Chelonoidis dominicensis, Albury & Franz & Rimoli & Lehman & Rosenberger, 2018

Albury, Nancy A., Franz, Richard, Rimoli, Renato, Lehman, Phillip & Rosenberger, Alfred L., 2018, Fossil Land Tortoises (Testudines: Testudinidae) from the Dominican Republic, West Indies, with a Description of a New Species, American Museum Novitates 2018 (3904), pp. 1-28 : 7-9

Chelonoidis dominicensis , n. sp.

Figures 2–8 , tables 1–2

HOLOTYPE: MHD 1000 , adult male, with complete carapace and plastron (separated at the bridge), skull, cervical vertebrae, scapula (L/R), coracoid (L/R), humerus (L/R), radius (L/R), ulna (L/R), pelvic girdle (L/R), femur (L), tibia (L), fibula (L). All material appears to represent a single individual. The holotype is on loan to the FLMNH.

TYPE LOCALITY: Oleg’s Bat Cave (= Oleg’s Bat House ), 7 km west and inland of Bavaro in the La Altagracia Province, located on the southeastern coast of the Dominican Republic. The approximate coordinates in WGS84 Datum are N 18°42′, W 68°32′ (fig. 1). The elevation of the cave entrance is 22 m above sea level. Property owners are Frank and Jack Guerrero Herrera. The specimen was discovered by Oleg Shevchuk and collected by Cristian Pittaro and Phillip Lehman.

AGE: We suspect that the tortoise from Oleg’s Bat Cave is probably Late Quaternary. Radiocarbon dates have not been obtained from this tortoise.

PROVENIENCE: The tortoise was found in the flooded La Tortuga section of Oleg’s Bat Cave, totally buried in silt (fig. 2), approximately 147 m from the nearest entrance. The discovery occurred when a fortuitous fin kick by a cave diver removed silt that was covering the dorsal portion of the carapace. Recovery required several dives to acquire the entire specimen. The only damage to the shell was a single crack in the carapace. The skull and postcranial bones were found in association with the shell. Photos and a video (8:11 min) by Pittaro and Lehman show the retrieval of the specimen. These images are archived on Vimeo (https://vimeo. com/197976404). Phillip Lehman brought the specimen to the attention of A.L.R., who alerted N.A.A. and R.F. of its discovery. It was brought to the AMNH for final reconstruction and study with permissions from R.R. and MHD . This specimen was thoroughly studied by N.A.A. and R.F., on 18–21 January 2016, while it was in residence at the AMNH .

RECONSTRUCTION NOTES: The shell of MHD 1000 was separated along natural sutures after recovery. It was transported in pieces from the MHD and to the United States for reconstruction and study. Ana Balcarcel, AMNH Department of Vertebrate Paleontology, completed the preparation process by hardening the material, and molding and casting the carapace. Balcarcel’s notes accompanied the prepared specimen: “Carapace was in-filled with Whitman Fibrous Cellulose powder and Paraloid B- 72 in acetone. It was consolidated with Butvar B-76 throughout (several applications). Fills are white and serve to stabilize the carapace, reducing the risk of fracturing. If desired, fills could be removed with acetone solvent, which softens the fill and allows for it to be extracted manually. Two casts were made with polyester resin for the Dominican Republic and Rosenberger.”

ETYMOLOGY: We take pleasure in naming this new fossil tortoise from the La Altagracia, Dominican Republic, Chelonoidis dominicensis in honor of the people of the Dominican Republic.

Figures

FIGURE 2. Photos of Oleg’s Bat Cave. A. Main cavern. B. Cave diver examining the MHD 1000 tortoise shell; C. tortoise shell in place before it was collected.

FIGURE 3. Comparative views of the shells of Chelonoidis dominicensis (left column) in A. dorsal view; C. lateral view; E. ventral (plastral) view; and C. alburyorum (right column) B. dorsal view; D. lateral view; F. ventral (plastral) view. Separate scale bars represent 10 cm for each specimen. Scale bars = 10 mm.

FIGURE 4. Outline showing scutes as a solid line; sulci as a double line on Chelonoidis dominicensis: A. carapace, dorsal; B. plastron, ventral; C. carapace, right lateral. Abbreviations followed by roman numerals indicate bone order in a series. Bones = black; scutes = red. Carapace bones: cos, costal; neu, neural; nuc, nuchal plate; per, peripheral; pyg, pygal; spy I, suprapygal I; spy II, suprapygal II. Plastron bones: epi, epiplastron; ent, entoplastron; hyo, hyoplastron; hyp, hypoplastron; xip, xiphiplastron. Carapace scutes: mar, marginal; ple, pleural; scd, supracaudal; ver, vertebral. Plastron scutes: abd, abdominal; ana, anal; axi, axillary; fem, femoral; gul, gular; hum, humeral; ing, inguinal; pec, pectoral.

FIGURE 5. Internal views of the plastron of Chelonoidis dominicensis (upper panels) showing: A. complete plastron; B. close-up of anterior plastral lobe; C. posterior plastral lobe. Comparative views of C. alburyorum (lower panels; specimen T4) showing D. complete plastron; E. close-up of anterior plastral lobe; F. posterior plastral lobe.

FIGURE 6. Internal views of carapace of Chelonoidis dominicensis (upper panels) showing the A. vertebral column; B. first dorsal vertebra; C. sacral rib complex. Comparative views of C. alburyorum (lower panels) showing the D. vertebral column; E. first dorsal vertebra; F. sacral rib complex.

FIGURE 7. Comparative views of the skulls of Chelonoidis dominicensis (left column) in A. dorsal view; C. lateral view; E. posterior view; and C. alburyorum (right column) B. dorsal view; D. lateral view; F. ventral posterior view. Separate scale bars represent 10 mm for each specimen.