Comptus, Schools & Hedges, 2021

Schools, Molly & Hedges, S. Blair, 2021, Phylogenetics, classification, and biogeography of the Neotropical forest lizards (Squamata, Diploglossidae), Zootaxa 4974 (2), pp. 201-257 : 226-228

Genus Comptus gen. nov.

Caribbean Rough-scaled Forest Lizards

Figs. 15–16

Type species. Diploglossus stenurus, Cope, 1862:188 . Diagnosis. Species of Comptus gen. nov. have (1) claw sheath, absent, (2) contact between the nasal and rostral scales, absent, (3) scales in contact with the nasal scale, four, (4) postnasal scales, one, (5) position of the nostril in the nasal scale, central, (6) keels on dorsal body scales, present, (7) digits per limb, five, (8) longest toe lamellae, 13–23, (9) dorsal scale rows, 88–107, (10) relative head width, 11.9–15.0, (11) relative rostral height, 53.2–65.5, (12) relative frontonasal length, 2.95–3.65, (13) relative interparietal distance, 0–0.435, (14) relative axilla-groin distance, 51.9–60.0.

From Advenus gen. nov., Comptus gen. nov. is distinguished by the claw sheath (absent versus its presence in Advenus gen. nov.), keels on dorsal scales (present versus their absence in Advenus gen. nov.), relative rostral height (53.2–65.5 versus 50.1), relative frontonasal length (2.95–3.65 versus 2.46), and the distance between the parietal scales (0–0.435 versus 0.632). From Caribicus gen. nov., we distinguish Comptus gen. nov. by the relative interparietal distance, (0–0.435 versus 0.468–1.42) and the relative axilla-groin distance (51.9–60.0 versus 67.1– 69.1). From Celestus , we distinguish Comptus gen. nov. by the relative axilla-groin distance (51.9–60.0 versus 60.9–66.4). From Panolopus , we distinguish Comptus gen. nov. by keels on the dorsal scales (present versus their absence in Panolopus ), relative rostral height (53.2–65.5 versus 37.6–51.9), and the relative frontonasal length (2.95–3.65 versus 1.93–2.94). From Sauresia , we distinguish Comptus gen. nov. by the claw sheath (absent versus its presence in Sauresia ), keels on the dorsal body scales (present versus their absence in Sauresia ), digits per limb (five versus four), the longest toe lamellae (13–23 versus 8–12), the relative frontonasal length (2.95–3.65 versus 1.70–2.56), and the relative axilla-groin distance (51.9–60.0 versus 63.9–69.9). From Wetmorena , we distinguish Comptus gen. nov. by the claw sheath (absent versus its presence in Wetmorena ), keels on the dorsal body scales (present versus their absence in Wetmorena ), digits per limb (five versus four), longest toe lamellae (13–23 versus 8–12), the relative frontonasal length (2.95–3.65 versus 1.47–2.69), and the distance between the parietal scales (0–0.435 versus 0.447–1.03).

Content. Three species ( Table 3 ): Comptus badius , C. maculatus , and C. stenurus .

Distribution. Comptus gen. nov. occurs in the Cayman Islands, Navassa Island, and throughout most of Hispaniola, including the associated islets of Ile-a-Vache, Île à Cabrit, and Ile Grande Cayemite ( Fig. 16 ).

Etymology. The generic name ( Comptus ) is a Latin masculine noun meaning adornment, referring to the keeling of the dorsal scales in this genus.

Remarks. Comptus gen. nov. is a monophyletic clade that has a support value of 100% in Bayesian and ML analyses ( Fig. 2 ). Our phylogenetic tree includes all three species of Comptus gen. nov. and three of the four subspecies of Comptus stenurus ( C. stenurus rugosus , C. stenurus stenurus , and C. stenurus weinlandi ), missing only Comptus stenurus alloeides.

Surprisingly, Comptus maculatus from the Cayman Islands, previously considered a subspecies of Celestus crusculus ( Schwartz & Henderson 1991) , a Jamaican species in a different genus, is nested within Comptus stenurus in the molecular phylogeny ( Fig. 2 ). The character completely separating Celestus from Comptus gen. nov., relative axilla-groin distance, supports that finding. The Navassa species, Comptus badius , also is nested within Comptus stenurus . Comptus stenurus is not monophyletic and includes populations with deep divergences (3.1 Mya; Fig. 3 ). These results, together with other molecular and morphological data, indicate that the genus Comptus includes at least three additional species (Schools & Hedges, unpubl.).

Figures

FIGURE 2. Phylogenetic tree of diploglossid lizards based on sequences of nine genes: four mitochondrial genes (CytB, ND2, 12S rRNA, and 16S rRNA) and five nuclear genes (AMEL, BDNF, PLPR, RAG1, and ZFP36). Maximum likelihood tree obtained from the nine-gene dataset (59 individuals; 6,949 sites).A scale bar indicates 5% sequence divergence. The numbers at nodes are ML bootstrap values, followed by Bayesian posterior probabilities; asterisks indicate significant (≥ 95%) support, and a dash or zero value indicates weak (<50%) support. The tree is rooted with Pseudopus apodus (Anguidae).

FIGURE 3. Timetree of Diploglossidae based on sequences of nine genes: four mitochondrial genes (CytB, ND2, 12S rRNA, and 16S rRNA) and five nuclear genes (AMEL, BDNF, PLPR, RAG1, and ZFP36). Nodes show divergence times in millions of years. A scale bar indicates time (6 million years ago, Mya). We show Bayesian credibility ranges as gray bars at nodes.

FIGURE 15. In life images of (A) Comptus badius (Voucher not available, SBH 194991, United States) (B) Comptus maculatus (ANSP 38511, SVL 49.7 mm) and (C) Comptus stenurus (ANSP 38538, SVL 123 mm). Photographs by S. B. Hedges.

FIGURE 16. The distribution of Comptus gen. nov. Arrows indicate distributions on Little Cayman, Cayman Brac, Navassa Island, Grande Cayemite, Île-à-Vache, and Île à Cabrit.