Body form is one of the major consequences of development, and diversification of body shapes implies developmental changes among species. In anurans, changes in the timing of developmental events or heterochrony, have been emphasized as a source of variation in the patterns of development that has lead to diverse morphology. Herein, different approaches are used to explore morphological traits in members of the Ceratophryinae (Anura: Leptodactylidae), a group of frogs with some features produced by overdevelopment. Cladistic analyses were conducted in order to distinguish the shared history of Ceratophrys, Chacophrys and Lepidobatrachus and other anurans. From these studies, morphological variation of selected skeletal features in ceratophryines reveals the presence of ancient structures, which have been considered lost in the neobatrachian phylogeny, integrated in particular designs. Thin-plate spline morphometric analyses of skull shapes among ceratophryines describe Lepidobatrachus as the most distinctive shape. Moreover, thin-plate spline morphometric analyses among anurans show divergent skull shapes between ceratophryines and other anurans, reflecting that the skull shapes of ceratophryines are a result of peramorphosis (increase of developmental rates). This study represents the first detailed examination of the role of peramorphosis in a clade of anurans.

Shubin and Alberch (Evol Biol 1986;20:319-387) proposed a scheme of tetrapod limb development based on cartilage morphogenesis that provides the arguments to interpret the homologies of skeletal elements and sets the basis to explain limb specialization through later developmental modification. Morphogenetic evidence emerged from the study of some reptiles, but the availability of data for lizards is limited. Here, the study of adult skeletal variation in 41 lizard taxa and ontogeny in species of Liolaemus and Tupinambis attempts to fill in this gap and provides supporting evidence for the Shubin-Alberch scheme. Six questions are explored. Is there an intermedium in the carpus? Are there two centralia in the carpus? Is there homology among proximal tarsalia of reptiles? Does digit V belong to the digital arch? Is the pisiform an element of the autopodium plan? And should the ossification processes be similar to cartilage morphogenesis? We found the following answers. Some taxa exhibit an ossified element that could represent an intermedium. There is one centrale in the carpus. Development of proximal tarsalia seems to be equivalent with that observed among reptiles. Digit V could arise from the digital arch. Pisiform does not arise as part of the limb plan. And different patterns of ossification occur following a single and conservative cartilaginous configuration. Lizard limb development shows an early pattern common to other reptiles with clear primary axis and digital arch. The pattern then becomes lizard-specific with specialization involving some reduction in prechondrogenic elements. Anat Rec 290: 900-912, 2007. 2007 Wiley-Liss, Inc.Key words: limb; morphogenesis; lizards; homology Shubin and Alberch (1986) reviewed the literature on the development and evolution of the tetrapod limb and proposed a formalism to describe limb skeleton based on the spatial connectivities among cartilaginous condensations during earlier stages of limb morphogenesis (Fig. 1). This proposal allowed comparisons among tetrapod taxa and provided a conceptual basis to interpret the homologies of the skeletal components of the tetrapod limbs. From this approach, several paleontological, embryological, and developmental genetic studies have contributed with important data to explain the evolution and diversification of vertebrate locomotor appendages and have established the homologies of their components.The interspecific variation of limb skeleton in lizards has been explored by different authors with different

Heterochrony produces morphological change with effects in shape, size, and/or timing of developmental events of a trait related to an ancestral ontogeny. This paper analyzes heterochrony during the ontogeny of Ceratophryinae (Ceratophrys, Chacophrys, and Lepidobatrachus), a monophyletic group of South American frogs with larval development, and uses different approaches to explore their morphological evolution: (1) inferences of ancestral ontogenies and heterochronic variation from a cladistic analysis based on 102 morphological larval and adult characters recorded in ten anuran taxa; (2) comparisons of size, morphological variation, and timing (age) of developmental events based on a study of ontogenetic series of ceratophryines, Telmatobius atacamensis, and Pseudis platensis. We found Chacophrys as the basal taxon. Ceratophrys and Lepidobatrachus share most derived larval features resulting from heterochrony. Ceratophryines share high rates of larval development, but differ in rates of postmetamorphic growth. The ontogeny of Lepidobatrachus exhibits peramorphic traits produced by the early onset of metamorphic transformations that are integrated in an unusual larval morphology. This study represents an integrative examination of shape, size, and age variation, and discusses evolutionary patterns of metamorphosis.