual 3.2 was a disc. Manual 1.1 was longer than m3.2 and m4.3. The unguals were shorter than in Jeholopterus.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification. Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605