Most Neotropical birds, including Pteroglossus aracaris, do not have an adequate fossil record to be used as time constraints in molecular dating. Hence, the evolutionary timeframe of the avian biota can only be inferred using alternative time constraints. We applied a Bayesian relaxed clock approach to propose an alternative interpretation for the historical biogeography of Pteroglossus based on mitochondrial DNA sequences, using different combinations of outgroups and time constraints obtained from outgroup fossils, vicariant barriers and molecular time estimates. The results indicated that outgroup choice has little effect on the Bayesian posterior distribution of divergence times within Pteroglossus , that geological and molecular time constraints seem equally suitable to estimate the Bayesian posterior distribution of divergence times for Pteroglossus , and that the fossil record alone overestimates divergence times within the fossil-lacking ingroup. The Bayesian estimates of divergence times suggest that the radiation of Pteroglossus occurred from the Late Miocene to the Pliocene (three times older than estimated by the “standard” mitochondrial rate of 2% sequence divergence per million years), likely triggered by Andean uplift, multiple episodes of marine transgressions in South America, and formation of present-day river basins. The time estimates are in agreement with other Neotropical taxa with similar geographic distributions.

Partial cytochrome b and 12S rDNA mitochondrial DNA sequences of eight representatives of the Ramphastidae family were analyzed. We applied the linearized tree method to identify sequences evolving at similar rates and estimated the divergence times among some of the taxa analyzed. After excluding Ramphastos tucanus and Capito dayi from our data set, the remaining taxa presented a constant rate of DNA substitution, and branch lengths could be re-estimated with a clock constraint using the maximum likelihood method. Branch lengths were calibrated assuming that Galliformes and Piciformes split around 100 million years ago (mya). Our results indicate that Ramphastinae, and probably Capitoninae, diverged from other Piciformes in the Late Cretaceous (~82 mya), suggesting that Piciformes is another avian order that survived the mass extinction event occurred 65 mya at the Cretaceous/Tertiary (K/T) boundary. The divergence times estimated within the Ramphastinae genera cover the period from the Middle Eocene (around 47 mya) through the Late Miocene (9.5 mya). Our estimate of divergence time is coincidental with the split of the African and the South American continents and other intense geologic activities and modifications of the areas which correspond to the current Neotropics. These events might have influenced the diversification of Ramphastinae in South America.

Crianças com síndrome de Sotos apresentam aceleração do crescimento, macrocrania, padrões acromagalóides e dificuldades iniciais no desenvolvimento neuropsicomotor. A delineação da síndrome e o diagnóstico diferencial estão baseados na avaliação das características clínicas e no histórico evolutivo desses pacientes. Sete pacientes com síndrome de Sotos são descritos, bem como revistas as características clínicas presentes em 198 pacientes da literatura. As dificuldades motoras presentes durante a primeira infância nos pacientes com síndrome de Sotos são responsáveis pelo mau desempenho destas crianças nos testes de QI. A estimulação especializada deve ser encorajada para ajustar os afetados a superarem suas dificuldades iniciais.

Children with Sotos syndrome have growth acceleration, macrocephaly, acromegaloid features and delay in neuropsychomotor development during infancy. Syndrome delineation and differential diagnosis are based on evaluation of phenotypic characteristics and evolutive history of the patients. Seven patients with this syndrome are reported, and the relative occurrence of the phenotypic characteristics present in 198 reported cases are reviewed. Motor difficulties present in those patients during early infancy are responsible for the poor performance on IQ tests. Oriented stimulation should be encouraged in order to help the affected children to overcome their initial difficulties and to achieve normal scholarity and life performance.

É relatado o caso de uma paciente com síndrome de Pyle (displasia crâniometafisária), com sintomatologia de involução neuropsíquica, progressiva e sinais pirâmido-extrapiramidais. O estudo do cariótipo revelou a presença, em 12% das células, de fragmentação cromossômica, embora a análise da genealogia do propósito revelasse tratar-se de provável moléstia recessiva. São discutidas as hipóteses dos mecanismos da fragmentação cromossômica em tais eventualidades (moléstias recessivas), concluindo-se por provável fragmentação secundária no caso em questão.

The clinical and karyotypic analysis of a 7 years old girl with Pyle's disease are reported. Clinically the patient presented an unusual neuropsychic involution and pyramido-extrapyramidal symptomatology. The karyotypic analysis showed chromosomal breakage em 12% of the cells. However the genealogical study of the patient pointed towards a recessive disease. Various hypothesis of chromosomal breakage in recessive diseases are discussed, the possibility of secondary breakage being emphasized.