Exploring ancestral phenotypes and evolutionary development of the mammalian middle ear based on Early Cretaceous Jehol mammals

We report a new Cretaceous multituberculate mammal with 3D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentially representing ancestral phenotypes of the mammalian middle ear. These phenotypes show that the ectotympanic and the malleus-incus complex changed notably during their retreating from the dentary at various evolutionary stages and suggest convergent evolution of some features to extant mammals. In contrast, the incudomalleolar joint was conservative in having a braced hinge configuration, which narrows the morphological gap between the quadroarticular jaw joint of non-mammalian cynodonts and the incudomalleolar articulations of extant mammals. The saddle-shaped and abutting malleus-incus complexes in therians and monotremes, respectively, could have evolved from the braced hinge joint independently. The evolutionary changes recorded in the Mesozoic mammals are largely consistent with the middle ear morphogenesis during the ontogeny of extant mammals, supporting the relation between evolution and development.     

Behavior ratings of emotionally disturbed children by teachers,parents, and school psychologists

Emotional disturbance was rated by teachers, parents, and the school psychologist for a group of 104 children diagnosed as severely emotionally disturbed. Teachers were found significantly more severe in their judgments than the school psychologist on the Behavior and Socialization scales of the Referral Checklist, but not on Communication. The teacher rating profile was also found to deviate from parallelness from the other raters with increased severity in the Behavior scale. None of the nine correlations between judges on the same scales was significant. Interpretations and possible implications are offered.