Ronaldo Fernandes

Revision of the Epicrates cenchria Complex (Serpentes: Boidae)

Abstract The Epicrates cenchria complex is endemic to the Neotropical region, occurring in mainland portions of Central and South America. The taxonomic status of the nine currently recognized subspecies (E. c. alvarezi, E. c. assisi, E. c. barbouri, E. c. cenchria, E. c. crassus, E. c. gaigei, E. c. hygrophilus, E. c. maurus, and E. c. polylepis), were evaluated based on external morphology, osteology, and hemipenis characters. Results obtained through quantitative and qualitative analyses support the recognition of E. alvarezi, E. assisi, E. cenchria, E. crassus, and E. maurus as distinct species based on statistically robust delimitation of species boundaries.

A NEW SPECIES OF ATRACTUS (SERPENTES: COLUBRIDAE) FROM SOUTHERN BRAZIL

A new species of Atractus is described from grasslands of the State of Rio Grande do Sul, southern Brazil. The new species is distinguished from all congeners by the combination of a single postocular, long loreal, six supralabials, generally six infralabials, 17 dorsal scales rows, six or seven maxillary teeth, and a dorsal color pattern in preservative uniformly grayish-brown with a creamish-white temporal region. Comparisons of the new species are made with all other Atractus species, and its affinities with A. reticulatus and allied species are suggested based on the morphology of the hemipenis.

BITE MARKS ON A CROCODYLOMORPH FROM THE UPPER CRETACEOUS OF BRAZIL: EVIDENCE OF SOCIAL BEHAVIOR?

Fossil bones that bear marks from activities of other organisms can provide insight into the ecology, behavior, and functional morphology of the taxa that produced them (Evans, 1983; Bell and Martin, 1995; Erickson and Olson, 1996; Tanke and Currie, 1998). However, most studies on such marks concern invertebrate bioturbation or bioerosion (Carvalho and Fernandes, 2000). Studies on bone marks produced by vertebrates are less common (Abel, 1922; Buffetaut, 1983; Evans, 1983; Fiorillo, 1991; Erickson and Olson, 1996; Tanke and Currie, 1998; Frey et al., 2002). Bite marks are usually interpreted as the result of predator or scavenger habit, although determination between these two habits is controversial, at best. In other words, it is uncertain if the teeth marks presented on a fossil are record of the use of a lethal “weapon” or the record of a post-mortem alimentary association. In the austral spring of 2001, the Laboratório de Macrofósseis/IGEO Universidade Federal do Rio de Janeiro organized a paleontological expedition to some fossil localities at the Adamatina Formation in the state of São Paulo. The Adamantina Formation is a very fossiliferous unit of the Bauru Basin, Brazil. The most important fossil localities of this basin are located in the states of São Paulo, Mato Grosso, and Minas Gerais (Kellner and Campos, 2000), where a rich fauna of fishes, amphibians, crocodiles, lizards, turtles, dinosaurs and a mammal have been recovered (Bertini et al., 1993). The Adamantina Formation is dominated by reddish clays and sands of fluvial-lacustrine origin, deposited during times of warm and humid climates (Suguio and Barcelos, 1983). Judging from its vertebrate fossil contents, the Adamantina deposits were likely deposited sometime between the Santonian and Maastrichtian (Fernandes and Coimbra, 1996). The 2001 expedition produced a collection of ichnofossils and fossil remains including, mollusks, fishes, turtles, crocodylomorphs, and dinosaurs. Among these fossils, we found a tail of an adult crocodylomorph (Fig. 1) on which we found evidence of bite injuries. In the present paper, we describe those marks and argue that members of the same species made those injuries, probably in intermale combat.

Three New Atractus (Serpentes: Dipsadidae) from the Andes of Colombia

Abstract Three new species of Atractus are described from the northern Cordillera Central of Colombia. The new species, previously confused with older names, are easily distinguished from any currently recognized Atractus by unique combinations of morphological characters. Additionally, we provide comments on the Atractus diversity and distribution pattern in the Colombian Andes.

Morphology and diet of two sympatric colubrid snakes, Chironius flavolineatus and Chironius quadricarinatus (Serpentes: Colubridae)

The morphometry and diet of two sympatric species of Chironius (C. flavolineatus and C. quadricarinatus) from Brazilian Cerrado are described. The two snake species differ in external morphology, as Chironius flavolineatus was the largest species (body, tail and eyes) whereas C. quadricarinatus the heaviest. Each species also showed marked sexual size dimorphism. In terms of dietary ecology, both species feed exclusively on frogs with a heavy preference for hylids and may have tendency to eat small items, as noticed in other colubrine species. These two snake species showed a brownish colour pattern and exhibited no ontogenetic variation, suggesting that juveniles and adults use similar substrates. Chironius flavolineatus and C. quadricarinatus present a semi-arboreal habit, with active foraging behaviour, feeding in the ground most of time. Chironius flavolineatus uses higher vegetation for resting and, based on morphological results, seems to be more arboreal than C. quadricarinatus.

A New Blind Snake Species of the Genus Tricheilostoma from Espinhaço Range, Brazil and Taxonomic Status of Rena dimidiata (Jan, 1861) (Serpentes: Epictinae: Leptotyphlopidae)

Designation and description of a neotype and geographic variation of the blind snake Rena dimidiata are presented here on the basis of a noted sample, providing a question on its generic identity, and proposing a new taxonomic combination. Rena dimidiata is recognized here as a species of Tricheilostoma, based on putative characters published in a recent paper, additional external traits and hemipenial characters. Morphometric and meristic characters for all species of Tricheilostoma are described herein. Additionally, a new species of Tricheilostoma is described from Espinhaço Range, Brazil.

Reproductive biology of two sympatric colubrid snakes, Chironius flavolineatus and Chironius quadricarinatus, from the Brazilian Cerrado domain

The reproductive biology of Chironius flavolineatus and C. quadricarinatus from the Brazilian Cerrado domain is described, including sexual maturity, female fecundity, and reproductive cycles of males and females. Egg-laying is recorded here for the first time for C. quadricarinatus. Males of both species attain sexual maturity with a smaller snout-vent length than females. Females of C. flavolineatus have an extended reproductive cycle with egg production during the wet season, whereas males exhibit year-round sperm production. Chironius quadricarinatus has continuous reproductive cycles in both sexes. Differences in reproductive pattern between these two sympatric species are probably related to phylogenetic constraints on intrageneric lineages of Chironius.

Reproductive Biology and Notes on Natural History of the Side-necked Turtle Acanthochelys radiolata (Mikan, 1820) in Captivity (Testudines: Chelidae)

Abstract Sixteen adult specimens (six males and ten females) of Acantochelys radiolata from different regions of the state of Rio de Janeiro, Brazil, were monitored in captivity from 1996 to 2000 in order to obtain data on species reproductive biology including breeding season, egg laying, egg incubation, and hatchlings. Mating behaviour was observed between November and March and showed a regular pattern constituted by three conspicuous phases: approximation, persecution, and copulation. Sixteen clutches were found between March and July and twelve eggs were found in natural conditions. Hatches occurred between September and November. Hatchlings showed gular region, anterior and posterior members, tail, and edges of carapace and plastron with reddish blotches resting on a black background. This pattern was modified to an orange tonality in the third month of life.

Morphological variation of Trilepida macrolepis (Peters 1857), with reappraisal of the taxonomic status of Rena affinis (Boulenger 1884) (Serpentes: Leptotyphlopidae: Epictinae)

We report on the morphological variation (meristic, morphometric, pholidosis, and color pattern characters) and sexual dimorphism of Trilepida macrolepis. We also took the opportunity to redescribe the holotype of Rena affinis in an effort to evaluate its taxonomic status. Based on the congruence of characters from external morphology, we transfer Stenostoma affine to the genus Trilepida. We also discuss the Andean specimens previously refereed to Trilepida affinis and Trilepida macrolepis and provide an identification key for the genus Trilepida.