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- The [vampire] idea [Peters 2003] was not peer reviewed, and it’s publication in a collection of conference abstracts is not of comparable standing to other hypotheses of anurognathid palaeoecology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 I find that unusual, especially if they are not peer-reviewed.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.
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.
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