Norops

Abstract: We investigated whether forest-pasture edges affect the distribution of an assemblage of small vertebrate ectotherms in a consistent and predictable manner. We describe the abundance and distribution of two species of anoline lizards ( Norops) and five species of leaf-litter frogs ( Eleutherodactylus) along the edges and in the interiors of nine forest fragments near Las Cruces, Costa Rica. Over 4 months, we surveyed 44 pairs of plots by visual encounter. In each pair of plots, one was immediately adjacent to the pasture and the second was within the forest “interior.” Both plots of a pair were searched simultaneously. This block design controlled for the effects of weather, topography, and searcher ability. The distribution of all species was highly variable with respect to edges. Only two species of frogs, Eleutherodactylus podiciferus and E. cruentus, were significantly more abundant in interior plots than in edge plots, although not consistently so. Both species of Norops lizards were more abundant along forest edges during the dry season. Both Norops species and several Eleutherodactylus species, however, appeared to become more abundant in the forest interior after the onset of the wet season, suggesting a seasonal edge effect. In Norops polylepis, the most abundant anole, rates of ectoparasitism were lower along edges than in forest interiors. The magnitude of the edge effect on any one species was not influenced by the size of fragments or by the distance of the interior plot from the nearest edge. We believe that edge effects should not be defined by the distance to which they are detected. Rather, they should be viewed as highly dynamic in space and time; taxa appear to respond to different components of edge effects according to their particular biological requirements.

Abstract: -Relationships among lizards of the anole genera Chamaeleolis, Chamaelinorops, Phenacosaurus, and Anolis (sens,u lato) are discussed based upon a cladistic analysis of osteological, karyological, and albumin immunological data. Osteological data support a sister-group relationship of carolinensis subsection and beta section anoles, while anoles of the bimaculatus-cristatellus-cybotes, cuvieri series, and latifrons series are sequentially more distantly related to this terminal cluster. Karyological data support five major groupings. One of these groups represents those forms with the primitive karyotype for lizards and includes: Chamaeleolis, Chamaelinorops, and Phenacosaurus; the cuvieri, cybotes, and latifrons series; and most of the carolinensis subsection. Two groups with advanced karyotypes characterize the cristatellus and bimaculatus series, respectively. The remaining two groups of karyotypes characterize the beta subsection. One population of beta anoles possesses the modal karyotype of both of these groups suggesting a saltatorial evolution of chromosomes within anoles and making difficult the determination of relations among the five groupings of karyotypes. Albumin immunological data support a close sister-group relationship among the beta section, and the cristatellus and bimaculatus series, while the carolinensis series and latifrons series are sequentially more distantly related. Within Anolis (sensu lato), five distinct monophyletic lineages are recognized as genera. The latifrons series (placed in the genus Dactyloa) is derived relative to the primitive anole genera in the presence of autotomic septa on the caudal vertebrae and reduced numbers of aseptate caudal vertebrae. The cuvieri series (placed in Semiurus) shares with other advanced anoles the derived conditions for the shape of the parietal, parietal cresting, total number of parasternal ribs, and number of attached parasternal ribs, but lacks the derived condition of occipital region of more advanced anoles. The bimaculatus-cristatellus-cybotes series (placed in Ctenonotus) represents a lineage possessing a derived condition of the occipital region and a derived total number of parasternal ribs but lacks the derived shape of the interclavicle. The most derived lineagesthe carolinensis subsection and beta section-are linked by the derived shape of the interclavicle. The carolinensis subsection is diagnosed by derived numbers of lumbar vertebrae and constitutes the genus Anolis. The beta section is diagnosed by derived processes on the caudal vertebrae and is placed in the genus Norops. This systematic arrangement eliminates the paraphyletic nature of the alpha section and punctatus subsection. Although some aspects of current distribution patterns of anoles must be due to dispersal events, it appears that vicariant events provided the impetus for the separation of the anole genera into their current ranges. On the basis of a cladogram of areas and recent geological evidence of vicariant and accretional events in the Caribbean, it seems that a widespread ancestral distribution of anoles throughout Central and South America, connected by a protoGreater Antilles bridge, was fragmented by geological events forcing part of the proto-Greater Antilles northeastward towards their present location. This fragmented the distribution of primitive anoles in South America (Phenacosaurus and Dactyloa), and on Hispaniola and Cuba (Chamaelinorops and Chamaeleolis, respectively) from the ancestors of the advanced forms on Central America and associated portions of the rest of the proto-Greater Antilles. More advanced anole genera were added to the Caribbean by additional geological activity which separated the remainder of the proto-Greater Antilles into a Hispaniolan-Puerto Rican block and a CubanHispaniolan block. Separation and accretion of these blocks brought Semiurus, Ctenonotus, and Anolis to their present distributions, leaving Norops on Central America as well as on an attached block that later separated to become Jamaica. The closing of the Panamanian portal allowed extensive invasion of South America by Norops and less extensive invasion of Central America by Dactyloa. [Anolis; Iguanidae; cladistic; biogeography; Caribbean; osteology; karyology; immunology.] The iguanid lizard genus Anolis (sensu lato), among the most diverse (approximately 250 recognized species) vertebrate genera, continues to challenge attempts by systematic herpetologists to analyze its phylogeny. In spite of the pioneering ef-