Convergent Evolution in Aquatic Tetrapods: Insights from an Exceptional Fossil Mosasaur

Mosasaurs (family Mosasauridae) are a diverse group of secondarily aquatic lizards that radiated into marine environments during the Late Cretaceous (98–65 million years ago). For the most part, they have been considered to be simple anguilliform swimmers – i.e., their propulsive force was generated by means of lateral undulations incorporating the greater part of the body – with unremarkable, dorsoventrally narrow tails and long, lizard-like bodies. Convergence with the specialized fusiform body shape and inferred carangiform locomotory style (in which only a portion of the posterior body participates in the thrust-producing flexure) of ichthyosaurs and metriorhynchid crocodyliform reptiles, along with cetaceans, has so far only been recognized in Plotosaurus, the most highly derived member of the Mosasauridae. Here we report on an exceptionally complete specimen (LACM 128319) of the moderately derived genus Platecarpus that preserves soft tissues and anatomical details (e.g., large portions of integument, a partial body outline, putative skin color markings, a downturned tail, branching bronchial tubes, and probable visceral traces) to an extent that has never been seen previously in any mosasaur. Our study demonstrates that a streamlined body plan and crescent-shaped caudal fin were already well established in Platecarpus, a taxon that preceded Plotosaurus by 20 million years. These new data expand our understanding of convergent evolution among marine reptiles, and provide insights into their evolution's tempo and mode

Homeotic Evolution in the Mammalia: Diversification of Therian Axial Seriation and the Morphogenetic Basis of Human Origins

Despite the rising interest in homeotic genes, little has been known about the course and pattern of evolution of homeotic traits across the mammalian radiation. An array of emerging and diversifying homeotic gradients revealed by this study appear to generate new body plans and drive evolution at a large scale.This study identifies and evaluates a set of homeotic gradients across 250 extant and fossil mammalian species and their antecedents over a period of 220 million years. These traits are generally expressed as co-linear gradients along the body axis rather than as distinct segmental identities. Relative position or occurrence sequence vary independently and are subject to polarity reversal and mirroring. Five major gradient modification sets are identified: (1)--quantitative changes of primary segmental identity pattern that appeared at the origin of the tetrapods ; (2)--frame shift relation of costal and vertebral identity which diversifies from the time of amniote origins; (3)--duplication, mirroring, splitting and diversification of the neomorphic laminar process first commencing at the dawn of mammals; (4)--emergence of homologically variable lumbar lateral processes upon commencement of the radiation of therian mammals and ; (5)--inflexions and transpositions of the relative position of the horizontal septum of the body and the neuraxis at the emergence of various orders of therian mammals. Convergent functional changes under homeotic control include laminar articular engagement with septo-neural transposition and ventrally arrayed lumbar transverse process support systems.Clusters of homeotic transformations mark the emergence point of mammals in the Triassic and the radiation of therians in the Cretaceous. A cluster of homeotic changes in the Miocene hominoid Morotopithecus that are still seen in humans supports establishment of a new "hominiform" clade and suggests a homeotic origin for the human upright body plan

Brief acceptance-based intervention for increasing intake attendance at a community mental health center.

Intake no-show rates for psychotherapy vary from 20% to 57% (Swenson & Pekarik, 1988), and experiential avoidance may be related to failure to attend intake sessions. This pilot study attempted to increase intake attendance at a community mental health center by employing a brief experiential acceptance-based intervention. Those who scheduled intakes were randomly assigned to 1 of 2 groups: orientation letter or acceptance-enhanced orientation letter; rates from these conditions were compared with a retrospective comparison control group. Participants were randomized by way of an online random number generator. Persons assigned to the orientation group did not have a higher show rate than persons within the control group (̃48% compared with ̃52%). Persons assigned to the acceptance group did have higher show rates than persons in the other two groups (̃67% compared with ̃48% and ̃52%, respectively), however this difference was nonsignificant. Results suggest that brief acceptance-based interventions should be further studied for their potential value in maximizing client attendance. © 2014 American Psychological Association

Brief acceptance-based intervention for increasing intake attendance at a community mental health center

Intake no-show rates for psychotherapy vary from 20% to 57% (Swenson & Pekarik, 1988), and experiential avoidance may be related to failure to attend intake sessions. This pilot study attempted to increase intake attendance at a community mental health center by employing a brief experiential acceptance-based intervention. Those who scheduled intakes were randomly assigned to 1 of 2 groups: orientation letter or acceptance-enhanced orientation letter; rates from these conditions were compared with a retrospective comparison control group. Participants were randomized by way of an online random number generator. Persons assigned to the orientation group did not have a higher show rate than persons within the control group (̃48% compared with ̃52%). Persons assigned to the acceptance group did have higher show rates than persons in the other two groups (̃67% compared with ̃48% and ̃52%, respectively), however this difference was nonsignificant. Results suggest that brief acceptance-based interventions should be further studied for their potential value in maximizing client attendance. © 2014 American Psychological Association