[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Eoconfuciusornis, Paraprotopteryx, Pengornis, Aberratiodontus and other basal birds



Eike wrote-

> Cool! Many thanks! (You gonna update it to TTDB?)

Eventually.  First I have to get the website online again.

> Anything new on the Khulsan foot since
> http://www.biology.ualberta.ca/faculty//philip_currie/uploads/pdfs/2000/2000Mongolian_Theropod.pdf
> ?
>
> Due to it being so plesiomorphic and the hypodigm so
> small, it is resisting quantitative analysis at
> present.
> http://www.dinodata.org/index.php?option=com_content&task=view&id=6628&Itemid=67
> takes a qualitative look and puts a rather convincing
> limit on how much of an avian it could have been if it
> were avian. But there should be a bit more juvie
> non-avian paravian material around than in 2000.

Haha.  That DinoData summary was written by me.  The more recent summary that 
was on the Theropod Database (copied below) has not been affected by this new 
bird analysis.  Indeed, the fact it comes out by basal troodontids in this new 
analysis further supports such a relationship.

Relationships- The proximoventral heel on phalanx II-2 and hyperextendable 
second digit show Hulsanpes is non-ornithurine (sensu Gauthier) eumaniraptoran. 
When entered into Senter's (2007) matrix, Hulsanpes emerges as a troodontid 
based on the distally narrowing metatarsus. Hulsanpes resembles Sinovenator 
more than other troodontids in having a ginglymoid metatarsal II, but resembles 
most eumaniraptorans besides Sinovenator and some avialans in having a 
ginglymoid metatarsal III. It shares anteroposteriorly deep metatarsals with 
troodontids more derived than Sinovenator. It is more basal than Sinovenator, 
Mei and other troodontids in having a broader metatarsus, and it is more basal 
than Mei and other troodontids except Sinovenator in having metatarsals II and 
IV subequal in thickness. The basic morphology of the metatarsus is extremely 
similar to Sinovenator, including the short metatarsal II with reduced distal 
condyle and large somewhat divergent condyle of metatarsal IV.

Osmolska allied this species with dromaeosaurids based on the ginglymoid second 
and third metatarsals and subequally developed metatarsals II and IV, but noted 
it resembled troodontids in the narrow metatarsus and weakly developed second 
pedal digit. She dismissed avian origins based on the lack of fusion. Senter et 
al. (2004) is the only published analysis to include Hulsanpes, which emerged 
as a dromaeosaurid because they miscoded the ginglymoid metatarsal II as absent 
in Sinovenator. Chiappe and Norell (Norell pers. comm. to Currie, 2001) think 
Hulsanpes is not a dromaeosaurid, but from "another more speciose branch of the 
Maniraptora". Holtz (DML, 1995) wrote that the metatarsals and distal tarsals 
are fused at least distally in this species, like birds. He also cryptically 
said "future work may show why this is no surprise....". Then in May of 1997 
(DML), Holtz said that Hulsanpes is almost certainly not a dromaeosaurid. The 
description specifically states that the metatarsus is
 unfused however, contradicting Holtz's statement (but not his conclusion). 
However, the only obviously birdlike character is the proximally expanded 
metatarsal III also seen in Yandangornis and basal avebrevicaudans. Though not 
included in Senter's character list, placing Hulsanpes in Avialae results in 
trees at least three steps longer. Thus the expanded third metatarsal would not 
be enough to remove Hulsanpes from Troodontidae. An additional test was carried 
out by adding Hulsanpes to a matrix of published Mesozoic birds (using the 
characters of Clarke and Chiappe, along with many more taxa). Though the 
excavated plantar metatarsus surface is similar to some pygostylians, Hulsanpes 
still falls out by deinonychosaurs at the base of the tree.

>> | `--+--Velociraptor
>> | `--+--Deinonychus
>> | `--Wyleyia
>
> How well-supported? (Apparently it is possible to
> recognize a broken humerus as velociraptorine with
> enough certainty to leave no place for a
> question-mark. Intriguing indeed. How are the
> characters that put it here distributed among Aves -
> in other words: if its placement here is a result of
> LBA+conserved plesiomorphies, is there anywhere in
> Aves where it would most sensibly go?)

> The "question-mark" was misleading... shouold have
> said "asterisk".

As explained in the prior post, an asterisk means the taxon is incertae sedis 
within the clade.  So Piksi can come out in numerous places in Ornithothoraces 
with equal support, for instance.  Wyleyia didn't get an asterisk because it 
was always sister group to Deinonychus in the most parsimonious trees.  That 
says nothing about how robustly this is supported though.  Indeed, only one 
step is needed to move it into Avialae sensu Gauthier.  The only character 
placing it in Dromaeosauridae and sister to Deinonychus is the proximal humeral 
surface that is V-shaped in proximal view, which is also found in most 
enantiornithines.

Nick wrote-

> You should score alvarezsaurids and see how they alter the topology,if at 
> all. :-)

I was thinking of doing that too, though I'd want to expand the outgroup to 
include basal ornithomimosaurs if I did.  Of course, the more expanded the 
outgroup gets, the less likely that characters included for a bird analysis are 
going to be able to place them "correctly".

Mickey Mortimer