Pterosaur Heresies and “Pterosaurnet” (NOT Pterosaur.net): please die
Today we’re going to discuss the blogs of two people who fail at biology in every conceivable way: David Peters (famous example already) and…some guy who probably doesn’t even have a name. Whatever, its not like I am going to debate their identity or anything, just what they present.
David Peters in particular has been notable for being a failure at biology since 2006, and since how nobody acknowledges him as a living being, I would not care the least if not for the fact that his garbage has been contaminating Google. Hence, here’s my take at his pseudo-scientific arguments:
A review of his whining against quadrupedal launch in pterosaurs (you can find the adress easily)
We start the article by giving away the sources of his insanity:
The idea of bipedal pterosaur running downhill into a headwind was floated by Chatterjee and Templin (2004), but had few takers. Bennett (1997) imagined the first pterosaurs leaped with their hind limbs into flight. Padian (1981) imagined they ran first.
This is pretty much the bulk of the sources he utilizes during the article. Seriously, they’re all the indication that he uses to explain bipedal locomotion and take off in pterosaurs; the rest is just nonsensical speculation. Perhaps it never occured to him that the lattermost source is no longer taken seriously by anyone, considering that the idea that basal pterosaurs engaged in bipedal running has been considered the object of ridicule since the 90’s and all, for very good reasons. Even today it is generally thought birds evolved flight by arboreal methods, either gliding or WAIR (or both), and birds are way more likely to have evolved from ground dwelling animals that pterosaurs! I have not read the paper y Bennett, but the idea that pterosaurs evolved flight by arboreal leaping is possible given the long hindlimbs of Dimorphodon. However, that does not mean pterosaurs were bipedal; many arboreal mammals use their hindlimbs to jump, but they sure as hell are not bipedal! And bats use their forelimbs to take off, despiste the fact that other gliding mammals use their hindlimbs, so you can clearly see that switching can occur!
“Thus, Habib reasoned, since all pterosaurs were quadrupeds (this is questionable, see below), they must have employed their strongest limbs, their wings (this is also questionable, see below), “
IT. IS. NOT. QUESTIONABLE!!! The only way it is questionable is because you somehow seem to think that the weak hindlimbs of pterosaurs could support the animal in a penguin like position that goes against the laws of physics thanks to the absurdly huge forelimbs. And you might think that I am being unreasonable, but you’ll see why that harlot does not seem to abide by the physics of this universe.
“Of course, evidence for either the Habib (2008) hypothesis or the heretical bird-style take-off would have to come in the form of take-off tracks. Unfortunately we don’t know of any such tracks. We only know of one landing trace (Mazin et al. 2009, Figure 3), which came in feet first. So let’s examine each of the precepts of Habib’s hypothesis and see if any problems arise.”
You admit it is a landing trace, hence it is not a problem because the animal is landing, not walking normally nor taking off. It is generally agreed that the hindlimbs would have been necessary for landing, otherwise the animal would crash violently against the ground. The exact method on which pterosaurs landed is not entirely well known, but saltatorial motions have been suggested. The animation David Peters presented had the animal just land directly on the path and walk as if nothing happened, which is doubtful at best. Perhaps most importantly, however, is that several quadrupedal pterosaur footprints have been found, so bipedal locomotion was defenitely not present.
“While most pterosaurs had a larger diameter humerus than femur, not all did. Basal pterosaurs up to, but not including, Carniadactylus and Eudimorphodon had a humerus no thicker than the femur. The same held true for a few Rhamphorhynchus specimens, Sordes, some Pterodactylus specimens and at least one germanodactylid. The flightless pterosaur had a tiny humerus. Some pterosaurs, such as Zhejiangopterus andFenghuangopterus had a much shorter humerus than femur. Thus the femur in these taxa would have had much more leverage, travel and associated muscles to launch the pterosaur further and higher. Why did some pterosaurs have a large diameter or longer humerus? I don’t know. I can’t see a clear phylogenetic pattern yet.”
I would state that it is very suspicious that he only offered skeletals instead of fossil specimens, but I figured out it was the best option you had, seeing as even I would would not like to make a fool out of myself posting images of fossils that contradict the delusional statements. Perhaps more amusing, though, is that several of the skeletals contradict what he said. Appearently even his drawing skills are against him. (Incidently, it took a while for the pictures to show up in my computer. Even my sentienceless machine is against such abominations!)
“Habib (2008) reports the forelimb bones were more than strong enough. Were they long enough? The answer seems doubtful if one compares the skeleton of our greatest living leaper, the kangaroo with that of a pterosaur (Figure 4). Despite having five muscle groups from pelvis to toe contracting in a coordinated series, kangaroo initial leaps raise the toes only to the heights of the ankles. By contrast, pterosaurs had only their elbows and wrists to extend and they could extend their elbows a relatively shorter distance, not counting the effect of the propatagium, which in birds and bats prevents exactly this sort of overextension of the elbow. Even the vampire bat leaves 15-20 degrees of flex at the elbow during takeoff.”
Considering that kangaroos lack pneumatic bones and airsacs, I would question how apropriate the comparation would be, not to mention that the hindlimb structure of a macropodid is much different from the forelimbs of an ornithocheirid, not only in actual appearence, but in function; kangaroos are adapted to long distance saltatorial locomotion, while pterosaur forelimbs are adapted to quick launches. It is very obvious that the initial launch styles are different, considering that the limbs don’t even remotely resemble each other. Furthermore, David Peters is deliberately lying on this paragraph, as he is not only giving a much more restricted range of forelimb motion than what was actually true for pterosaurs, but he ignoring that fact that, unlike vampire bats, pterosaurs have long metacarpals, which actually allow further the capacity of the overextension of the elbow. Furthermore, bats also have patagia, hence stating that it blocks the capacity for overextension is quite a quite obvious form of intellectual dishonesty.
The following paragraph bases itself on the evolutionary pathway of pterosaur flight, which at the very best is speculative and at worst is mind numbing shit. Unfortunately, as you might have guessed, it’s the later, because he claims that pterosaurs followed the evolutionary path he always claimed: that pterosaurs evolved from a Sharovipteryx abomination that in turn evolved from mutant lizards. Nevermind that Sharovipteryx was clearly not a lizard because it has little to no anatomical similarities to squamates and that instead it appears to have been a basal archosauromorph, but then again David Peters’ view of diapsid classification is a twisted nonsensical bunch of speculations that largely ignore convergent evolution and several anatomical differences. Furthermore, Sharovipteryx is not considered a biped, hencing ruling out the absurd depictions of it standing on its hindlimbs like a mutilated theropod asking for the mercy of death. That said, pterosaur evolution is a fascinating topic. We do know that they are related to archosaurs, but whereas they are the sister taxa to dinosaurs and their relatives or forms more basal than pseudosuchians it is not known. A recent paper did consider them related to drepanosaurs, which might indicate that they evolve from Sharovipteryx like forms after all, but then again we don’t know if Sharovipteryx was related to drepanosaurs or not.
Then again, as I stated previously, “switching” did happen with bats, so it renders the argument of origin a dumb one (not to mention that the “examples of bipedal pterosaurs” he cited were actually quadrupedal). And that leads us to the next paragraph, which concerns itself on just how pterosaurs developed from bipedal launchers into quadrupedal launchers. As you can imagine, he ignores that such probably occured in the arboreal early non-pterodactyloid pterosaurs rather than on derived terrestrial pterodactyloids. Neat.
Next he makes up bullshit regarding the fact that wing fingers would stall quadrupedal take off. I think that he forgot that the base of of the pterosaur wing finger has a role in supporting the weight of the body alongside the clawed fingers (Darren Naish did in fact suggest that the wing finger and the associated metacarpal play a larger role at supporting the body’s weight than the remaining fingers), while vampire bats don’t do so.
The following paragraph is another of his ridiculous misinterpretations based on fossil pics rather than actual close up analysis, so I am not going to even bother to discuss it.
Finally, we analyse the final section of his delusional stupidity:
“Of course, modern stilts, flamingoes and storks do very well in their bird-style launches, even with their “stilt”-like leg bones. Bending forward at the hip would have positioned the wings at the appropriate angle of attack (see below).”
Regardless, one important aspect of David Peters’ essay that he conveniently forgets is that bone density is very important. In birds, the femur is always far more dense than the humerus, as is fitting of an animal that relies exclusively on it’s hindlimbs to take off. Perhaps more obvious, however, is the fact that birds have absurdly long metacarpals, something pterosaurs lack.
“It is important to note that bird legs and pterosaur legs had one fundamental difference: bird femora are not only tucked close to the body they are constrained by torso skin from moving much. So bird strides really begin at the knee. Birds elongate their metatarsals to produce yet another flexible leg section (the so-called “backwards knee”). By contrast, pterosaur femora swing from the hip and they all had relatively short metatarsals. Thus any mathematical comparisons, like those performed by Habib (2008) between the two types of flyers are going to be affected by this basic difference.”
Oh, son of a bitch!
The only sources offered in the DP article I just spat on are the ones mentioned at the beginning, that concern the apseculation on early pterosaurs adquiring the capacity to fly, and those that involve the pterosaur landing trackway and the pterosaur quadrupedal launch. Therefore, most of what is stated on the article has no basis on anything except for misinterpretations of availiable evidence.
To be fair, I am guilty of this as well, so I won’t criticise DP for this. I will, however, criticise the “Pterosaurnet” imbecile for that.
“Pterosaurnet”: when people without functional brains try to mimic respectable sites
Unfortunately, David Peters is not the only nutjob who wanders around on the net. An even more insane wacko has emerged lately, owner of the site “Pterosaurnet”.
This imbecile, a truly abhorrent harlot who obviously tried to copy the fabled site Pterosaur.net, has even less functional neurons than David Peters. He/she suggested the most obviously stupid thing to be imaginable: that birds are derived pterosaurs, and not coelurosaur dinosaurs. This wouldn’t bother me so much (after all, most people are smart enough to know how utterly stupid that sounds), if s/he weren’t around sites with actual experts bothering them constantly with this bullshit. And, while David Peters at least recognises fossil evidence (despiste misinterpreting it horridly), this person/thing doesn’t even pretend to know anything about this topic; it just picks parts of Wikipedia that haven’t been updated and quote mines them into looking like they support the “birds are pterosaurs” shit.
Also seems to enjoy neutrino based jokes. How odd.