Tiliqua maculata Gray, 1839

Miralles, Aurélien, Chaparro, Juan Carlos & Harvey, Michael B., 2009, Three rare and enigmatic South American skinks, Zootaxa 2012, pp. 47-68 : 61-62

Status of Tiliqua maculata Gray, 1839 , and designation of a lectotype

Gray (1839) described Tiliqua maculata from Demerara, Guyana. Since its original description, various authors ( Boulenger 1887, Travassos 1946, 1948) considered it as synonymous with Trachylepis atlantica . Recently, Mausfeld & Vrcibradic (2002) examined two syntypes (NHM 1946.8.18.5–6) and strongly suspected that T. maculata is a species distinct from T. atlantica . Comparing the two species, they noted differences in number of dorsal keels, midbody scales, dorsals, ventrals and subdigital lamellae under Finger IV and Toe IV. These authors also concluded that, “ the type locality of maculata should be considered dubious ” as “ some other specimens of lizards and snakes from ‘Demerara’ collected by Capt. Sabine turned out to be restricted to certain Caribbean islands such as St. Kitts and Nevis and Santa Lucia (Underwood 1993), ” and, consequently, “ it is likely that the type locality of maculata is St. Lucia or Barbados. ” These author also speculated that T. maculata might be synonymous with Mabuya falconensis .

When Travassos (1948: 206) reconsidered the status of Gray’s names, he designated a lectotype of Tiliqua punctata . Regrettably, this author did not reference the specimen by its museum number stating only, « aproveito a oportunidade para designar o exemplar macho, com 16,5 mm depositado no Museu Británico como lectótipo […]». This imprecise text misled some subsequent authors such as Bauer (2003) to conclude that a lectotype of T. maculata had been chosen. The measurement Travassos (1948) used to reference the specimen is its head length as indicated in the table he presents on page 207. The head measurement corresponds to the larger syntype; thus Travassos (1948) designate NHM 1946.8.27.47 as the lectotype of Tiliqua punctata Gray. He did not designate a lectotype of T. maculata , which he considered synonymous with T. punctata .

During this study, we examined two of the three types of Tiliqua maculata : NHM 1946.8.18.6 (one of the two NHM types examined by Mausfeld & Vrcibradic, 2002) and MNHN 2932 (a third type housed at the MNHN) and compared them to Trachylepis atlantica , Mabuya falconensis , and various species of Mabuya from the Caribbean (Appendix II). Both specimens are in a very poor state of preservation, a fact noted by Boulenger (1887). Fortunately, Bocourt (1879) illustrated and redescribed MNHN 2932 ( Fig. 7 ). For this reason, it seems appropriate to designate this specimen as the lectotype of Tiliqua maculata Gray , even if it is in a very poor state. The lecotype has 7 supralabials, the fifth below the eye, 15/15 lamellae under the fourth finger, 20/20 lamellae under the fourth toe, 37 ventrals, 58 dorsals, 32 scales around midbody, a pair of primary nuchals (secondary nuchals absent), and 5/5 supraciliaries. To avoid damaging this delicate specimen, we did not measure it, however Brygoo (1985) reported that it has a SVL of 219 mm and an incomplete tail, 125 mm.

Although number of dorsals at midbody falls within the range of Mabuya , Gray’s species has auricular lobules and heavily keeled dorsals. Contact between the third supraocular and frontal also excludes Tiliqua maculata from Mabuya . In the types, these scales narrowly contact one another ( Fig. 6 e, f), whereas they never contact one another in Mabuya . On the other hand, this suite of characters allies Gray’s species with the Afro-Malagasy radiation and we formally transfer it to Trachylepis as Trachylepis maculata (Gray) new combination. This same suite of characters serves to distinguish T. maculata from Mabuya falconensis and its congeners from both the Caribbean and mainland Neotropics. We agree completely with Mausfeld & Vrcibradic (2002) that T. maculata is a species distinct from T. atlantica . However, we do not know if it is synonymous with a species from the Afro-Malagasy region or if it actually once occurred in Guyana. We often think of exotic species as a 20–21st century problem. It is certainly possible that T. maculata was accidentally introduced to the port of Demerara during the transatlantic slave trade period and has since gone extinct. Both Bocourt (1879: 412) and Duméril (Duméril & Duméril 1851) argued that T. maculata is most similar to the African species T. perrotettii : « Nous trouvons parfaitement juste l’appréciation suivante donnée par M. Aug. Duméril (Cat. Méth. 1851, p. 159): « C’est avec l’Euprépis de Perrottet, originaire de la côte occidentale d’Afrique, que cette espèce a le plus de rapport par l’ensemble de ses caractères » ( Bocourt 1879).

Figures

FIGURE 6. Cephalic morphology of Mabuya sensu lato, showing diagnostic features of supraocular and frontal contact in M. bistriata (a, MPEG 14561), M. mabouya (b, Holotype MNHN 5421), Eutropis multifasciata (c, representing the Asian clade, redrawn from Boulenger 1890: 181), Trachylepis tschudii (d, Holotype MHNN 91.2426) and T. maculata (e, NHM 1946.8. 18.6, and f, lectotype, MNHN 2932, redrawn from Bocourt 1879), T. atlantica (g, MNR 1175, redrawn from Travassos, 1946: plate III, fig. 5), Trachylepis quinquetaeniata (h, RMNH 17427 b, redrawn from Hoogmoed, 1974: 48), and Chioninia stangeri (i, syntype NHM 1946.8.2). Numbered scales are the most posterior supraoculars contacting the frontal (F) and frontoparietals (FP).

FIGURE 7. Lectotype (MNHN 2932) of Trachylepis maculata as illustrated by Bocourt (1879, Plate XXII C)