The enigmatic tetrapod Acherontiscus caledoniae from the Pendleian stage of the Early Carboniferous shows heterodontous and durophagous teeth, representing the earliest known examples of significant adaptations in tetrapod dental morphology. Tetrapods of the Late Devonian and Early Carboniferous (Mississippian), now known in some depth, are generally conservative in their dentition and body morphologies. Their teeth are simple and uniform, being cone-like and sometimes recurved at the tip. Modifications such as keels occur for the first...

Environmental heterogeneity shapes the uneven distribution of resources available to foragers, and is ubiquitous in nature. Optimal foraging theory predicts that an animal’s ability to exploit resource patches is key to foraging success. However, the potential fitness costs and benefits of foraging in a heterogeneous environment are difficult to measure empirically. Heterogeneity may provide higher quality foraging opportunities, or alternatively could increase the cost of resource acquisition because of reduced patch density or increased competition....

Data were collected in 2015, 2016 and 2017 to provide information on the distribution of flow depth and depth-averaged flow velocity at cross-sections on the South Saskatchewan River, Canada. Data were obtained using a Sontek M9 acoustic Doppler current profiler (aDcp) mounted onto either a small zodiac boat or a SonTek Hydroboard. Data for each cross-section is recorded in a single file. Individual points within each file represent single locations on the particular cross-section. Data...