Methinks it is like a sauropsid

Eugene McCarthy, the author of that crackpot stabilization theory, has discovered my review and is now making a noise on twitter. He's gone from thanking me profusely for mentioning him, to whining that I stole his figures, to complaining that I don't understand his theory at all, all in the last 24 hours.

But here's the fun part. Recall that one of his bizarre claims is that whales did not evolve from terrestrial artiodactyls, but from mosasaurs, mesozoic marine reptiles, instead. But the anatomy shows that mosasaurs are derived squamates, reptiles, with a completely different skeletal organization than a mammal. This has attracted the attention of Darren Naish and Tom Holz, fully qualified comparative anatomists and paleontologists, who actually know a great deal about the structure of these animals, and are giving him a spectacular ass-whooping. Browse it on Twitter.

The basis of his claim is that mosasaur teeth "look like" sperm whale teeth. That's not a good criterion, and it's not true; as has been pointed out to him, basal mosasaurs are pleurodont (that is, the teeth are fused to the inner side of the jaw bone), not socketed as are sperm whale teeth. He's also now claiming that mosasaurs swam by vertical motions of their tails, like whales…but he's citing articles with poor comprehension. The cited articles show evidence that mosasaurs propelled themselves with axial motions of the tail, which is a far more general statement; they moved by sweeping their tails like oars, but it says nothing about vertical vs. horizontal undulations.

So I went back to McCarthy's book to see how he backed up this ridiculous claim. He doesn't. He cites Pieter Camper, an 18th century anatomist, as proposing the idea that whales are related to mosasaurs. His critics are citing contemporary and detailed papers. This, however, is really the totality of McCarthy's argument:

The varanid theory was based on Adriaan Gilles' assertion that certain skeletal characters found in mosasaurs are not found in modern whales. However, a glance at figures 9.4 and 9.5, will convince most readers that mosasaurs have much in common with early whales. Certainly, they have far more in common with whales than does the late Cretaceous terrestrial insectivore traditional theory posits as the common ancestor of whales and all other placental mammals (it should be emphasized that all of the various forms classified as mosasaurs, too, are of late Cretaceous age). They are also far more similar to whales than is Pakicetus. One would not expect the ancient ancestors of whales to have every characteristic of modern whales. Their dissimilarity with respect to a few minor bony traits should not be allowed to obscure the well established fact that mosasaurs were huge, whalelike, air-breathing animals with whalelike teeth and that they had the same sort of prey as modern whales.

The referenced figures are grainy, low resolution images that do not do an adequate job of displaying the structures. The "dissimilarity with respect to a few minor bony traits" is trivialized; these are actually substantial differences in the arrangement and number of bones in the skull, where the mosasaur displays a fairly standard reptilian pattern and the whales show a mammalian pattern. They only look alike if you don't look at all closely. How can you say that the jaw joint or the auditory complex of a whale look anything like that of a reptile? Only by not looking.

His other argument is that it would take fewer evolutionary changes to transform a mosasaur into a whale, than a shrew into a whale. This is nonsense. Turning a reptile into a mammal requires a major reorganization of the bones of the skull, and further, requires that those shifts exactly mimic the pattern found in other mammals. There is no reasonable way to accomplish that. Again, the basis of his entire argument is a complete ignorance about the anatomy!

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He made quite a good run for the Presidency in 1968 though.

Every few years, someone sends an article to a journal like "Paleobiology" or "Science" with the claim to have "discovered" that humans evolved from dinosaurs (or somesuch). I've seen some of these manuscripts (which, not surprisingly, get rejected). It's sad to see people who imagine that they support science reasoning like creationists ("it looks that way, so that's how it must be")

By Christine Janis (not verified) on 23 Jan 2013 #permalink

PS. "Turning a reptile into a mammal requires a major reorganization of the bones of the skull, and further, requires that those shifts exactly mimic the pattern found in other mammals. "

What about the middle ear????

By Christine Janis (not verified) on 23 Jan 2013 #permalink

The middle ear is part of the skull. Or, anyway, 2 of the 3 bones mammals have in there are derived from the skull (including the lower jaw), and the 3rd may count as well (matter of definition).

By David Marjanović (not verified) on 24 Jan 2013 #permalink


By Atlantic Devel… (not verified) on 25 Jan 2013 #permalink