Polyphyletic

Nick, Actually Mononykiformes are getting farther away from Alvarezsaurus in my classifications. Alvarezsaurus was just outside of my AVES, and now is not far inside (a small jump), whereas Mononykiformes have taken a huge jump over all the caenagathiforms, the omnivoropterygiforms, longipterygiforms, all the enantiornitheans, and patagopterygiforms (whether they should have jumped over chaoyangiforms as well needs more study, but I can make that minor adjustment if need be). Mononykiformes are far too derived to be closely related to Alvarezsaurus. They have narrow (elongated) sterna that are keeled, fibula not contacting the calcaneum, various features of the astragalocalcanea (spelling?), derived femoral trochanter positions, large hypapophyses on the anterior dorsals, and so on. And they are hyperarctomets, quite unlike Alvarezsaurus. I agree with Mickey that an Alvarezsaurus-like form evolved into mononykiforms, but that a whole bunch of major clades split off in between them, during which time much evolution occurred (i.e., they're very polyphyletic). I have already criticized the homoplastic characters (that supposedly unite 'Alvarezsauria' back when I was still on DML (see the DML archives when their 'search function' is working again). In particular, the procoelous caudal vertebrae (and sacrals) of mononykiformes are much more like those of Patagopterygiforms, than those of Alvarezsaurus. And the procoelous caudals of titanosaurs show that such a character can evolve independently in unrelated forms. Alvarezsauria is DEAD, DEAD, DEAD, as far as I am concerned. I pronounced it dead quite some time ago, but now I am increasingly inclined to nail the coffin shut and bury it for good. R.I.P. I don't care if everyone from Larry Martin to Mary Norell thinks it's a clade!!! That it is extremely popular with both BANDits and BADD doesn't make it right. A Flat Earth was once a popular concept as well. What we need to do now is look for the real Alvarezsaurus relatives among the dromies or related basal 'birds'. That is why I have preliminarily assigned Alvarezsaurus to Order Archaeopterygiformes. If it doesn't belong there, I might have to put it back outside of AVES with the therizinosaurs (present sister group of my AVES). We shall see.

That should read 'Mark' Norell, not Mary Norell. I should learn to proofread better. **************************************************** Group: sci.bio.paleontology Date: Tue, Oct 1, 2002, 6:32pm

Nick,           Actually Mononykiformes are getting farther away from Alvarezsaurus in my classifications. Alvarezsaurus was just outside of my AVES, and now is not far inside (a small jump), whereas Mononykiformes have taken a huge jump over all the caenagathiforms, the omnivoropterygiforms, longipterygiforms, all the enantiornitheans, and patagopterygiforms (whether they should have jumped over chaoyangiforms as well needs more study, but I can make that minor adjustment if need be).               Mononykiformes are far too derived to be closely related to Alvarezsaurus. They have narrow (elongated) sterna that are keeled, fibula not contacting the calcaneum, various features of the astragalocalcanea (spelling?), derived femoral trochanter positions, large hypapophyses on the anterior dorsals, and so on.   And they are hyperarctomets, quite unlike Alvarezsaurus. I agree with Mickey that an Alvarezsaurus-like form evolved into mononykiforms, but that a whole bunch of major clades split off in between them, during which time much evolution occurred (i.e., they're very polyphyletic).               I have already criticized the homoplastic characters (that supposedly unite 'Alvarezsauria' back when I was still on DML (see the DML archives when their 'search function' is working again). In particular, the procoelous caudal vertebrae (and sacrals) of mononykiformes are much more like those of Patagopterygiforms, than those of Alvarezsaurus. And the procoelous caudals of titanosaurs show that such a character can evolve independently in unrelated forms.               Alvarezsauria is DEAD, DEAD, DEAD, as far as I am concerned. I pronounced it dead quite some time ago, but now I am increasingly inclined to nail the coffin shut and bury it for good.   R.I.P.   I don't care if everyone from Larry Martin to Mary Norell thinks it's a clade!!! That it is extremely popular with both BANDits and BADD doesn't make it right. A Flat Earth was once a popular concept as well.               What we need to do now is look for the real Alvarezsaurus relatives among the dromies or related basal 'birds'.   That is why I have preliminarily assigned Alvarezsaurus to Order Archaeopterygiformes. If it doesn't belong there, I might have to put it back outside of AVES with the therizinosaurs (present sister group of my AVES). We shall see.

Ken, A. calvoi is unknown for sterna, so unless you are endowed with the ability to communicate with the dead bodies of maniraptorans, it could have well had a keeled sterna. The slight variation between the levels of the anterior and greater trochanters only indicate that the derived version developed independently within the Alvarezsauria. As noted by Cazola, you only questioned the validity of four characters leaving nine others unchallenged. The mononykines would be developing their hyperarctometarsus (which does not appear to be difficult to do, just fusing more of the distal metatarsus, that is) independently with avimimids also considering where you are placing them. Also, A. shares features with derived birds that are not seen in mononykines.

I find it curious that you find it more parsimonious to ally the mononykines deep within Aves and consider the synapomorphies of Pygostylia, Ornithothoraces, and Ornithuromorpha to have been reversed in those mononykines. Ken, seriously, consider this. You are advocating-

Mononykines re-developed a 35+ caudal series from 24 or less caudals. Mononykines re-developed an entirely mobile tail. Mononykines re-developed an enlarged maxillary body. Mononykines re-developed nearly flat, fused scapulocoracoid articulations. Mononykines re-developed simple sterna without the numerous processes. Mononykines re-developed elongate caudal postacetabular blades. Mononykines re-converted many of their dorsosacrals back into dorsals. Mononykines re-enlarged their first manual claws extremely. Mononykines re-developed enlarged external mandibular fenestra.

And many more reversals and parallelisms would be implied by such a derived placement but I cannot explain them all for lack of time.

I presume that your critique is such:
http://www.cmnh.org/dinoarch/2002Feb/msg00324.html

I encourage you to re-read the responses made by HPs Marjanovic, Cazola, Mortimer, & Longrich.

The presence of procoelous caudals in titanosaurs is inrevelant in regards to their presence in alvarezsaurians. Among theropods, only Patagopteryx has them which indicates that they are still an excellent synapomorphy of Alvarezsauria.

And curiously, it was a concept that came about from non-scientists after many scientists and writers had written of a spherical earth.

Actually, you need to demonstrate that the nine other characters are invalid and you need to fully demonstrate that the four you first declared invalid truly are so.

Happy to respond to your next post,

Nick, Mononykines redeveloped enlarged external mandibular fenestrae??? Maybe you are thinking of confuciusornithids and oviraptorosaurs (they have the enlarged EMFs). And Mononykiform sterna are hardly simple. Do you think processes are more 'complex' than a deeply keeled sternum? A deep keel is one hell of a 'process' (while simple processes are a dime a dozen). And what groups have the pubis and ischium subparallel to one

I'm fully aware of which taxa have large EMFs. These are not to the extremes seen in confuciusornithids and oviraptorosaurs but are still larger and present unlike that of most pygostylians. The surangular is more posteriorly placed and the dentary has longer posterior ventral processes embracing the EMF. These are totally unlike pygostylians. BTW, the shape of the EMF in confuciusornithids and oviraptorosaurs is very dissimilar.

A deep keel? Good grief Ken, have you ever actually seen mononykine sterna? Or compared them to pygostylians? These processes are far more advanced than the keels of mononykines. And you can't demonstrate the absence of the keel in Alvarezsaurus, because A. lacks revelant material!

And ornithischians. It's still a relatively easy process to develop and we don't have the ischia or pubes of A. to compare!

You failed to notice that the flexion zones of alvarezsaurids and ornithurines are different or that A. lacks a skull so you can't say it didn't have prokinesis.

Could have well developed in parallel considering the other characters.

And some troodontids have 7 sacrals as well...

Well, first, I'm not a 'doubting Thomas', I'm a 'doubting Nick'. And regarding your new hypothesis, well, I'd help you look for more support if you could actually demonstrate that all, note all, the shared characters of mononykines and Alvarezsaurus are absolute garbage, you haven't really disproved them conclusively either now that I think about it...

And maybe it is time for the loner to catch up and figure out this idea isn't working...

This is your pet theory, I don't see why you can't work on it. Afterall, I don't see you trying to demonstrate that Monolophosaurus jiangi is a spinosaurian or that GS Paul was wrong in including 'ornitholestines', allosaurs and tyrannosaurids in the same clade (true it's been done but it's interesting to search for support for such a concept only to prove it false!)... I'm a little too busy right now to mess with this. I honestly have not observed you attempting to falsify your ideas which is an important thing to do no matter what. And it's nice you admit that you don't have all the answers...

all I care to say on the matter til later, it's far too late as is, and I'll start rhyming soon so I should catch some sleep.

Ken Kinman wrote-

True.

Not Patagonykus. This would only help place them next to pygostylians anyway.

You must define these.

Patagonykus has separate anterior and greater trochanters, like dromaeosaurids. Only mononykines have them fused completely. And again, this was present more basally on the bird line than at Ornithurae.

Complex distribution. In Rahonavis, pygostylians, derived troodontids and most dromaeosaurs. But not in Archaeopteryx, Sinovenator or Microraptor. It certainly doesn't help Mononykus be anywhere closer to birds than Confuciusornis.

Patagonykus isn't. Neither are any birds of course....

Also, Sereno showed the prokinesis to be differently developed in Shuvuuia and neornithines. Mononykines only have five sacrals (Norell et al., 2001). Patagonykus lacks the medial cnemial crest of Mononykus. The pubis and ischium are parallel in most opisthopubic taxa, but probably not the mesopubic Patagonykus. So, you have the elongate sternum, which is fully keeled. I suppose two characters are better than none.

Mickey Mortimer

Mickey and Nick, I now agree with you (partially). I jumped Mononykiformes (and Avimimiformes) down too many nodes this week. I swung the pendulum too far the other way, and thus was not practicing what I preach. Shame on me. However, this does not alter my belief that 'Alvarezsauria' is polyphyletic. There are still plenty of clades branching off between Alvarezsaurus and the mononykiforms (just not as many as I had hoped). By the way, is it correct that Avimimus definitely had gastralia, but that gastralia are not known from mononykiforms or therizinosaurs? I'm trying to figure out how many times gastralia were lost in maniraptors.

Ken Kinman wrote-

Segnosaurus preserves gastralia (Barsbold and Perle, 1980). It's unknown in Avimimus and alvarezsaurids. No really good articulated skeletons are known. Even Scansoriopteryx only preserves a few, and is fairly complete. Birds as advanced as Yixianornis (an ornithuromorph, or perhaps ornithurine) had gastralia too.

Norell et al. (2001) code them as having five sacrals, which I'll trust until the Mesozoic Birds book gets published, with Novas and Pol's new alvarezsaurid description. But if someone can find a good reference showing they had seven....

Mickey Mortimer

Well, it's good you recognize this Ken.

I may agree in part! Except I think that the only clades branching off are those wacky basal alvarezsaurs... which reminds me, why do you accept the alvarezsaurid/mononykiform relationship of Rapator ornitholestoides? I don't object to it and have often supported it, I'm just curious why you so readily accept it but not the relationship of alvarezsaurs/mononykiforms.

I was under the impression that gastralia were lost only a few times within Aves, but I may be wrong. I have a similar but not question, ie. did predentatans have gastralia?

I wonder why you can't seem to get the search engine to work, I've been using it for some time, particularly today at school.

Nick, I still can't get the DML archives search to work. I wonder if others are having this problem? As far as I know predentatans (ornithischians) did not have gastralia. Not sure why though