The horned dinosaur Pachyhinosaurus possesses rugose bony bosses across the skull roof in lieu of the projecting bony horn cores seen in most ceratopsians. This elaboration of typical ceratopsian ornaments provides an opportunity to test hypotheses…
We studied the ontogeny of muscarinic depression in the developing rat visual cortex using carbachol (a nonhydrolyzable cholinergic agonist) application to neocortical slices obtained from four postnatal age groups: 9-10 days, 15 days, 30-40 days and…
Arboreal mammals face unique challenges to locomotor stability. This is particularly true with respect to juveniles, who must navigate substrates similar to those traversed by adults, despite a reduced body size and neuromuscular immaturity.…
Physical anthropologists have devoted considerable attention to the structure and function of the primate prehensile tail. Nevertheless, previous morphological studies have concentrated solely on adults, despite behavioral evidence that among many…
Due to small body size, an immature musculoskeletal system, and other growth-related limits on performance, juvenile mammals frequently experience a greater risk of predation than their adult counterparts. As a result, behaviorally precocious…
Nearly all living artiodactyls (even-toed ungulates) possess a derived cranial arterial pattern that is highly distinctive from most other mammals. Foremost among a suite of atypical arterial configurations is the functional and anatomical…
In utero, baleen whales initiate the development of several dozens of teeth in upper and lower jaws. These tooth germs reach the bell stage and are sometimes mineralized, but toward the end of prenatal life they are resorbed and no trace remains…
Functional studies of skeletal anatomy are predicated on the fundamental assumption that form will follow function. For instance, previous studies have shown that the femora of specialized leaping primates are more robust than those of more…
The nasolacrimal duct (NLD) connects the orbital (often associated with the Deep Anterior Orbital gland: DAOG, a.k.a. Harderian gland) and nasal regions in many tetrapods. Adult cetaceans are usually said to lack an NLD, and there is little agreement…
Cetacean evolution was shaped by an extraordinary land-to-sea transition in which the ancestors of whales became fully aquatic. As part of this transition, these mammals evolved unusually thick blubber which acts as a metabolic reservoir as well as…