Proposal
(321) to South American
Classification Committee
Remove Parkerthraustes
and Saltator from Cardinalidae
Effect on SACC: This would transfer two genera from Cardinalidae
to Incertae Sedis.
Background: SACC classification currently places Parkerthraustes in
the Cardinalidae, with the following footnote:
6. Parkerthraustes
humeralis was formerly (e.g., Hellmayr 1938, Pinto 1944, Meyer
de Schauensee 1970, Paynter 1970c, Ridgely & Tudor 1989, Sibley &
Monroe 1990) placed in the genus Caryothraustes; for rationale for
generic separation of Parkerthraustes from Caryothraustes, as
anticipated by Hellmayr (1938), see Demastes & Remsen (1994) and Remsen
(1997). Recent genetic data (Klicka et al. 2007) confirm that Parkerthraustes is
not part of Caryothraustes but also that it likely belongs in the
Thraupidae. Proposal badly needed.
Thus, this species, once considered congeneric with a true
cardinaline (sensu Klicka et al.) not only does not belong in that genus but
also in likely a separate family.
The genus Saltator, although itself widely suspected of
being polyphyletic, has always been placed with the cardinalines. I do not know
what the basis for that was.
New information: Klicka et al.'s (2007) analysis
included 102 genera of tanagers, emberizines, and cardinalines. The genetic
sampling consisted of 2281 bp of two mitochondrial genes, ND2 and cyt-b ... a
nice sample. Not only are Saltator and Parkerthraustes not in the
Cardinalidae but there is also support for placement within the Thraupidae. The
critical node (#2 in their Fig. 1) for that placement has strong support
(> 95% Bayesian). That node places Saltator plus Saltatricula as
sister to the rest of the tanagers. Saltator rufiventris is not a Saltator
but is deeply embedded within the Thraupidae (to be addressed in another
proposal). Parkerthraustes is also inside Thraupidae, but support for
the nodes, including a relationship to Chlorochrysa, is weak.
Analysis and Recommendation: mtDNA is widely
considered a reliable predictor of phylogeny at these levels of taxonomy, and
certainly these data sets represent the first truly scientific estimates of the
phylogeny and classification of this group. There is no support for retaining
these two genera in Cardinalidae, and I am unaware of whatever rationale was
used originally for the placement of Saltator there (and when you look,
as in our synoptic series, at the true cardinalines and Saltator, one
cannot see any phenotypic signal that suggests a relationship.
For me, the only question is whether to place them within
Thraupidae or leave them as Incertae Sedis. Given that their placement in
Thraupidae is based on one node and one study (and no nuclear DNA analyzed so
far), and given that Burns, Klicka et al. will undoubtedly be publishing more
on Thraupidae and Saltator, I suggest a cautious approach by placing
them temporarily as Incertae Sedis, including even S. rufiventris, with
all appropriate footnotes indicating their likely relationship to Thraupidae.
Thus, I recommend a YES vote on their deportation to Incertae Sedis. If someone
wants to submit a separate proposal for direct placement in Thraupidae, please
do so.
References:
KLICKA, J.,
K. BURNS, AND G. M. SPELLMAN. 2007. Defining a monophyletic Cardinalini: A
molecular perspective. Molecular Phylogenetics and Evolution 45: 1014-1032.
[See SACC Literature Cited for others]
Van Remsen
(in consultation with Kevin Burns and John Klicka), December 2007
______________________________________________________________________________________________________
Comments from Cadena: "YES to moving them out from
Cardinalidae, but NO for placing them incertae sedis. I think the data
are sufficient to place Parkerthraustes and Saltator in the
Thraupidae. Figure 1 in Klicka et al. shows a strongly supported clade that
includes the Thraupidae, Saltator, and Parkerthraustes. Unless
one wants to create a new family for Saltator, which doesn't appear
sensible, the only alternative that is consistent with our current
understanding of phylogeny is to treat all the members of the clade as
representatives of a single family, Thraupidae. It is important to note that
Klicka et al. 2007 state that "our data cannot rule out the hypothesis
that they [Saltator] are a sister clade to the Cardinalini", a
conclusion based on a non-significant SH test of topologies. This statistical
test is known to be conservative, and the other way to look at this is that
posterior probability support for a clade formed by Saltator and
the Cardinalini is less than 0.05, which means that using a Bayesian criterion,
one can reject that hypothesis of relationships. In sum, I think we have enough
data to support moving these taxa to the Thraupidae. I concur with Alvaro's
recent comment in that we tend to overuse the incertae sedis "rank",
and that we should go with the best available phylogenetic evidence."
Comments from Stiles: "YES on transferring these
two genera out of Cardinalidae (where I suspect that their massive bills had
been the main argument for placing them there). However, I agree with Daniel
that current evidence is sufficient for placing them in Thraupidae, probably at
the beginning of that family as they are evidently sister to the rest. The lack
of sexual dichromatism is also a feature shared with most "true"
tanagers but not with most (all?) cardinalines. Like Daniel, I see nothing
useful to be gained by either leaving the saltators in "incertae
sedis" or erecting a separate family for them."
Comments from Stotz: "YES. While tempted to move them all the way to
Thraupidae, it seems like there is some question as to the specific placement
within that family."
Comments from Zimmer: "YES for moving both genera
out of Cardinalidae, and into Thraupidae. I find Daniel and Gary's arguments
against temporary placement as incertae sedis compelling."
Comments from Robbins: "YES to both removing these
from Cardinalidae and placing them in Thraupidae."
Comments from Pacheco: "YES. Igualmente (a #320), a partir das informações
apresentadas, sou favorável a remoção destes dois gêneros de Cardinalidae e sua
inserção em Thraupidae."