The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of i...

THE skins of many vertebrates react to variations in the amount of hormones of the endocrine glands, especially of the thyroid and pituitary. Moulting in Triturus viridescens is inhibited after both thyroidectomy and hypophysectomy or both operations simultaneously performed. The cornified layers continue to form and the accumulation of these makes the animal appear grimy (Adams and Richards, 1...

A systematic understanding of traffic dynamics on road networks is crucial for many transportation studies and can help to develop more efficient ramp metering, evacuation, signal control, and other management and control strategies. In this study, we present a theory of multi-commodity network traffic flow based on the Lighthill–Whitham–Richards (LWR) model. In particular, we attempt to analyz...