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Eoconfuciusornis, Paraprotopteryx, Pengornis, Aberratiodontus and other basal birds



There have been several Mesozoic birds described recently, so I figured I'd add 
them to my prior bird matrix (http://dml.cmnh.org/2007Mar/msg00079.html) and 
see what's changed in a year.  Since that time, I've added numerous 
non-pygostylian outgroups to make the basal relations better tested than 
before, when it consisted of Dromaeosauridae, Archaeopteryx, Shenzhouraptor (= 
Jeholornis) and Sapeornis.  Now there's also Omnivoropteryx, Yuan's unpublished 
omnivoropterygid from his thesis, Dalianraptor, Yandangornis, Jixiangornis, 
Epidendrosaurus (= Scansoriopteryx), Hulsanpes, Deinonychus, Velociraptor, 
Bambiraptor, Sinornithosaurus, Microraptor (= Cryptovolans), Unenlagia, 
Rahonavis, Buitreraptor, Mahakala, Troodon, Sinornithoides, Sinusonasus, 
Byronosaurus, IGM 100/44, the largely undescribed basal Zos Canyon troodontid, 
Mei, Sinovenator, Jinfengopteryx, Pedopenna and with Protarchaeopterygidae 
(Incisivosaurus and Protarchaeopteryx) as the ultimate outgroup.  New ingroup 
taxa include
 Eoconfuciusornis, Pengornis, Paraprotopteryx, Martinavis, Potamornis, 
Asiahesperornis and Enaliornis.  Additionally, Protopteryx, Longipteryx, 
Archaeopteryx, Sapeornis and Shenzhouraptor have been updated with new codings.

The next paragraph is copied verbatim from my prior post...
I ran the analysis with all taxa except Dapingfangornis and those described by 
Hou (1997) - Jibeinia, "Cathayornis" caudatus, Longchengornis, 
Cuspirostrisornis, Largirostrornis. This is because Hou's descriptions of other 
taxa in that work (Confuciusornis, etc.) are inaccurate and the illustrations 
are of very low quality. For instance, Confuciusornis is described as having a 
septomaxilla, prefrontal, patella and a free distal tarsal, contra Chiappe et 
al. (1999). Because every taxon affects every other taxon's placement, I didn't 
want inaccurate codings for Hou's taxa to change character distribution and 
topology of the whole tree. Dapingfangornis has a similarly bad illustration, 
and the authors' interpretation of the skull at least seems to be flawed (see 
http://dml.cmnh.org/2006Apr/msg00170.html). 
Of course the large amount of missing data resulted in huge polytomies, but it 
was important to include even fragmentary taxa (as long as they had unique 
character combinations) in order to get a tree with the best character 
distribution and topology for all taxa. Fragmentary taxa were then excluded 
from the tree (but not the analysis) until a fully resolved tree was present. 
Each taxon was then reintroduced to the tree separately to determine the 
possible places it could go in the phylogeny.
The resulting cladogram is shown below. It uses the same format as my website, 
with an asterisk meaning the taxon is incertae sedis within the node it's 
placed at. Most clade names have been phylogenetically defined.

|--Protarchaeopterygidae
`--Paraves
   |*-Hulsanpes 
   |--Troodontidae
   |  |--Sinusonasus
   |  `--+--Sinornithoides
   |     `--Troodon
   |--Zos Canyon troodontid
   `--+--+--Mei
      |  `--+--Jinfengopteryx
      |     `--Sinovenator
      `--Eumaniraptora
         |--Dromaeosauridae
         |  |*--IGM 100/44
         |  |--Unenlagiinae
         |  |  |--Mahakala
         |  |  `--+--Rahonavis
         |  |     `--Unenlagia
         |  `--+--Microraptoria
         |     |  |--Bambiraptor
         |     |  `--+--Sinornithosaurus
         |     |     `--Microraptor
         |     `--+--Velociraptor
         |        `--+--Deinonychus
         |           `--Wyleyia
         `--Avialae sensu Gauthier
            |*-Pedopenna
            |--Byronosaurus
            |--Buitreraptor
            |--Epidendrosaurus
            `--Aves sensu Chiappe
               |--Archaeopteryx
               `--Ornithurae sensu Gauthier
                  |*-Catenoleimus
                  |--Shenzhouraptor
                  `--+--+--Dalianraptor
                     |  `--Jixiangornis
                     `--+--Yandangornis
                        `--Avebrevicauda
                           |--Omnivoropterygidae
                           |  |--unnamed omnivoropterygid
                           |  `--+--Omnivoropteryx
                           |     `--Sapeornis
                           `--Pygostylia
                              |--Confuciusornithidae
                              |  |--Eoconfuciusornis
                              |  |--"Proornis"
                              |  `--Confuciusornis
                              |--Changchengornis
                              `--Ornithothoraces
                                 |*-Piksi
                                 |--Enantiornithes
                                 |  |*-Abavornis
                                 |  |*-Explorornis? walkeri
                                 |  |*-Incolornis
                                 |  |*-Lebanon enantiornithine
                                 |  |*-Sazavis
                                 |  |--Explorornis nessovi
                                 |  |--Vorona
                                 |  |--Lectavis
                                 |  |--Elsornis
                                 |  `--+--Avisauridae
                                 |     |  |--Chaoyangia
                                 |     |  |--Avisaurus
                                 |     |  |--Soroavisaurus
                                 |     |  |--Nanantius
                                 |     |  `--Gobipteryx
                                 |     `--+--"Gobipipus"
                                 |        `--+--Pengornis
                                 |           `--+--Protopteryx
                                 |              `--+--Noguerornis
                                 |                 `--+*-Kizylkumavis
                                 |                    |--Longirostravis
                                 |                    `--+--Longipteryx
                                 |                       `--+--Eocathayornis
                                 |                          `--+*-Alexornis
                                 |                             |*-Gurilynia
                                 |                             |*-Martinavis
                                 |                             |--Enantiornis
                                 |                             
|--Paraprotopteryx
                                 |                             `--+*-Liaoxiornis
                                 |                                
|--Yungavolucris
                                 |                                |--Jibeinia
                                 |                                |--Hebeiornis
                                 |                                |--GMV 2158
                                 |                                |--GMV 2159
                                 |                                |--Spanish 
nestling
                                 |                                
|--+--Boluochia
                                 |                                |  |--IVPP 
V14238
                                 |                                |  
`--Dalingheornis
                                 |                                
|--Eoenantiornis
                                 |                                `--+--Sinornis
                                 |                                   
`--+*-Halimornis
                                 |                                      
|*-Otogornis
                                 |                                      
|--Aberratiodontus
                                 |                                      
|--Iberomesornis
                                 |                                      
|--+--Concornis
                                 |                                      |  
`--Neuquenornis
                                 |                                      
`--+--Eoalulavis
                                 |                                         
`--Liaoningornis
                                 `--Euornithes
                                    |--Hongshanornis
                                    `--+--Archaeorhynchus
                                       `--+--Yanornithidae
                                          |  |--Yanornis
                                          |  `--+--Yixianornis
                                          |     `--Songlingornis
                                          `--Ornithuromorpha
                                             |--Patagopteryx
                                             `--+--+--Ambiortus
                                                |  `--Apsaravis
                                                `--+--Enaliornis
                                                   `--Ornithurae sensu Chiappe
                                                      |--Hesperornithes
                                                      |  |--Baptornis
                                                      |  `--+--Asiahesperornis
                                                      |     `--Hesperornis
                                                      `--+--Gansus
                                                         `--Carinatae
                                                            |--Ichthyornis
                                                            `--+*-Apatornis
                                                               |--Limenavis
                                                               `--+--Iaceornis
                                                                  `--Neornithes
                                                                     
|--Palaeognathae
                                                                     |  
|--Lithornis
                                                                     |  
`--Crypturellus
                                                                     
`--Neognathae/Galloanserae
                                                                        
|--Anseriformes
                                                                        |  
|--Chauna
                                                                        |  
`--Anas
                                                                        
`--Galliformes
                                                                           
|--Crax
                                                                           
`--Gallus

It's interesting to note that Rahonavis clades with Unenlagia within 
dromaeosaurids instead of birds.  This is particularily relevent because the 
two studies that make up the bulk of this analysis (Chiappe's and Clarke's) 
found Rahonavis to be a bird, and because no deinonychosaurian, dromaeosaurid 
or unenlagiine characters were purposefully included (since Dromaeosauridae was 
a single OTU in both studies).  The absence of deinonychosaurian and troodontid 
characters means the polyphyly of Troodontidae and the position of Buitreraptor 
(often the most basal dromaeosaurid in my studies) are unimportant.  Wyleyia 
being a dromaeosaurid is an intriguing result.

Eoconfuciusornis was just described last month.  Zhang et al. claim it to be a 
stem-confuciusornithid (outside the Confuciusornis + Changchengornis clade).  
Of their supporting characters, the lack of deep lateral dorsal central fossae 
is equally likely to be an apomorphy as ornithothoracines primitively have 
them; the acromion seems no shorter than Confuciusornis; the short coracoid is 
an apomorphy (if not caused by breakage) since those of Shenzhouraptor, 
Jixiangornis and omnivoropterygids are long; the coracoid foramen isn't known 
to be absent in Changchengornis; the pubic foot of Changchengornis isn't known 
to be absent; the unfused astragalar ascending process is apomorphic if not 
ontogenetic, as omnivoropterygids and Yandangornis have fused ones.  The only 
seemingly valid character is the lower deltopectoral crest.  In my analysis, it 
comes out closer to Confuciusornis than to Changchengornis, the latter which 
may not even be a confuciusornithid.  This is based on manual
 phalanx II-2 being longer than II-1 (a primitive character, but a reversal 
since Jixiangornis, Dalianraptor, Yandangornis and omnivoropterygids have short 
II-2 phalanges), as well as the non-included characters enlarged surangular 
foramen, furcular arm with>20% of arm length, and manual phalanx II-2 bowed.  A 
large number of characters suggest the holotype is a juvenile (smaller size 
than any specimen examined by Chiappe et al. 1999, course ends of long bones, 
poorly fused premaxillae, unfused dentaries, unfused cervical ribs, unfused 
sacrum, apparently unossified uncinate processes and sternal ribs, largely 
unossified sternum, unfused carpometacarpus, tarsus not fused to tibia, and 
poorly fused metatarsus.  The lack of deep dorsal central fossae, low 
deltopectoral crest and absence of sternal processes may be due to ontogeny as 
well.  Zhang et al. argue it's an adult based on its supposedly medium size and 
elongate retrices.  Yet the humerus is ~39 mm judging by the figure and
 Chiappe et al. (1999) stated GMV -2131 with a humeral !
length of
ined.  Similarly, juvenile enantiornithines like GMV-2159, Jibeinia and 
Protopteryx have elongate retrices.  I would argue it's a juvenile 
Confuciusornis if not for the coracoid foramen, apparently well developed 
dorsal ulnar condyle, and pubic foot.

Paraprotopteryx was described last year by Zheng et al. and said to be most 
closely related to Protopteryx based on the elongate retrices, unfused 
carpometacarpus and tibiotarsus, and the presence of two phalanges on manual 
digit III.  Yet these are all primitive characters, and the lack of fusion is 
probably ontogenetic for both.  My analysis finds Paraprotopteryx to be more 
closely related to Enantiornis, Sinornis, etc. than to Protopteryx.  This is 
based on the convex lateral coracoid margin, posteromedial sternal process, 
narrow sternal xiphoid process, well developed olecranal fossa, short manual 
digit I, medially convex metacarpal I, distally restricted intermetacarpal 
space, and short manual phalanx II-2.

Pengornis was described earlier this year by Zhou et al..  They found it to be 
a basal enantiornithine slightly more derived than Protopteryx, using Clarke's 
bird matrix.  The character support is not listed, but the cladogram shows that 
the node separating Pengornis and Protopteryx only requires two steps to make 
it into a polytomy.  So whatever characters support this position are few in 
number, and were included in my study anyway since my character list comes 
largely from Clarke's.  I found it in a similar position, but slightly less 
derived than Protopteryx, based on the non-concave posteroproximal 
deltopectoral crest.  Neither position seems especially well supported, and 
it's fair to say both our studies agree Pengornis is very close to Protopteryx.

Aberratiodontus was mentioned in the Penguornis paper as not being an 
enantiornithine (which may be true, as it takes very few more steps to be a 
euornithine in my analysis) and possibly being a junior synonym of Yanornis.  
Yet they differ in my matrix in that Yanornis has no anterior premaxillary 
teeth, a sternal keel extending anteriorly, a broad sternal xiphoid process, an 
expansion on the lateral sternal process, paired posterior sternal foramina, no 
lateral coracoid process, a distal humeral margin perpendicular to the long 
axis of the shaft, a broad expanded manual phalanx II-1, a pubic foot, and 
distal metatarsal fusion.  Of these characters, only the humeral distal margin 
can be confirmed in photographs, as the other areas are indistinct or possibly 
incomplete (phalanx II-1).  However, their proportions differ by quite a bit.  
Compared to femoral length (which is only 3 mm longer in Aberratiodontus, 
excluding ontogenetic reasons for differing proportions), Yanornis has a
 skull 18% longer, a scapula 10% longer, a pubis 51% longer, a tibia 29% longer 
and a tarsometatarsus 13% longer.

Martinavis was based on several humeri, some part of the original El Brete 
enantiornithine material.  Walker et al. (2007) refer it to Euenantiornithes, 
which is a defunct taxon in my tree, since Iberomesornis groups with derived 
enantiornithine taxa.  Being based solely on humeri, placing Martinavis more 
securely within the derived enantiornithine clade doesn't seem possible at the 
moment.

Mickey Mortimer