Brookesia tedi, Scherz & öhler & Rakotoarison & Glaw & Vences, 2019

Scherz, Mark D., oehler, Joern, Rakotoarison, Andolalao, Glaw, Frank & Vences, Miguel, 2019, A new dwarf chameleon, genus Brookesia, from the Marojejy massif in northern Madagascar, Zoosystematics and Evolution 95 (1), pp. 95-106 : 96-101

Brookesia tedi sp. n. Figures 5 , 6 , 7 ; Table 1

Remark.

This species has been previously referred to as follows:

B. " Brookesia minima " - Brygoo et al. (1974)

B. minima s. l. - Brygoo and Domergue (1975)

B. aff. minima - Brygoo (1978)

B. cf. minima - Glaw and Vences (1994)

Possibly also within the definition of B. minima by Raxworthy and Nussbaum (1995); see Referred specimens below.

Holotype.

ZSM 438/2016 (ZCMV 15262), adult male, collected on 18 November 2016 in Camp ‘Simpona’ (Camp 3) of Marojejy National Park (ca 14.4366S, 49.7434E, 1325 m a.s.l.), Sava Region, northeastern Madagascar by M.D. Scherz, A. Razafimanantsoa, A. Rakotoarison, M. Bletz, M. Vences, and J.H. Razafindraibe.

Paratype.

ZSM 439/2016 (ZCMV 15298), adult male, collected on 20 November 2016 from the same locality and by the same collectors as the holotype.

Referred specimens.

Four specimens of Brookesia aff. minima ( MNHN 1986.876-879, formerly all subsumed under the preliminary number 722/C, sex unidentified), formerly housed in the Collection of the Institut Pasteur de Madagascar, were apparently collected ('event date’) on 4 December 1972 at ‘Marojezy’ (=Marojejy), 1300 m a.s.l. according to the VertNet database (http://portal.vertnet.org/search, accessed 25 December 2018) and are probably the specimens referred to by Brygoo et al. (1974); we tentatively refer these specimens to this species without having examined them. The whereabouts of additional potential specimens (no. 722 and 723c) and of the ca 40 specimens collected by G. Ramanantsoa reported by Brygoo (1978) is unknown.

Specimens UMMZ 203615-203621 reported by Raxworthy and Nussbaum (1995) to be identical to B. minima may also be attributable to this species, but apparently come from lower elevation (200-800 m a.s.l.) and therefore cannot be referred to this species until they are genetically and morphologically investigated. In any case, given the morphological variation of B. tedi (see Discussion below) and the presence of one other species of the B. minima group at Marojejy ( B. karchei ), the identification of all these additional specimens as B. tedi will remain tentative unless molecular data can be obtained or fully diagnostic morphological or osteological characters defined in the future.

Diagnosis.

A diminutive chameleon species assigned to the genus Brookesia on the basis of its small body size, short tail, crests of the head, dorsolateral spines and molecular relationships. Brookesia tedi sp. n. is morphologically characterised by the following unique suite of characters (n = 2 males): (1) SVL 15.3-18.2 mm; (2) TaL/SVL 0.74-0.92; (3) TL 29.5-31.7 mm; (4) HW/SVL 0.20-0.21; (5) 8-10 dorsolateral spines (when countable; sometimes spines are not or are only partly expressed, rendering them difficult to count); (6) distinct pelvic spine; (7) absence of lateral or dorsal spines on the tail; (8) presence of supraocular cone; (9) presence of supranasal cone; and (10) rather globular hemipenis with paired sets of small fleshy apical papillae.

Within the genus Brookesia , B. tedi sp. n. can easily be distinguished from all species that are not members of the B. minima species group based on its diminutive size (SVL 15.3-18.2 mm vs minimum 34 mm). Within the B. minima species group, it can be distinguished from males of B. tristis by longer relative tail length (TaL/SVL 0.74-0.92 vs 0.71-0.72), presence of supraocular cone (vs. absence); from males of B. confidens by slightly smaller body size (SVL 15.3-18.2 vs 18.3-20.1 mm), longer relative tail length (TaL/SVL 0.74-0.92 vs 0.60-0.70), presence of supraocular cone (vs absence), and globular hemipenes (vs tubular); from males of B. micra by longer relative tail length (TaL/SVL 0.74-0.92 vs 0.47-0.49), slightly narrower relative head width (HW/SVL 0.20-0.21 vs 0.23), slightly smaller relative head height (HH/SVL 0.16-0.18 vs 0.19-0.20), and globular hemipenes with paired fleshy apical papillae (vs tubular hemipenes with apical combs of papillae); from males of B. desperata by smaller body size (SVL 15.3-18.2 vs 25.0-26.7 mm) and total length (TL 29.5-31.7 vs 39.7-42.9 mm), longer relative tail length (TaL/SVL 0.74-0.92 vs 0.59-0.63), absence of lateral tail spines (vs presence), fewer dorsolateral spines (8-10 when countable vs 12-14), and hemipenes with fleshy papillae (vs single spines on strongly bilobed apex); from the male holotype of B. exarmata as reported by Schimmen ti and Jesu (1996) by the presence of a supraocular cone (vs absence), slightly smaller relative head height (HH/SVL 0.16-0.18 vs 0.23), and slightly smaller total length (TL 29.5-31.7 vs 33.3 mm); from males of B. minima by slightly longer relative tail length (TaL/SVL 0.74-0.92 vs 0.65-0.73), slightly wider relative head width (HW/SVL 0.20-0.21 vs 0.16-0.19), presence of supraocular cone (vs absent), and presence of a distinct pelvic spine (vs absent or indistinct); from males of B. ramanantsoai by smaller body size (SVL 15.3-18.2 vs 21.7 mm) and total length (TL 29.5-31.7 vs 39.0 mm), and wider relative head width (HW/SVL 0.20-0.21 vs 0.16); from males of B. dentata by smaller total length (TL 29.5-31.7 vs 43 mm) and presence of supraocular cone (vs absent); from females of B. karchei (as reported by Glaw et al. 2012a; no data from males are available) by longer relative tail length (TaL/SVL 0.74- 0.92 vs 0.66), slightly wider relative head width (HW/SVL 0.20-0.21 vs 0.17), absence of lateral tail spines (vs presence), and fewer dorsolateral spines (8-10 when countable vs 13); and from males of B. tuberculata by smaller supraocular cone and globular hemipenis (vs tubular).

Molecular data clearly identify B. peyrierasi as the sister species of B. tedi sp. n. (Figs 1 , 2 ); from males of B. peyrierasi the new species is distinguished by smaller body size (SVL 15.3-18.2 vs 19.7-22.4 mm) and total length (TL 29.5-31.7 vs 34.2-39.8 mm), more distinct supraocular cone, and rather globular hemipenis lacking apical spines (vs tubular hemipenis with paired sets of apical spines; Fig. 6 ).

Description of the holotype.

Adult male in good state of preservation (Figs 5 , 7 ). Both hemipenes everted. Measurements in Table 1 . Lateral crest on head weakly devel oped, barely recognizable; prominent orbital crests, and a transverse row of enlarged tubercles at the posterior edge of the head that separates the head from the body, no distinct posterior crest; a pair of curved parasagittal crests that start above the eyes and begin to converge before terminating at the transverse row of enlarged tubercles; depression between the eyes with short longitudinal median crest; three pointed tubercles on each side of posterior margin of head; scattered slightly enlarged tubercles on lateral surfaces of head; orbital crest denticulated; distinct supraocular cone present; supranasal cone small, not projecting beyond snout tip; head longer (5.1 mm) than wide (3.2 mm); chin and throat with evenly spaced distinctly enlarged tubercles. Dorsal surface of body without a vertebral ridge or keel; 10/8 (left/right) dorsolateral spines (pointed tubercles) form an almost complete longitudinal line on the body; posteriormost pointed dorsolateral tubercle being largest, above insertion point of hindlimb (the pelvic spine), very slightly projecting backwards; no dorsal pelvic shield in sacral area, but distinct pelvic spine; pointed dorsolateral tubercles almost equally spaced, except for first three tubercles on left side; dorsal surface of tail lacking distinctly enlarged tubercles; scattered enlarged tubercles laterally on anterior third of tail; lateral surface of body with evenly spaced enlarged rounded tubercles; venter with distinctly enlarged rounded tubercles; scattered, distinctly pointed tubercles on limbs; no pointed tubercles around cloaca; longitudinal row of slightly enlarged tubercles lateral on anterior tail; no dorsal, lateral or ventral spines on tail; no enlarged tubercles on ventral surfaces of tail.

The hemipenis is rather globular (though not as globular as that of B. minima ), short and broad, with a flattened apical end with a clear lip around its circumference (Fig. 6 ). The whole of the apex is somewhat tilted sulcally. A pair of structures emerge from the apical surface, each of which consists of three fleshy lobes, of which the middle lobe is the shortest. The truncus is smooth and lacks any trace of calyces.

In life, overall colouration light to dark brown, lighter ventrally, the dorsal head and dorsum down to the tail grey. Tubercles and patches of various other colours, including a number of nearly black spots, dot the flanks. Rectangular patches of grey invade the flank from the dorsum. The eye is rayed in shades of brown, with three especially light rays ventrally, the anterior two of which traverse across the upper and lower lips. A brown stripe bordered with cream traverses the supraocular cones. The limbs are distinctly darker than the body. For further detail, see Figure 7 . After two years in ethanol, the body colour is muted and more homogeneous. The rays on the eye and stripe between supraocular cones are still distinct, but the grey invading the flanks from the dorsum is less distinct.

Variation.

For morphological measurements and proportions see Table 1 . The male paratype ZSM 439/2016 differs from the male holotype by a far more prominent supraocular crest, formed by six large pointed tubercles, including a large supraocular cone; by three parallel dorsal crests between parasagittal crests; less prominent enlarged tubercles on throat, chin and venter; indistinct and smaller dorsolateral tubercles (not reliably countable), and a prominent enlarged pointed tubercle on lateral side of head. Its hemipenes are less well extruded than those of the holotype, and the fleshy apical lobes, although present, are difficult to identify.

Etymology.

The species name is a patronym dedicated to Ted Townsend, in recognition of his important contributions to the phylogenetics and systematics of squamates, chameleons, and Brookesia in particular.

Conservation status.

This species is currently only known from relatively high elevation on the Marojejy massif. We follow assessments for other chameleon endemics from this area on Marojejy, specifically Calumma jejy and C. peyrierasi , which are found somewhat higher but probably have a similar level of microendemism. We consider the species Vulnerable under IUCN Red List criterion Vulnerable D2: as far as is known, B. tedi has a highly restricted area of occupancy (= extent of occurrence) of under 150 km2 (this is the area of 1200 m a.s.l. and above in Marojejy), and is known from a single threat-defined location at 1300 m a.s.l. and above in Marojejy National Park. Two plausible future threats, namely decrease in efficacy of protection on Marojejy, and fire, could rapidly drive the species to becoming Critically Endangered.

Figures

Figure 1. Molecular phylogenetic trees of species in the Brookesia minima group, based on sequences of the mitochondrial 16 S (480 bp) and ND 2 (574 bp) genes, inferred under the Maximum Likelihood optimality criterion, and the GTR + G (16 S) and HKY + I + G (ND 2) substitution models. Values at nodes are support values from a bootstrap analysis in percent (500 replicates) and are shown only if> 50 %. The two gene fragments were analysed separately and not concatenated because partly different samples were available for each of them. The trees were rooted with Brookesia brygooi (removed for better graphical representation).

Figure 2. Molecular phylogeny of species in the Brookesia minima group, based on the nuclear c-mos gene (405 bp, no missing data) and inferred under the Maximum Likelihood optimality criterion (K 2 substitution model). Values at nodes are support values from a bootstrap analysis in percent (500 replicates) and are only shown if> 50 %. The tree was rooted with Brookesia brygooi (removed for better graphical representation).

Figure 5. The holotype of Brookesia tedi sp. n. from Marojejy in lateral view (above), and dorsal (middle) and lateral (below) views of the heads of the types of B. tedi sp. n., in comparison with a representative male specimen of B. peyrierasi from the type locality Nosy Mangabe. The lateral view of the holotype (marked with an asterisk) has been mirrored to be in the same orientation as those of the other specimens. Scale bar: 1 mm.

Figure 6. The preserved hemipenes of Brookesia tedi sp. n. and its sister species, B. peyrierasi in sulcal view. Not to scale. Note that the spines of B. peyrierasi are equally visible in asulcal view, and in all studied individuals of this species (see Glaw et al. 1999).

Figure 7. Different views of the holotype of Brookesia tedi sp. n. (ZSM 438 / 2016; field number ZCMV 15262) in life.