Liolaemus lineomaculatus

Breitman, María Florencia, Morando, Mariana & Avila, Luciano Javier, 2013, Past and present taxonomy of the Liolaemus lineomaculatus section (Liolaemidae): is the morphological arrangement hypothesis valid?, Zoological Journal of the Linnean Society 168 (3), pp. 612-668 : 635-636

LIOLAEMUS LINEOMACULATUS SECTION: PRESENT

The L. lineomaculatus section is composed of 21 species distributed over a large area in Patagonia. In this paper, we have presented several classes of statistical analyses of morphological data and our results are concordant with the molecular evidence in recognizing three groups within the L. lineomaculatus section: the L. lineomaculatus , L. magellanicus , and L. kingii groups. The L. kingii group (referred to as the L. kingii-archeforus group in the Material and methods and Results sections of this paper) includes all the species that were previously recognized as two separate morphological groups ( L. kingii and L. archeforus ); as all the characters that had been previously considered diagnostic under the ‘morphological arrangement hypothesis’ for each group failed to clearly distinguish between them, we discourage the recognition of the L. kingii and L. archeforus groups as two differentiated entities and we consider all their 11 species to be included in one group called the L. kingii group (because this was the first described species from the group). Morphological characters do support differentiation of the L. magellanicus group, recently proposed on the basis of molecular data ( Breitman et al., 2011a).

Molecular data suggested that the divergence between the L. lineomaculatus section and its sister clade ( L. montanus section) occurred at the Middle Miocene (14.36 Mya; 95% HPD = 10.25– 18.64), the L. lineomaculatus group differentiated from the ( L. magellanicus , L. kingii ) clade around the Late Miocene (8.46 Mya; 95% HPD = 6.26–10.84), and the L. kingii group diverged from the L. magellanicus group around the Late Miocene/Early Pliocene (5.87 Mya; 95% HPD = 4.26–7.62) ( Breitman et al., 2011a).

The L. lineomaculatus group

The L. lineomaculatus group includes six species: L. avilae , L. hatcheri , L. kolengh , L. lineomaculatus , L. morandae , and L. silvanae . The distribution of these species extends from central Neuquén ( Christie, 2002) to south of Santa Cruz province, with some species widespread and others geographically restricted. The group and the morphological characters that define it were established by Etheridge (1995): absence of precloacal pores and presence of dorsal tridentate (or trifid) scales. Molecular support for this group is based on mitochondrial ( Espinoza et al., 2004; Schulte & Moreno-Roark, 2010) and nuclear genes, both analysed using standard concatenation as well as a species tree approach ( Breitman et al., 2011a).

This group differs from the L. magellanicus and the L. kingii groups in the absence of precloacal pores and the presence of trifid scales (individuals of L. avilae , L. morandae , and L. lineomaculatus present a lower percentage of trifid scales relative to L. hatcheri , L. kolengh , and L. silvanae ), a characteristic that was previously described in the literature ( Etheridge, 1995). Additionally, the number of ventral scales (61– 94 L. lineomaculatus, 49– 72 L. magellanicus, 78– 113 L. kingii) and midbody scales (43– 65 L. lineomaculatus, 36– 46 L. magellanicus, 55– 93 L. kingii) is intermediate for the L. lineomaculatus group compared with the L. magellanicus and L. kingii groups (with some degree of overlap). The L. lineomaculatus group also has an intermediate body size in agreement with the meristic variables. A disparate coloration pattern relative to the L. kingii group was also observed. Whereas species of the L. lineomaculatus group are characterized by two paravertebral and quadrangular black or brown series of blotches surrounded by two well-defined whitish lines (in general, to the tip of the tail), species of the L. kingii group do not show this pattern and present transversal lines or a wide vertebral line (Fig. 1). Sexual dimorphism is not evident in the meristic characters, but it is in the morphometric characters within the species included in the L. lineomaculatus group, with males having bigger heads and females having longer bodies.

The L. magellanicus group

The L. magellanicus group includes L. magellanicus and L. caparensis , which have the southernmost distributions of the L. lineomaculatus section; with L. caparensis only known from its type locality ( Breitman et al., 2011c), whereas L. magellanicus is widespread south of the Santa Cruz river and is the only species of Liolaemus inhabiting Tierra del Fuego Island ( Bottari, 1975).

The L. magellanicus group is a well-differentiated clade in both molecular and morphological characters. This two-species group has the lowest number of ventral and midbody scales of the L. lineomaculatus section. Furthermore, both species possess precloacal pores but these are fewer in number relative to the L. kingii group, and are strongly differentiated from the L. kingii group in both the dorsal and ventral patterns. Sexual dimorphism is not present in either meristic or morphometric characters within this group.

The L. kingii group

With this morphological review, we set up a ‘new’ starting point for the species of this group because the traditional differentiation into two groups ( L. kingii and L. archeforus ) that was not supported by molecular data ( Espinoza et al., 2004; Schulte & Moreno- Roark, 2010; Breitman et al., 2011a, c) is also not supported by the extensive morphological data presented here. Thus, we strongly recommend using the group name L. kingii to refer to the group formed by: L. archeforus , L. baguali , L. chacabucoense , L. escarchadosi , L. gallardoi , L. kingii , L. sarmientoi , L. scolaroi , L. somuncurae , L. tari , L. tristis , L. uptoni , and L. zullyae . Some of these species have relatively large distributions (e.g. L. escarchadosi , L. gallardoi , L. kingii , and L. sarmientoi ), whereas others have more restricted ones (e.g. L. somuncurae , L. tari , L. tristis , and L. uptoni ).

The L. kingii group is differentiated from the L. lineomaculatus and L. magellanicus groups based on molecular and morphological evidence, as described above. Species within the L. kingii group are the largest and present the highest number of scale counts amongst the groups of the L. lineomaculatus section. They also present a different coloration pattern characterized by the presence of transversal bands (complete, broken, or indistinct), but never showing the characteristic dorsal pattern of the L. lineomaculatus and L. magellanicus groups (two paravertebral and quadrangular series of black or brown blotches surrounded by two well-defined, whitish lines). Sexual dimorphism is evident in the meristic as well as in the morphometric characters in the species included in this group.