Taxonomic adjustments in the systematics of the southern African lacertid lizards (Sauria: Lacertidae)
Author
Edwards, Shelley
Author
Branch, William R.
Author
Vanhooydonck, Bieke
Author
Herrel, Anthony
Author
Measey, G. John
Author
Tolley, Krystal A.
text
Zootaxa
2013
3669
2
101
114
journal article
10.11646/zootaxa.3669.2.1
1af249de-576e-4b12-abde-9e380cbf0bd3
1175-5326
221968
4A8C9C02-DE18-47B8-8CB7-7F90B89B16AD
Monophyly of
Australolacerta
The two species of
Australolacerta
are endemic to
South Africa
(Branch 1998), and both were originally placed within
Lacerta
, creating a zoogeographic paradox as most congeners were restricted to Eurasia (Arnold 1989). Arnold (1989), when describing
Australolacerta
, gave only a minimal diagnosis, noting that “… the South African species share a number of features with other Ethiopian lacertids which are not found in the apparent closest Palaearctic relatives, namely
Lacerta jayakari
etc.”. The latter, now transferred to
Omanosaura
, was initially considered to form a basal lineage within the Eremiadini (Harris
et al.
1998), although fuller taxon sampling of African lacertids (Arnold
et al.
2007; Hipsley
et al.
2009; Kapli
et al.
2011) shows it to cluster with a suite of mainly north African genera (e.g.
Acanthodactylus
,
Mesalina
,
Ophisops
), with
Atlantolacerta
basal within the Eremiadini (Arnold
et al.
2007). The sister relationship of
Australolacerta
and
Tropidosaura
proposed by Salvi
et al.
(2011) and Kapli
et al.
(2011) was based on the inclusion only of
A. australis
, and the inclusion of
A. rupicola
(Edwards
et al.
2012; Engleder
et al.
2013; this study) revealed the paraphyly of
Australolacerta
and the basal position of
A. australis
in a subclade including
Ichnotropis
,
Tropidosaura
and
A. rupicola
.
Both species are rupicolous and Kirchhof and Richter (2009) and Kirchhof
et al.
(2010a,b; 2012) give details of the species’ biology. They are morphologically similar, albeit that many of these similarities are plesiomorphic within lacertids (Arnold 1989). Due to their high-altitude and small ranges (Branch 1998), the two species have been difficult to collect and therefore little morphological data exists for either species. Recent morphological analyses (Edwards
et al.
2012) confirm the similarity between the two species. Yet, important features of hemipenial ornamentation and everted hemipenis structure remain unknown. Whether these similar morphologies reflect adaptive convergence to rupicoly or the retention of plesiomorphic features remains unknown.
The two species are allopatric and geographically separated from one another by a distance of approximately
1700km
. Few other genera in southern Africa are known to show such large geographical disjunctions between congeners, and analysis of previous examples has often revealed deep genetic divergence best reflected in generic re-assignment. Examples include: the erection of the genera
Kinyongia
and
Nadzikambia
for non-South African dwarf chameleons previously included in
Bradypodion
(Tilbury
et al.
2006)
, and
Inyokia
for the problematic Swazi rock snake that was shown to be sister to the tropical forest snake
Homonotus modestus
(Kelly
et al.
2011)
. In one of the few exceptions of congeneric range disjunctions within the subcontinent, cordylid flat lizards of the
Platysaurus capensis
complex are separated geographically from other
Platysaurus
by approximately
850km
(Branch & Whiting 1997). Other described lacertid species are also separated from congeners by large distances, for example
Heliobolus lugubris
is separated from its congeners (
H. spekii
,
and
H. nitidus
) by>
2000km
and
Ichnotropis chapini
is separated from other
Ichnotropis
by approximately
2000km
(Branch, 1998; Spawls
et al
. 2002). However, the Central African region is undersampled and it is possible that with increased sample collection new species may be discovered or that ranges of described species may increase, lessening the geographic gap between congeners.
Although there were no significant differences between the obtained trees and the constrained trees in the SH or AU test when the topology was constrained to monophyly for
Australolacerta
sequence divergence estimates and the long branch lengths in the phylogenetic analyses (
Figure 1
) all other evidence strongly suggests that the two
Australolacerta
species do not share a recent evolutionary history (Edwards
et al.
2012).To provide consistency between taxonomic divisions in the Eremiadini, we propose that the two species of
Australolacerta
should be placed in separate genera. The
type
species of
Australolacerta
is
Lacerta australis
(Arnold 1989)
, and we therefore erect a new genus for the remaining species
Lacerta rupicola
, based on morphology and genetic divergence.