tag:blogger.com,1999:blog-3248412803814730250.post5766577351708745017..comments2024-03-17T01:48:59.504-07:00Comments on The Theropod Database Blog: Chiappeavis is just another PengornisMickey Mortimerhttp://www.blogger.com/profile/08831823442911513851noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-3248412803814730250.post-88484424204189336592016-03-03T13:25:12.802-08:002016-03-03T13:25:12.802-08:00Well, uh, have you read Jingmai O'Connor's...Well, uh, have you read Jingmai O'Connor's response to this analysis? If you haven't, I warn you: it's pretty nasty.Anonymoushttps://www.blogger.com/profile/10195879143173508349noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-35221762460169548202016-01-17T08:40:20.643-08:002016-01-17T08:40:20.643-08:00I just read the update. "Median" means &...I just read the update. "Median" means "<b>in</b> the sagittal plane", so there can be only one.David Marjanovićhttps://www.blogger.com/profile/00233722577300632805noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-44057824622926275032016-01-16T09:20:18.518-08:002016-01-16T09:20:18.518-08:00Do you mean monospecific genera?
If so, there are...Do you mean monospecific genera?<br /><br />If so, there are two reasons.<br /><br />The first is cultural. <b>We don't see genera in the real world</b>; genera don't exist outside of taxonomists' heads. Therefore, dinosaur paleontology has a long tradition of using the genus as the unit of biodiversity; genera with two or more species are typically split after a few decades or see their species synonymized. Because genus names are unique, they are used to refer to species; "<i>Tyrannosaurus</i>" is talked about rather than "<i>T. rex</i>". Mickey's complaint isn't that the pengornithid species shouldn't be split into as many genera; it's that they should all be referred to a single species.<br /><br />The second is that the fossil record is neither all that complete nor all that well known; a random sample of a few species will likely not turn up species that an ornitho-neontologist would classify into the same genus.David Marjanovićhttps://www.blogger.com/profile/00233722577300632805noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-61009973852322371182016-01-13T14:22:20.234-08:002016-01-13T14:22:20.234-08:00I have always found it strikingly odd that all Chi...I have always found it strikingly odd that all Chinese Jehol and related birds comprise monophyletic genera - in clear contradiction to what one see in the real world. So i look forward to the time when enantiornithines etc are revised to actually document the real generic diversity and identify the multiple synonyms that there are now.Anonymoushttps://www.blogger.com/profile/00543980718836375589noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-55576348359581314872016-01-11T19:02:40.205-08:002016-01-11T19:02:40.205-08:00Yes, good point - O'Connor &c found eviden...Yes, good point - O'Connor &c found evidence of a 'pope's nose' in Feitianus. Makes sense - the rectricial bulbs could help move around the display feathers.Timhttps://www.blogger.com/profile/17837037454015036429noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-58511595738665502212016-01-11T02:21:41.558-08:002016-01-11T02:21:41.558-08:00Good point. I had forgotten that about Eopengorni...Good point. I had forgotten that about Eopengornis.<br /><br />We do have probable preserved retricial bulbs in the enantiornithine Feitianius, which besides the long paired retrices of most enantiornithines, has vaned feathers over three times as long as the pygostyle. Do those constitute a tail fan? The pygostyle's pretty standard for enantiornithines. But no, I'd say don't treat characters as correlated unless one logically forces the other.Mickey Mortimerhttps://www.blogger.com/profile/08831823442911513851noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-24712409727533590822016-01-10T15:04:04.511-08:002016-01-10T15:04:04.511-08:00Eopengornis has no tail fan (and by implication, n...Eopengornis has no tail fan (and by implication, no rectricial complex), so to me Fig S1A (recovering a monophyletic Pengornithidae) would imply that this feature was lost *twice* in Enantiornithes: (1) in the Eopengornis line of Pengornithidae, (2) the clade comprising the rest of the Enantiornithes (= sister clade to Pengornithidae in S1A). <br /><br />O'Connor et al. make the point that the 'rectricial complex' morphology comprises a number of features, in both the skeleton (pygostyle morphology) and integument (rectricial morphology and arrangement). (There's also the rectricial bulbs, but they're invisible in the fossil record.) So should these characters be treated as correlated?Timhttps://www.blogger.com/profile/17837037454015036429noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-42530507001334161482016-01-08T02:21:17.992-08:002016-01-08T02:21:17.992-08:00Yup, I believe both are synonyms (though Parapengo...Yup, I believe both are synonyms (though Parapengornis has more valid differences from the Pengornis holotype at least). And yes, if S1E is correct, the loss of the tail fan could have happened just once. The same goes for S1A, where pengornithids are monophyletic, but basal within Enantiornithes. But the differences between the equally parsimonious trees in S1A and S1B show that like mine and Cau's matrices, O'Connor's matrix doesn't strongly support many relationships within Enantiornithes. So I wouldn't put much trust into any given topology or distribution of any given character like retrical morphology.Mickey Mortimerhttps://www.blogger.com/profile/08831823442911513851noreply@blogger.comtag:blogger.com,1999:blog-3248412803814730250.post-15724345878416083792016-01-06T21:42:07.857-08:002016-01-06T21:42:07.857-08:00So you're proposing that both Chiappeavis AND ...So you're proposing that both Chiappeavis AND Parapengornis may be junior synonyms of Pengornis? If so, and if Pengornithidae is paraphyletic (as in Fig. S1E), then it suggests a loss of the aerodynamic tail fan (associated with rectricial bulbs as the "rectricial complex") could have occurred just once at the base of the Enantiornithes.Timhttps://www.blogger.com/profile/17837037454015036429noreply@blogger.com