Pectoral and pelvic girdle rotations play a substantial role in enhancing stride length across diverse tetrapod lineages. However, the pectoral and pelvic girdle attach the limbs to the body in different ways and may exhibit dissimilar functions,…
All mammals must breathe and breathe continuously from birth. Similarly, all mammals, including infants, have high functional demands for feeding. However, the pathway that food takes through the pharynx interrupts respiration. The coordination…
The distribution and performance of aquatic vertebrates can be linked strongly to their ability to perform in variable conditions of flowing water. Performance in these variable conditions can be affected by both morphology and behaviour, and animals…
BACKGROUND: The formation of a bolus of food is critical for proper feeding function, and there is substantial variation in the size and shape of a bolus prior to a swallow. Preterm infants exhibit decreased abilities to acquire and process food, but…
Wild primates encounter complex matrices of substrates that differ in size, orientation, height, and compliance, and often move on multiple, discontinuous substrates within a single bout of locomotion. Our current understanding of primate gait is…
The medial geniculate body (MG) receives a large input from the ipsilateral inferior colliculus (IC) and a smaller but substantial input from the contralateral IC. Both crossed and uncrossed inputs comprise a large percentage of glutamatergic cells…
The medial geniculate body (MG) receives a large input from the ipsilateral inferior colliculus (IC) and a smaller but substantial input from the contralateral IC. Both crossed and uncrossed inputs comprise a large percentage of glutamatergic cells…
The pineal gland is a naturally calcifying endocrine organ which secretes the sleep-promoting hormone melatonin. Age-related changes of the pineal have been observed, including decreased pinealocyte numbers, increased calcification, and a reduction…
Previous descriptive work on deciduous dentition of primates has focused disproportionately on great apes and humans. To address this bias in the literature, we studied 131 subadult nonhominoid specimens (including 110 newborns) describing deciduous…
Few studies exist of the bowhead whale brain and virtually nothing is known about its cortical cytoarchitecture or how it compares to other cetaceans. Bowhead whales are one of the least encephalized cetaceans and occupy a basal phylogenetic position…
The external auditory meatus (EAM) in many species of mysticete whales is filled with a waxy ear plug. Though this lamellated structure is often used to age a whale, its formation and development remain undescribed. It is thought that growth layer…
The external acoustic meatus (EAM) of most baleen whales accumulates cellular debris annually in the lumen as whales age, forming a lamellated ear plug. The bowhead whale ear plug is formed from annually molting lining of the EAM as the entire…
Age-related hearing loss may result, in part, from declining levels of gamma-amino butyric acid (GABA) in the aging inferior colliculus (IC). An upregulation of the GABA(A)R gamma(1) subunit, which has been shown to increase sensitivity to GABA,…
Age-related hearing loss may result, in part, from declining levels of γ-amino butyric acid (GABA) in the aging inferior colliculus (IC). An upregulation of the GABAAR γ1 subunit, which has been shown to increase sensitivity to GABA, occurs in the…
Studying ontogeny in both extant and extinct species can unravel the mechanisms underlying mammal diversification and specialization. Among mammalian clades, Cetartiodactyla encompass species with a wide range of adaptations, and ontogenetic evidence…
The inferior colliculus occupies a central position in ascending and descending auditory pathways. A substantial proportion of its neurons are GABAergic, and these neurons contribute to intracollicular circuits as well as to extrinsic projections to…
Several bony and soft tissue structures of the callitrichid masticatory apparatus have been studied to understand how gouging behavior in marmosets is facilitated by specific morphologies. While marmoset craniofacial anatomy indicates features that…
OBJECTIVE: Determine sarcomere length (Ls) operating ranges of the superficial masseter and temporalis in vitro in a macaque model and examine the impact of position-dependent variation on Ls and architectural estimates of muscle function (i.e.,…
Dental microwear analysis has been employed in studies of a wide range of modern and fossil animals, yielding many insights into the biology/ecology of those taxa. Paleoanthropological studies have produced both expected and unexpected results (e.g.,…
The lab and field provide differing approaches to studying primate biology. We outline the challenges and benefits of these approaches and demonstrate how collaboration can help bridge these perspectives to provide complementary insight into primate…
Feeding and diet played key roles in human evolution. It is well known that modern humans have a small masticatory apparatus for their body size among primates. However, identifying gracility does not necessarily tell us about the relative functional…
The influence of substrate compliance on gait mechanics has received little attention in previous studies of primate locomotion. Using high-speed video, we investigated how free-ranging platyrrhines in lowland Amazonian Ecuador adjust gait kinematics…
