*Henosferus* and mammal...imorph phylogeny

[David Marjanovic <david.marjanovic@gmx.at>]

-------- Original-Nachricht --------
Datum: Tue, 05 Jun 2007 09:37:01 -0600 (MDT)
Von: "Richard W. Travsky" <rtravsky@uwyo.edu>
Betreff: Introducing Asfaltomylos's sister

> http://digitallibrary.amnh.org/dspace/bitstream/2246/5857/1/N3566.pdf

Thanks for the link, I just finished reading the paper. The authors try both 
ordering some characters and keeping all unordered. The ordered analysis finds 
three MPTs; their strict consensus "collapse[s] the eutherians into an 
unresolved tetrachotomy and also collapse[s] *Kielantherium* and *Aegialodon* 
in a position basal to Theria. The unordered analysis resulted in a single most 
parsimonious tree [...] that resolved the eutherian clade, the relationships of 
*Kielantherium* and *Aegialodon* (grouping them in a monophyletic sister-group 
to therians), and, most surprisingly, moved *Haramiyavia* from a sister-group 
relationship to tritylodontids [...] to a position basal to Multituberculata".

Sometimes, then, having more MPTs is better.

That said, including more eutherians would probably have helped -- there are 
only four in the analysis: *Montanalestes* (AFAIK an isolated tooth), 
*Asioryctes*, *Erinaceus* (the extant hedgehog), and *Prokennalestes*.

The content of the mammalian crown-group is much smaller in this analysis than 
elsewhere:

--+--*Sinoconodon*
  `--+--+--*Megazostrodon*
     |  `--+--*Morganucodon*
     |     `--*Dinnetherium*
     `--+--*Haldanodon* (*Castorocauda* is not in the matrix)
        `--+--*Hadrocodium*
           `--+--*Priacodon* + *Trioracodon*
              `--+--*Jeholodens*
                 `--+--*Gobiconodon* + *Amphilestes*
                    `--+--*Kuehneotherium*
                       `--+--*Tinodon*
                          `--+--Zhangheotheriidae
                             `--+--*Shuotherium*
                                `--+--Multituberculata
                                   `--crown-group

Within the crown-group, *Deltatheridium* is outside of (*Pappotherium* + 
Theria). That may be because *Eomaia* and *Sinodelphys* are missing. If *D.* 
moves, the trichotomy the (*D.* + (*P.* + Theria)) clade forms with 
*Aegialodon* and *Kielantherium* might be resolved.

*Fruitafossor* is missing, too...

Then the authors argue for a reinterpretation of the tooth cusp homologies of 
Australosphenida, modify the matrix accordingly, and run it again, with the 
same characters ordered as before. The multituberculates jump into the 
crown-group -- "inside Australosphenida as the sister-group of Monotremata, a 
result also obtained during the standard runs under certain conditions." :-o 
OK, that's it. I retract all claims of certainty about basal mammal phylogeny.

Running the modified matrix with all characters unordered produces 33 MPTs and 
a poorly resolved majority-rule consensus. "This area of the tree [around the 
base of the crown-group and within Australosphenida] is obviously very labile 
and susceptible to drastic topological collapses, probably due to the lack of 
cranial, postcranial, and upper dental information for most of the 
australosphenidans."

-----------------

While I am at it, the name *Henosferus molus* has a few problems.

Firstly, a "holotype" is designated for the genus instead of a "type species". 
The intent is obvious and unambiguous, so I don't think anyone will bother, but 
the letter of the Code is violated. -- This may be connected to the fact that 
the paper is chock full of typos (mostly trivial, but including "*Henosfenos*").

Secondly, henos is explained as Greek "old", and ferus as Latin "animal" -- but 
it means "wild", not "animal"! We have thus an uneasy concatenation of two 
adjectives.

Most importantly, molus is explained as "From the Latin _mola_, meaning 
millstone [...]". But there are no transgender millstones. _mola_ is a noun in 
apposition, not an adjective, so the correct name is *Henosferus mola* -- 
unless a literalist insists that no type species has been designated, that is.
-- 
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