Name: Patricia Palmeira Bellon
Type: MSc dissertation
Publication date: 04/06/2021
Advisor:
Name |
Role |
|---|---|
| Sérgio Lucena Mendes | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Bárbara Maria de Andrade Costa | External Alternate * |
| Elisandra de Almeida Chiquito | Co advisor * |
| Karen Barbara Strier | Internal Examiner * |
| Sérgio Lucena Mendes | Advisor * |
| William Corrêa Tavares | External Examiner * |
| Yuri Luiz Reis Leite | Internal Alternate * |
Summary: The cranial morphology of Alouatta (Howler Monkey) is unique among Platyrrhini primates,
due to the dorsoventral rotation of the face in relation to the neurocranium, a condition called
airorhynchy. Howler Monkeys has positive sexual dimorphism, males have a larger body
size than females. However, not much is known about sexual dimorphism related to the cranium
dimensions and age variation. Between the end of 2016 and mid-2017 one of the most severe
outbreaks of yellow fever affected Brazil. This outbreak affected mainly the states of Minas
Gerais and Espírito Santo, causing one of the largest non-human primates deaths that science
has already recorded, the Brown Howler Monkeys being the most affected. This study analyzed
155 specimens of Alouatta, guariba, which were prepared and deposited at the Instituto
Nacional da Mata Altântica (INMA). The objective of this work was to analysis the cranial
morphometric variation for the specie and an realize in-depth study on ontogenetic variation
and sexual dimorphism of A. guariba, in addition to characterizing the demographic profile of
Brown Howler Monkeys in sex and age groups and mapping the samples collected. Data
analysis indicates that adult males were the most collected group during the yellow fever
outbreak. The samples come from 116 locations, mainly distributed in the southern portion of
Espírito Santo, in the mountain region. Sexual dimorphism in howler monkeys is present in
most cranial variables before the adult age. The morpho-functional regions that showed sexual
dimorphism from the sub-adult age group were: hyoid, jaw, oral, nasal and zygomatic. In
contrast, the morpho-functional regions that did not present sexual dimorphism were: cranial
vault, cranial base and orbit. It was possible to identify sexual dimorphism in the cranial
variables regardless of the presence of the hyoid bone.
Keywords: Morphometry. Sexual Dimorphism. Primates. Yellow Fever.
