Three rare and enigmatic South American skinks
Author
Miralles, Aurélien
Author
Chaparro, Juan Carlos
Author
Harvey, Michael B.
text
Zootaxa
2009
2012
47
68
journal article
10.5281/zenodo.185813
6ee20fb6-5029-4ff7-9a65-1c01f1ba7355
1175-5326
185813
Status of
Trachylepis (Xystrolepis) punctata
Tschudi, 1845
In 1845, Tschudi described
Trachylepis
(
Xystrolepis
)
punctata
from the “
Waldregion
” (= Amazonia) of
Peru
. Although
Roux (1907)
later redescribed the
holotype
and only known specimen, this species has remained enigmatic. Based on its morphology, some authors considered it to be synonymous with
Trachylepis atlantica
(e.g.,
Travassos, 1946
), whereas, based on the
type
locality, others (e.g.,
Peters & Donoso-Barros, 1970
) concluded that it must be synonymous with one of the Amazonian
Mabuya
. In his “
Notes on American Mabuyas,
”
Dunn (1936: 557)
remarked that he was “unable to say what it is.”
Peters and Donoso-Barros (1970)
added Tschudi’s species to the unwieldy synonymy of
M. mabouya mabouya
(Lacépède)
where it has remained until the present day. In this section, we consider the generic allocation of Tschudi’s species, correct its secondary homonymy, and propose some possible explanations for its provenance.
During this study, we examined recent photographs of the
holotype
and only known specimen of
Trachylepis punctata
. The
holotype
(MHNN 91.2426) is housed in the Museum of Neuchâtel in
Switzerland
and is in very poor condition. This specimen cannot be assigned to the genus
Mabuya
, because it has 5/5 auricular lobules, tricarinate dorsal scales in 39 rows at midbody, and the third supraocular in contact with the frontal. Species of
Mabuya
lack auricular lobules and have smooth to finely striated scales in 24–34 rows at midbody (
Table 4
). Among
Mabuya
, the second (in
M. agilis
,
M. agmosticha
,
M. altamazonica
,
M. berengerae
,
M. bistriata
,
M. carvalhoi
,
M. croizati
,
M. falconensis
,
M. frenata
,
M. guaporicola
,
M. lineolata
,
M. luciae
,
M. macleani
,
M. macrorhyncha
,
M. meridensis
,
M. nigropalmata
,
M. nigropunctata
,
M. pergravis
,
M. sloanii
, and
M. unimarginata
) or, rarely, the first (in species having the first and second supraoculars fused into a single scale, such as
M. cochabambae
,
M. dorsivittata
, and
M. mabouya
)
supraocular contacts the frontal (
Greer and Broadley, 2000; personal observation,
Fig. 6
). These characteristics of
T. punctata
are common among species of the Afro-Malagasy radiation (
Hoogmoed 1974
; Mausfeld
et al.,
2002), now comprised of the genera
Trachylepis
and
Chioninia
, and we here formally recognize Tschudi’s species as a member of
Trachylepis
.
In 1845, three different species of
Trachylepis
had been assigned the same specific epithet.
Andersson (1900)
first noted the homonymy between
Tiliqua punctata
Gray
and
Lacerta punctata
Linnaeus
[currently considered a junior synonym of
Trachylepis homalocephala
(Wiegmann)
from the Cape province,
South Africa
] and
Schmidt (1945)
proposed the replacement name
Mabuya atlantica
for Gray’s species (see Mausfeld and Vrcibradic, 2002, for a recent discussion of the nomenclature of the skink on Fernando de Noronha,
Brazil
). However, the homonymy of Tschudi’s name has never been corrected. In accordance with articles 52 and 60 of
the Code
(
ICZN, 1999
), we propose
Trachylepis tschudii
new name
as a replacement for
Trachylepis
(
Xystrolepis
)
punctata
Tschudi. The
new name is a patronym for Dr. J. J. von Tschudi, who originally described this species.
Because of the poor state of the
holotype
, it may be impossible to unequivocally assign it to an existing species of
Trachylepis
. However, the specimen’s supposed origin in the Peruvian Amazon is difficult to believe, considering that the upper Amazon is so far from the Brazilian coast and no additional specimens of any
Trachylepis
have ever been collected in Amazonia. Three mutually exclusive hypotheses may explain the provenance of the specimen:
(1)
Trachylepis tschudii
is actually a very rare Amazonian species. Skinks from this genus have certainly crossed the Atlantic before (
Carranza & Arnold 2003
; Mausfeld
et al
. 2002) as demonstrated by the presence of
T. atlantica
on Fernando do Noronha,
Brazil
, and
T. tschudii
may have dispersed across Amazonia in a manner similar to another African lizard,
Hemidactylus mabouia
(
Kluge, 1969
;
Powell
et al
., 1998
).
(2)
Trachylepis tschudii
actually occurs somewhere in the Old World and the
holotype
was mislabeled.
(3) As proposed by
Travassos (1946)
,
Trachylepis tschudii
is a junior synonym of
T. atlantica
. Assuming the specimen was mislabeled, the
holotype
actually would have been collected on Fernando de Noronha Island,
Brazil
. Or, if the
holotype
was actually collected in the Peruvian Amazon, the skinks from Fernando de Noronha have dispersed into Amazonia, again, similar to
Hemidactylus mabouia
.
We suspect that the third hypothesis is correct. Like
Trachylepis atlantica
,
T. tschudii
has the supernasals, prefrontals, and parietals in contact. Its body dimensions (SVL
83 mm
, tail incomplete, head length
10 mm
, head width 6.5 mm, according to
Roux 1907
), coloration, and scale counts all fall within the variation for this species (Mausfeld and Vrcibradic, 2002;
Travassos, 1946
). Tschudi’s skink is unlikely to be a specimen of
T. maculata
(characteristics in parentheses), because it has three keels on its dorsals (five), 39 scales at midbody