A monographic catalogue on the systematics and phylogeny of the South American iguanian lizard family Liolaemidae (Squamata, Iguania)
Author
Pincheira-Donoso, Daniel
Author
Scolaro, J. Alejandro
Author
Sura, Piotr
text
Zootaxa
2008
2008-06-16
1800
1
85
journal article
86426
10.5281/zenodo.6789337
4885f120-14b4-425c-acc8-f2ba6960161c
11755334
6789337
Liolaemus
genus
In the recent decades,
Laurent (1983
,
1985b
,
1992
) was the first author that formulated an explicit and powerful hypothesis on the phylogenetic relationships of higher groups among
Liolaemus
lizards. After performing a series of statistical analyses on previously overlooked and underestimated morphological traits, he found that these lizards can be separated into two major groups, one mainly Andean-occidental and one Andean-oriental. Morphologically, the occidental group, called by
Laurent (1985b
,
1992
) “Chilean group”, includes species characterized by narrow supralabial scales, usually four or fewer, the last one elongated and upturned in its posterior margin, and with a low number of precloacal glands (= preanal pores), usually four or fewer (see
Etheridge 1995
). This group of taxa was placed by
Laurent (1985b
,
1992
) into the subgenus
Liolaemus
(
sensu stricto
). Species belonging to the oriental group, called “Argentinean group”, exhibit short supralabial scales, usually five or more, the last one is not upturned posteriorly, a high number of precloacal glands, usually five or more (up to 12), the puboischiotibialis muscle (flexor tibialis internus
fide
Abdala, V.
et al.
2006) hypertrophied, and a conspicuous sharp, blade-like process on the tibia (see
Etheridge 1995
; also
Núñez
et al.
2000
). This complex of species was recognized under the subgenus
Eulaemus
(
Laurent 1992
; see also
Etheridge 1995
). More recently, additional morphological evidence led
Etheridge (1995)
to support this classification model, who also recognized that a series of species grouped into the
Eulaemus
subgenus exhibit a unique patch of enlarged scales on the posterior surface of the thigh. These lizards were then recognized as the
boulengeri
complex (see
Cei 1993
;
Etheridge 1995
,
2000
;
Halloy
et al.
1998
;
Pincheira-Donoso & Núñez 2005
;
Abdala 2007
, for details). Remarkably, these groups of species have remained largely accepted, and more importantly, have recently been supported by phylogenetic hypotheses constructed on both morphological and molecular evidence (
e.g.
Etheridge 2000
;
Schulte
et al.
2000
;
Espinoza
et al.
2004
;
Cruz
et al.
2005
;
Abdala 2007
).
FIGURE 2.
Phylogenetic relationships between the major clades forming the family
Liolaemidae
. The phylogenetic structure of the tree is primarily based on
Schulte
et al.
(2000
,
2004
),
Espinoza
et al.
(2004)
and
Cruz
et al.
(2005)
. The line
magellanicus
is not shown in this figure (it is part of the
Donosolaemus-Vilcunia
clade), but see figure 4 for details on its phylogenetic position within the
Liolaemus
genus.
Even though
Laurent (1983
,
1985b
,
1992
) and
Etheridge (1995)
reported pioneer evidence to hypothesize relationships among higher-level groups within
Liolaemus
, the first explicit phylogenetic study focusing on the relationships among species within these clades was only recently published (
Schulte
et al.
2000
; see also
Schulte
et al.
1998
). Schulte
et al.
’s (2000) molecular phylogeny supported substantially the hypothesis of a major event of
Liolaemus
diversification into two main clades, the subgenus
Liolaemus
and the series
signifier
(indicated by Schulte
et al.
as subgenus
Eulaemus
). In addition, this phylogenetic study provided the first empirical evidence to test the hypothesis that austral
Liolaemus
species
recognized as members of the groups
archeforus
and
kingii
(
Scolaro & Cei 1997
)
may represent primitive Patagonian states in the evolutionary history of this genus (
Laurent 1985b
; see also
Cei 1986
). According to
Laurent (1985b)
, morphological peculiarities observed in these austral species would be indicative of their ancestral position within
Liolaemus
(see also
Etheridge 1995
). However, Schulte
et al.
’s (2000) results rejected such claims. Indeed, this phylogeny revealed that the
archeforus-kingii
line (i.e. subgenus
Donosolaemus
) would be related to the
Eulaemus
subgenus, and therefore, that it originated after the first main diversification event experienced by this genus, during the Tertiary (
e.g.
Pincheira-Donoso & Núñez 2003
). Later phylogenetic studies have provided, in general, similar results in relation to the relationships among subgenera, among clades within subgenera (
e.g.
groups
alticolor
,
elongatus-kriegi
,
boulengeri
), and among series of species (
e.g.
Avila
et al.
2004
;
Espinoza
et al.
2004
;
Morando
et al.
2004
;
Cruz
et al.
2005
;
Abdala 2007
;
Pincheira-Donoso
et al.
2007a
; see also
Lobo 2001
;
Díaz & Lobo 2006
, for morphological based phylogenies).
In spite of an increasing number of studies exploring relationships among
Liolaemus
taxa published over the last few years, many aspects of the phylogeny of this lineage remain still controversial. For example, the position in the phylogenetic structure of the genus
Liolaemus
of
L. pseudoanomalus
, a species recognized by Cei (
e.g.
1986, 1993; see also
Laurent 1984a
;
Núñez & Yáñez 1984b
) as a member of the
anomalus
group, tends to show substantial discordance among different studies (
e.g.
Schulte
et al.
2004
;
Espinoza
et al.
2004
;
Abdala 2007
;
Pincheira-Donoso
et al.
2007a
). More importantly, the phylogenetic relationships between a large number of
Liolaemus
species
remain to be studied for the first time.