Population structure of the gomphothere Stegomastodon waringi (Mammalia: Proboscidea: Gomphotheriidae) from the Pleistocene of Brazil.
An Acad Bras Cienc
; 82(4): 983-96, 2010 Dec.
Article
em En
| MEDLINE
| ID: mdl-21152772
The Quaternary fossil record of Águas de Araxá (Q AA) is represented mainly by an accumulation of skeletal elements of several sizes, which are assigned to a population of Stegomastodon waringi. We analyzed 97 molars according to the ear stages of Simpson and Paula-Couto (1957), and developed a morphometric ear index. The population structure (proportion of immature, subadult, adult, mature adult and senile adult individuals) was identified, and these five age classes were compared to those of extant elephant populations and defined with social implications. The analysis made possible to establish that the population is largely composed of adults: 14.89% are immature individuals, 23.04% subadults, 27.65% adults, 17.21% mature adults and another 17.21% senile adults. Based on population structure, we do not discard the possibility that the fossil population was stable or in recovery, and/or was experiencing a high-predation period on younger individuals. The number of individuals composing the past population studied here could suggest that the occupied environment was open due to comparisons to populations of extant elephants. We consider this population as an aggregation of family units, which suggests a time of low environmental humidity. Based on literature and our findings, their extinction appears to be regional and probably related to a catastrophic event.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dente
/
Elefantes
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Mastodontes
/
Fósseis
Tipo de estudo:
Prognostic_studies
Limite:
Animals
País/Região como assunto:
America do sul
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Brasil
Idioma:
En
Revista:
An Acad Bras Cienc
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil