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Evolutionary radiations generate most of Earth’s biodiversity, but are there common ecomorphological traits among the progenitors of radiations? In Synapsida (the mammalian total group), ‘small-bodied faunivore’ has been hypothesized as the ancestral state of most major radiating clades, but this has not been quantitatively assessed across multiple radiations. To examine macroevolutionary patterns in a phylogenetic context, we generated a time-calibrated metaphylogeny (‘metatree’) comprising 1,888 synapsid species from the Carboniferous through the Eocene (305–34 Ma) based on 269 published character matrices. We used comparative methods to investigate body size and dietary evolution during successive synapsid radiations. Faunivory is the ancestral dietary regime of each major synapsid radiation, but relatively small body size is only established as the common ancestral state of radiations near the origin of Mammaliaformes in the Late Triassic. The faunivorous ancestors of synapsid radiations typically have numerous novel characters compared with their contemporaries, and these derived traits may have helped them to survive faunal turnover events and subsequently radiate. Small-bodied faunivory has been proposed as the ancestral condition of most major synapsid clades, but here using a time-calibrated metatree of 1,888 fossil synapsids, the authors show that while faunivory is commonly ancestral, small body size in radiation forerunners is a relatively late innovation, arising in the Late Triassic.

Expertise in the broader impacts of scientific research is an increasingly important aspect of professional development, particularly because federal grant proposals are commonly reviewed using both the Intellectual Merit and the Broader Impacts Criteria. Unfortunately, training in broader impacts, such as science communication and outreach, is not typically part of undergraduate or graduate curricula. We initiated one of the first graduate-level biology courses on broader impacts, focusing on giving graduate students firsthand, authentic experiences with grant writing, science communication, and educational outreach. Students in this interdisciplinary course learned from experts, wrote for a broad audience about their own research, and proposed and implemented outreach in collaboration with local organizations. We outline our approach, discuss outcomes from each activity, assess our impact, and finally consider how future programs might expand on this model.

Natural selection has produced a spectacular array of anatomical forms that are adapted to a wide range of environments. However, genetic, developmental, and functional factors may integrate an organism’s traits so that selection cannot optimize them independently for a given environment. A tension therefore exists between processes that promote anatomical diversification and those that promote integration. Using geometric morphometric, I how patterns of integration translate to morphological diversity in two important evolutionary transitions: the limb bones involved in the origin of birds from theropod dinosaurs and the dorsal heads of scarab beetles. My results show that integration of the fore- and hind limbs in theropod dinosaurs changed in the transition to flight. The results also indicate that developmental changes were associated with the change in integration and have been inherited by all birds, regardless of whether they retain the ability to fly. This may explain why flightless birds, despite evolving flightlessness independently, have similar forelimb characteristics. Integration patterns in scarab beetle heads support the hypothesis that ancestrally hornless species had a different modular composition than species in which only one sex has horns. Furthermore, different male morphs have different integration patterns, which supports the hypothesis that an identical complement of genes can also produce different phenotypic integration patterns via different developmental processes. Finally, male and female sexually dimorphic beetles have different integration patterns, suggesting that the sexes have independent genetic and developmental control of their head horns. Overall, I found that specific drivers of evolutionary integration can be identified in both modern and fossil taxa using geometric morphometric methods, even when multiple factors contribute to the pattern of integration. I also found that essentially identical complements of genes can result in different integration patterns. Finally, I found that although evolutionary changes in morphology and function can be accompanied by changes in trait integration, shared, conserved, developmental processes can mask the effects of functional influences on integration resulting in shared patterns of integration.

The vertebrate assemblage of the lower Fremouw Formation has been studied for nearly 50 years, but many components remain poorly known. We describe a partial presacral vertebra and the distal end of a left humerus collected just above the Permian—Triassic boundary in the Shackleton Glacier region of the central Transantarctic Mountains. Our identification of these specimens as archosauromorphs that represent at least one taxon of large-bodied archosauriform increases the known reptile diversity of the Fremouw Formation considerably, and provides the first definitive evidence for the presence of Archosauriformes in the Early Triassic of Antarctica. These records increase faunal similarities between the lower Fremouw Formation and other Early Triassic assemblages. Although the lower Fremouw assemblage is typically considered a subset of the coeval Lystrosaurus Assemblage Zone (LAZ) of South Africa, the discrepancy in inferred body size between the Antarctic specimens and Proterosuchus fergusi, coupled with the fact that the LAZ of the Karoo Basin has been sampled much more thoroughly, suggests a real disparity in the maximum body size of apex carnivores between the lower Fremouw assemblage and the LAZ. The lower Fremouw specimens also demonstrate that one or more lineages of archosauriform had attained the large body size characteristic of later members of the clade very soon after the end-Permian mass extinction. This offers a point of contrast with the global pattern of post-extinction terrestrial communities, which are typified by a marked reduction in body size (the ‘Lilliput effect’).