ORNITOLOGIA NEOTROPICAL 15 (Suppl.): 293–299, 2004
© The Neotropical Ornithological Society

TINAMOU (TINAMIDAE) SYSTEMATICS: A PRELIMINARYCOMBINED ANALYSIS OF MORPHOLOGY AND MOLECULES
Sara Bertelli1 & Ana Luz Porzecanski2
1

Department of Ornithology, American Museum of Natural History, Central Park West at 79thStreet, New York, New York 10024-5192, USA. E-mail: bertelli@amnh.org

2Center for Biodiversity and Conservation, American Museum of Natural History, Central ParkWest at 79th Street, New York, New York 10024-5192, USA.

Resumen. – Sistemática de tinámidos (Tinamidae): un análisis combinado preliminar de morfología
y moléculas. – El interés en la evolución de las perdices (Palaeognathiformes: Tinamidae) deriva de queson consideradas primitivas entre las aves actuales. Pese a esto, el conocimiento acerca de la filogenia deeste grupo Neotropical es muy escaso. Dos nuevos estudios produjeron filogenias de la familia usando
morfología externa e interna (237 caracteres) y secuencias de ADN mitocondrial (1143 pb) y nuclear (1145pb), respectivamente. Las dos hipótesis presentan algunas similitudes pero también varias incongruencias:
ambas apoyan la monofilia del grupo de las perdices de áreas abiertas pero son incongruentes en lamonofilia de las perdices de selva y las relaciones filogenéticas dentro de estos dos grupos. Aquí presentamos un resumen de los dos estudios anteriores y los datos moleculares y morfológicos en un análisis combinado. El análisis bajo pesos implicados divide la familia en dos grupos monofiléticos, uno compuesto
por las especies de selva y el otro por las especies de áreas abiertas. Estos resultados son también una de lasdos hipótesis alternativas obtenidas en los análisis con pesos iguales. Además, Eudromia y Tinamotis ocupan
una posición basal dentro de las perdices de áreas abiertas, y todos los géneros tradicionales son redelimitados como monofiléticos.
Abstract. – Interest in the evolution of the tinamous (Palaeonathiformes: Tinamidae) derives from thefact that they are primitive among extant birds. In spite of this, very little is known about the phylogeny ofthis Neotropical group. Two new studies produced phylogenies for the family using external and internal
morphology (237 characters) and mitochondrial (1143 bp) and nuclear (1145 bp) DNA sequences, respectively. The two hypotheses had some similarities but also several disagreements: both recovered a clade ofaridland tinamous but they disagreed on the monophyly of the forest-dwelling tinamous, as well as on therelationships within these two groups. Here we summarize the previous two studies and combine the morphological and molecular dataset into a single analysis. In the weighted combined hypothesis, the family is
divided into two monophyletic groups, one composed of forest taxa, and one of aridland taxa. This is also
one of the two alternative hypotheses recovered in unweighted analyses. The combined tree also places
Eudromia and Tinamotis as basal within the aridland tinamous, and recovers all traditional genera as monophyletic. Accepted 29 December 2003.
Key words: Tinamidae, tinamous, systematics, molecular, morphology, combined analysis.

INTRODUCTION
Ratites and tinamous (Infraclass Palaeognathae) together are the sister group to allother living birds (Cracraft & Clarke 2001,

Groth & Barrowclough 1999). The family
Tinamidae comprises 47 described species
that have been traditionally classified intonine genera (Blake 1977, Sibley & Monroe1990), but remarkably few systematic studies
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FIG. 1. A) Intergeneric relationships obtained in a previous cladistic analysis of morphological data (modified from Bertelli 2002). B) Intergeneric relationships obtained in previous maximum parsimony and maximum likelihood analyses of morphological data (modified from Porzecanski 2003).

have evaluated their generic monophyly andinterrelationships. Building on the work ofSalvadori (1895) and von Boetticher (1934),
Miranda- Ribeiro (1938) divided the tinamou
species into two general categories, and proposed a subfamily for each of these: one harboring the forest tinamous, Tinaminae, andthe other composed of open-area or aridland
tinamous, Nothurinae. Subsequent studies
focused on subsets of the genera and particular aspects of the morphology (Jehl 1971,Hudson et al. 1972, Elzanowski 1982), but it294

was not until very recently that comprehensive and modern phylogenetic analyses of thefamily were performed.
Bertelli (2002) and Bertelli et al. (2002)
presented cladistic analyses of the family
based on morphological data (see also Bertelli2004). The most comprehensive databaseincluded characters of several types: osteological (108 characters), integumentary (80),myological (40), and behavioral/reproductive(11) (Bertelli 2002). The resulting morphological hypothesis does not recover a monophyl-

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etic assemblage of forest tinamous (Fig. 1A).
The forest genera are placed at the base of thetree and are related sequentially to a morederived, and monophyletic, assemblage ofaridland tinamous. All genera are recovered as
monophyletic except Nothura. Finally, Eudromia and Tinamotis are sister groups, and form
the most derived clade within the aridland
tinamous (Fig. 1A).
Simultaneously, Porzecanski (2003) carriedout a molecular study of the family, using
mitochondrial cytochrome b and nuclear
RAG-2 gene sequences. The mitochondrialand nuclear trees conflicted with respect tothe basal relationships within the family, butbasal nodes lacked significant support in bothcases. The trees most congruent with othersources of data, such as plumage characters,
resulted from analyses of the nuclear
sequences alone, as well as of both loci
together. Unlike the morphological analyses,
those hypotheses divided the family into two
main clades corresponding to the aridland andforest tinamous (Fig. 1B). In addition, allmolecular trees recovered Nothura as a monophyletic genus, but Nothoprocta as paraphyletic.
Finally, Eudromia and Tinamotis formed aclade, but this clade was placed in a basal position within the aridland tinamous.
Given the multiple areas of conflictamong the morphological and moleculartinamou phylogenies, it was our aim toexplore the results of a combined, total-evidence analysis.

METHODS
We combined all of the existing morphological and molecular data into a single matrix.
This matrix was composed of 58 terminal taxa
and 2525 characters. Taxa included all
described species of Tinamidae (with subspecies in some cases) and what appears to be a
new form of Nothura (Bertelli et al. in prep.).
In addition, six ratite genera were used as out-groups, and a basal neognath, Megapodius, as
the root of the tree. When a particular type ofcharacter was not available for a given species
those characters were coded as missing. Allgenera, however, had a least one species forwhich all types of characters were available.
The matrix was analyzed using the program
SPA (Goloboff 1996) given that it allows theuse of cost matrices for complex morphological character state transformations (generalized Sankoff parsimony). For comparative
purposes, we carried out an equal weight analysis using NONA (Goloboff 1993a), and ananalysis under implied weights was carried out
using Pee-wee (Goloboff 1993b). In all cases,
searches were performed using 20 random
addition sequences with 20 TBR-rachet iterations each, for a total of 400 iterations. Branch
support was estimated by calculating absoluteand relative Bremer indices using the program
TNT (Goloboff et al. 2000).

RESULTSNONA and SPA results were incompatible
only with respect to three nodes, all internal
nodes with the genus Nothoprocta; the NONA
tree is shown here with the conflicting nodes
marked by asterisks (Fig. 2). This combined
hypothesis agrees with the molecular tree andthe morphological tree that aridland tinamous
form a monophyletic group. The relationships
among the forest tinamous, however, are notresolved: the genus Nothocercus is placed asbasal to all other tinamous in some optimaltrees, but the forest tinamous are monophyletic in other optimal trees.
The combined tree also agrees with themolecular hypothesis in placing Eudromia andTinamotis as basal within the aridland
tinamous. In contrast, and in agreement withthe morphological results, the combined tree
recovers Nothura as paraphyletic and Nothoprocta as monophyletic. Of the internal nodes
in the tree, 74% are relatively well-supported295

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FIG. 2. Strict consensus tree of the 44 most parsimonious trees obtained under equal weights analysis,
length = 979 steps, CI = 0.29. Values above and below branches show the absolute and relative Bremer
support values (see Methods). The branches that are not congruent with the consensus obtained underSankoff parsimony analysis are marked with a “x”.

(absolute Bremer support ≥ 3), and 42% ofthe nodes have relative Bremer support≥ 100. Except for Nothura, which is paraphyletic, and for Tinamus, the monophyly of allremaining polytypic genera is well-supported.
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When homoplastic characters are downweighted (i.e., in the Pee-Wee analysis), thefamily is divided into two groups: a forest
clade and an aridland clade (Fig. 3). In theseweighted analyses a new arrangement within

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FIG. 3. Single most optimal tree obtained under implied weight analysis. Support indicated as in Figure 2.

the aridland tinamous is recovered (see Fig. 3).
In this case, Rhynchotus is the sister group to aclade composed of Taoniscus, Nothura, andNothoprocta.

DISCUSSION
The low level of conflict found among theanalyses with and without step-matrices is anindication that the interaction among thecharacters is maintained regardless of whether
some of the character-state transformations
are penalized or not. These unweighted analyses result in two alternative hypotheses thatconflict with respect to the basal relationships
in the family. The weighted analysis resolves
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this conflict in favor of the least homoplastic
characters, which support one of the twoalternatives: a division of the family into a forest clade and an aridland clade. These preliminary results lend support to Miranda-Ribeiro’s(1938) division of the family into two subfamilies and would suggest an early divergence
between forest and aridland taxa, followed bylittle plasticity in broad habitat preferences
over the rest of the group’s evolution. In addition, all of the traditional genera are recovered
as monophyletic in the weighted hypothesis.
Cytochrome b data are considered to besaturated at the distances found among
tinamous (Porzecanski 2003). Nevertheless,we find that they provide a similar number ofsynapomorphies in the basal nodes as themorphology. Thus, all types of characters arecontributing evidence at the different hierarchical levels of the tree. Nodal support varies
throughout the trees, with areas of conflictamong the different types of characters visible as areas of particularly low branch support. These areas of the tree will require
further study, preferably with expanded
molecular and morphological sampling.
The molecular data were previously used
(Porzecanski 2003) to shed light on the timingof diversification within the family. Given thatsome of the same nodes are recovered in thecombined weighted analysis, those estimates
apply here as well. Based on alternative calibrations of the nuclear distances, the earliest
divergences within Tinamidae are postulated
to have occurred in the early Eocene, whilemost of the subsequent diversification within
the family is estimated to have occurred
between the Oligocene and Miocene.

ACKOWLEDGMENTS
S. Bertelli thanks the Chapman Memorial
Fund at the American Museum of Natural
History for post-doctoral support. A. Porzecanski thanks J. Cracraft, the AMNH, and298

Columbia University for support during herdoctoral research.

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