The Evolution of Vertebral Number and Body Size in Snakes

A new species of Atractus (Serpentes: Dipsadidae) from Serra do Cipó, Espinhaço Range, Southeastern Brazil, with proposition of a new species group to the genus

“…We cannot establish if the only female represents an outlier, but its presents the high number of ventral scales which is usually correlated with snakes body size (see Lindell, 1994). Otherwise, A. spinalis will be the only congener exhibiting inverted sexual dimorphism (males longer than females), but this need to be confirmed by more representative samples.…”

Structurally Unique Inhibitors of Human Mitogen-Activated Protein Kinase Phosphatase-1 Identified in a Pyrrole Carboxamide Library

“…Phyletic body size increases are associated with increased somite numbers (pleomerism) in actinopterygian fish (Lindsey 1975), plethodontid salamanders ( Jockusch 1997) and derived colubroid snakes (Lindell 1994), but not in groups whose vertebral column is highly regionalized and functionally constrained like mammals and birds (Wake 1979), in which body size changes are a function of postembryonic somatic growth. Although pleomerism has been established as a mechanism of body size evolution in snakes, its role in the evolution of gigantism is unknown.…”

Ecomorfologia em serpentes neotropicais: um estudo de caso com a tribo Pseudoboini

“…iglesiasi and P. guianensis have many vertebrae per body unit, contradicting the hypothesis that semi-fossorial snakes tend to have fewer body vertebrae than species occupying other microhabitats (Lindell, 1994). However, inferences about the semi-fossorial habit of these two species (Rodrigues, 1993(Rodrigues, , 2003 are based upon only a few observations of individuals in the wild and thus this conclusion should be considered cautiously.…”

“…Constriction has been shown to be related with an increase in the number of body vertebrae in snakes, which may facilitate body bending (Jayne, 1982;Lindell, 1994), what could explain part of the variation of this trait among pseudoboines. Future studies using different snake lineages, in which the arboreal habit evolved independently many times, would help to elucidate the eventual effect of arboreality on the number of body vertebrae in snakes.…”

“…However, the number of ventral scales, which corresponds to the number of body vertebrae in many snake species, has been the focus of only a few studies concerning snake morphology and arboreality (e.g. Lindell, 1994;Pizzatto et al, 2007a) and remains poorly explored.…”