tag:blogger.com,1999:blog-38902250.post3923301308294761519..comments2023-10-25T04:04:15.348-07:00Comments on When Pigs Fly Returns: There's No Such Thing as a "Mammal-Like Reptile"Zachhttp://www.blogger.com/profile/08692080707969333711noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-38902250.post-41098900968029884492009-06-07T10:38:39.430-07:002009-06-07T10:38:39.430-07:00No, but there is a bear-dog (Amphicyon)!No, but there is a bear-dog (<i>Amphicyon</i>)!Zachhttps://www.blogger.com/profile/08692080707969333711noreply@blogger.comtag:blogger.com,1999:blog-38902250.post-21968928812125020512009-06-07T08:50:06.214-07:002009-06-07T08:50:06.214-07:00Hey i gotta question is there a such thing as a do...Hey i gotta question is there a such thing as a dog cat??<br />-Dani age 11Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38902250.post-81353784052478041382007-05-02T18:43:00.000-07:002007-05-02T18:43:00.000-07:00Hmm...unscaly, amphibian-like skin? That's just pl...Hmm...unscaly, amphibian-like skin? That's just plain hard to imagine. I demand a graphical representation! By Saturday! And Dracorex IS a derived pachycephalosaur, dammit, it's not a coelocanth!<BR/><BR/>Oh, and stegosaurs totally got it on like ducks. And if you've been checking out Naish's blog lately, you know just how terrifying that prospect can be.Zachhttps://www.blogger.com/profile/08692080707969333711noreply@blogger.comtag:blogger.com,1999:blog-38902250.post-10207684392696979472007-05-02T18:07:00.000-07:002007-05-02T18:07:00.000-07:00Phylo bracketing:I don't think you have a case, he...Phylo bracketing:<BR/><BR/>I don't think you have a case, here. Bracketing (by implication) indicates by extents or extremes, and the feature being interpolated resides with an animal sitting <I>between</I> the brackets.<BR/><BR/>Or you've taken mammals with scaly skin (such as pangolins) and made their integument very distant and highly derived models of scaly skin of the kind seen in reptiles.<BR/><BR/>I'll concede that's possible, but the terms <I>superficial similarities</I> and <I>analogous structure</I> haunt me.<BR/><BR/>Generally, I've repudiated the scaly integument supposition for protomammals, favoring a more primitive-derived-from-an-ambiphious-ancestor-<I>unscaly</I>-skin skin.<BR/><BR/>Additionally, seems like this would be a good point to push if we'd like protomammals to stop being called mammal-like reptiles. (Unless, of course, an impression of integument comes to light. Dang. I was really excited there for a minute.)<BR/><BR/>"What more do you need?"<BR/><BR/>Something testable?<BR/><BR/>Again, since definitions are arbitrary, there will be taxa that darken the bright lines of taxonomic purity. For them, new categrories will have to be created. Close to, but not of, the established definitions.<BR/><BR/>Dracorex: There are many examples of taxa largely considered "primitive" which are alive and well today, from the extant aquatic examples of Sarcopterygiian fishes (e.g. Coelacanths) through proto-tetrapod lungfishes. Though in fact each of these groups possess derived characteristics that reveal some distance between their extinct coutnerparts, they are still considered "primitive." I see no reason not to apply this principle to taxa much more closely related to one another.<BR/><BR/>(Stegosaurs got it on like ducks. If that isn't nightmare fodder, I'm not doing my job <I>right</I>.)Dicing with Dragonshttps://www.blogger.com/profile/03132972790091524968noreply@blogger.comtag:blogger.com,1999:blog-38902250.post-86179829593835634762007-05-02T14:39:00.000-07:002007-05-02T14:39:00.000-07:00Harsh toke, man. Well, there are some skin impress...Harsh toke, man. Well, there are some skin impressions from critters like Scutosaurus, and they appear to be scaly. I guess I'm merely using PHYLOGENETIC BRACKETTING to guess that the first synapsids had scaly skin. <BR/><BR/>And as for the Silesaurus thing, as you're probably aware from my previous postings, I'm convinced that it's a primitive ornithischian. Because it seems to have a few primitive characters (closed acetabelum, two sacrals), Dzik's cladistics posit it as a late-blooming ornithodir. Never mind that Saturnalia has a closed acetabelum and Eoraptor (and Herrerasaurus maybe) have two sacrals. And Silesaurus has a freakin' predentary. What more do you need?<BR/>As for Dracorex, cladistics would position it as the most primitive pachycephalosaur, but as Bakker points out, its end-Cretaceous age as well as its many-spined noggin suggest a close affiliation with Stygimoloch. It's lack of dome confuses the cladistic analysis, when that feature is really just a reversal in response to sexual selection (horns over dome).<BR/><BR/>So that's what I meant by that.Zachhttps://www.blogger.com/profile/08692080707969333711noreply@blogger.comtag:blogger.com,1999:blog-38902250.post-62770997466504648252007-05-02T12:59:00.000-07:002007-05-02T12:59:00.000-07:00Great essay. Minor points only:"Sure, there are t...Great essay. Minor points only:<BR/><BR/>"Sure, there are times when you have an animal like Silesaurus or Dracorex where cladistics actually impedes forward momentum,"<BR/><BR/>You know this how?<BR/><BR/>"and both groups had scaly skin."<BR/><BR/>Really? We have integument impressions for protomammals? I was unaware of this! Details, man! Spill me the details!<BR/><BR/>And this isn't a technical pick, but a grammatic pick:<BR/>"Because true reptiles modified their skulls in one way, and synapsids modified their skulls in a different way."<BR/><BR/>Say, rather, that reptile skulls were modified (or evolved) along one line, and synapsid skulls evolved along a different way.<BR/><BR/>I have the same response whenever workers use the term "design". There is no design in nature, naturally, and that's not what they mean, but they should <I>say</I> what they mean, rather than use lazy terminology like "design" where they mean "evolved."Dicing with Dragonshttps://www.blogger.com/profile/03132972790091524968noreply@blogger.com