Historical and fossil evidence of an extinct endemic species of Leiocephalus (Squamata: Leiocephalidae) from the Guadeloupe Islands
Author
Bochaton, Corentin
0000-0003-4954-0019
PACEA-UMR CNRS 5199, Université de Bordeaux, 33 615 Pessac, France. & Max Planck Institute for the Science of Human History, Department of Archaeology, Kahlaische StraSSe 10, 07745 Jena, Germany. corentin. bochaton @ u-bordeaux. fr; https: // orcid. org / 0000 - 0003 - 4954 - 0019
corentin.bochaton@u-bordeaux.fr
Author
Charles, Laurent
Muséum de Bordeaux-sciences et nature, 5 Place Bardineau, Bordeaux 33 000, France.
Author
Lenoble, Arnaud
0000-0001-9023-9741
PACEA-UMR CNRS 5199, Université de Bordeaux, 33 615 Pessac, France. & arnaud. lenoble @ u-bordeaux. fr; https: // orcid. org / 0000 - 0001 - 9023 - 9741
arnaud.lenoble@u-bordeaux.fr
text
Zootaxa
2021
2021-02-15
4927
3
383
409
journal article
8188
10.11646/zootaxa.4927.3.4
143982dd-c519-4cd4-9207-e15a33f940b9
1175-5326
4542332
6F654F5C-1704-4AC5-B711-94C45B67A513
Leiocephalus roquetus
sp. nov.
Fig. 2
,
3
,
4
,
5
,
6
,
7
Diagnosis.
Leiocephalus roquetus
differs from all other congeners by the morphology of its parietal bone that bears adductor crests fused into a single crest in the posterior area of the bone in large specimens. In addition of this character,
L. roquetus
presents a unique combination of characters: absence of enlarged snout scales, and occurrence of five scales in contact with the first pair of enlarged frontal scales (pattern of
type
I of
Pregill (1992))
, the occurrence of three internasal scales, a prominent dorsal body crest, absence of keeled ventral scales, frontal bone exposed dorsally between the nasal and prefrontal bones, skull rugosities on the frontal bone, premaxillary spine constricted just above the dentigerous process, a well-developed posterior process of the septomaxilla, a distinct dorsal process of the squamosal, a well-developed angular process of the dentary, and transition from bicuspid to tricuspid teeth occurs between the height and sixth most anterior dental position of the dentary. This new taxon also presents several differences with other known Lesser Antillean
Leiocephalus
specimens (see below).
Derivatio nominis
: The species is named in reference to the first common name “roquet” attributed by
Du Tertre (1654)
and
de Rochefort (1658)
to the leiocephalid lizards of
Guadeloupe
. As pointed out by
Breuil (2002)
, this name was latter erroneously attributed to
Anolis
lizards and, as the Amerindian name of
Leiocephalus
is unknown, we choose to retain the original name given to these squamates. The English name of this lizard would be “Curlytail roquet” and the French name “Léiocéphale roquet”.
FIGURE 2.
Dorsal (A) and ventral (B) views of the complete holotype specimen of
Leiocephalus roquetus
sp. nov.
(MHNBx 2002.1871). Scale bar= 5 mm.
FIGURE 3.
Head and skull of the Holotype of
Leiocephalus roquetus
sp. nov.
(MHNBx 2002.1871). A, B: Picture and drawing of the dorsal scales of the head of the Holotype; C, D: Picture and drawing of the lateral scales of the head of the Holotype; E, F: Dorsal and lateral views of the 3D model of the skull of the holotype; G: Labial and lingual views of the 3D model of the right mandible of the holotype. Scale bars= 3 mm.
Type
locality
:
Guadeloupe
,?
La Désirade Island
,
Lesser Antilles
.
General description of the
holotype
.
The
holotype
is a complete, dry taxidermy specimen (labeled MHNBx 2002.1871) preserved in the Natural History Museum of Bordeaux (
France
). This specimen has a snout-vent length (SVL) of
10.8 cm
and measures
26.5 cm
in total length (
Fig. 2
). Microtomography reveals the skull to be fully preserved (
Fig. 3
). The key morphological features of the
holotype
are as follows: enlarged nasal bones, the narrow nasal process of the premaxilla is triangular, the dorsal part of the premaxilla is fully enclosed by the nasal bones, the premaxilla lacks lateral spines and bears 7 tooth positions, the nasal-maxillary suture is arched toward the midline of the snout, the nasal process of the frontal bone is dorsally exposed between the nasal and prefrontal bones, the pterygoid bears teeth but palatine teeth are absent, lacrimal and postfrontal bones are present, the septomaxilla bears a quadrangular lateral wing with a thin posteriorly oriented process, the frontal is narrow with dermal ornamentation, the parietal foramen is on the fronto-parietal suture, the adductor crests of the parietal table converge but do not touch and are posteriorly separated by a depressed area, the anterior part of the parietal table presents a dermal ornamentation, the supratemporal bone is on the lateral side of the supratemporal process of the parietal, the supratemporal process of the squamosal is distinct, splenial and angular bones are present, the angular process of the dentary is well-developed, most of the teeth are tricuspid and distinctively flared, the transition from monocuspid/bicuspid to tricuspid teeth occurs at the seventh dental position on the dentary and at the fourth dental position on the maxilla. Head scales are large, the specimen presents four rows of snout scales of sub-equal size between the internasal and the anterior pair of frontal scales, there are four moderately-sized parietal scales and the most lateral scales are smaller than the median scales, two rows of post parietal scales are present, there is no enlarged lateral post-parietal scale, there are three internasal scales, there are four lorilabial scales anterior to the first lorilabial contacting the elongated sub-ocular scale, the cephalic scales lack ridges, the temporal scales are of sub-equal size and no elongated temporal scales are present, the lateral nuchal scales are smaller than surrounding body scales, the lateral body scales are the same size as dorsal and ventral scales, a prominent middorsal body crest formed by overlapping scales is present, the dorsal crest (occiput to vent) is composed of 53 scales, the tricarnate scales at the base of the first and second toes grow into comb-like fringes but are not prominent, the venter is dull and patternless, there is no scapular patch, no suprascapular blotches, no facial band, and the base of tail is laterally compressed.
Description of
paratype
fossil bones and corresponding bones of the
holotype
.
In addition to the
holotype
dry specimen, we associate, as
paratypes
, several fossil bones collected from the Pointe Gros Rempart 6 deposit to the type series of
L. roquetus
. These bones are described below in association with corresponding bones of the
holotype
specimen in order to demonstrate that both modern and fossil materials correspond to the same taxon.