Caribicus, 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 : 218-220

Genus Caribicus gen. nov.

Northern Hispaniola Forest Lizards

Figs. 8–9

Type species. Celestus darlingtoni Cochran, 1939:2 .

Diagnosis. Species of Caribicus 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, 12–19, (9) dorsal scale rows, 80–233, (10) relative head width, 13.6–17.2, (11) relative rostral height, 39.7–58.3, (12) relative frontonasal length, 2.98–3.32, (13) relative interparietal distance, 0.468–1.42, (14) relative axilla-groin distance, 67.1–69.1.

From Advenus gen. nov., we distinguish Caribicus gen. nov. by the claw sheath (absent versus its presence in Advenus gen. nov.), keels on the dorsal scales (present versus their absence i n Advenu s gen. nov.) ), relative head width (13.6–17.2 versus 12.0), relative frontonasal length (2.98–3.32 versus 2.46), and the relative axilla-groin distance (67.1–69.1 versus 60.0). From Celestus , we distinguish Caribicus gen. nov. by the relative axilla-groin distance (67.1–69.1 versus 60.9–66.4). From Comptus gen. nov., we distinguish Caribicus gen. nov. by the relative interparietal distance(0.468–1.42 versus0–0.435), and the relative axilla-groin distance(67.1–69.1 versus51.9–60.0). From Panolopus , we distinguish Caribicus gen. nov. by keels on the dorsal body scales (present versus their absence in Panolopus ), relative frontonasal length (2.98–3.32 versus 1.93–2.94), and the relative axilla-groin distance (67.1– 69.1 versus 49.7–59.6). From Sauresia , we distinguish Caribicus 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), relative head width (13.6–17.2 versus 9.36–12.2), relative frontonasal length (2.98–3.32 versus 1.70– 2.56), and the distance between the parietal scales (0.468–1.42 versus 0–0.431). From Wetmorena , we distinguish Caribicus gen. nov. by the claw sheath (absent versus its presence in Wetmorena ), keels on the dorsal scales (present versus their absence in Wetmorena ), digits per limb (five versus four), and the relative frontonasal length (2.98–3.32 versus 1.47–2.69).

Content. Three species ( Table 3 ): Caribicus anelpistus , C. darlingtoni , and C. warreni .

Distribution. Caribicus gen. nov. occurs on the geological North Island of Hispaniola and adjacent Ile de Tortue ( Fig. 9 ).

Etymology. The generic name ( Caribicus gen. nov.) is a masculine noun derived from the name for the region (Caribbean) in which it occurs and the suffix - icus (“belonging to”).

Remarks. Caribicus gen. nov. is a monophyletic clade that has a support value of 100% in Bayesian and ML analyses ( Fig. 2 ). Our phylogenies do not include C. anelpistus . That species and C. warreni are both giant (up to 279 mm SVL) whereas C. darlingtoni is much smaller (up to 85 mm SVL) and was never thought to be closely related to the giant species. For many years, the giant species were placed in Diploglossus and the small species was placed in Celestus ( Schwartz & Henderson, 1991) .

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 8. In life images of (A) Caribicus darlingtoni (USNM 328807, SVL 45.5 mm) and (B) Caribicus warreni (Voucher not available, SBH 194521, SVL 263 mm). Photographs by S. B. Hedges.

FIGURE 9. The distribution of Caribicus gen. nov. on Hispaniola.