Craniometrical differentiation of gray brocket deer species from Brazil

Abstract

The genus Mazama Rafinesque, 1817 represent a successful adaptive radiation of South American deers, that has a wide distributional range in the Neotropical region, extending from the State of Vera Cruz in Mexico to central Argentina (from sea-level to 4,900 m a.s.l.; see Allen, 1915;Black-Decima et al., 2010;. The taxonomy of the genus is complex and controversial, concerning both the species as well as the subspecies systematics. Until 1850, only two species of Mazama were recognized. In 1878 Sir Victor Brooke performed a detailed review of this genus and recognized six species, but only four of them were well established. In 1898, Lydekker identified seven species, six of them clearly distinguishable. However, when Allen (1915) performed the first systematic review of the genus Mazama, he recognized 16 forms of Rev. Mus.Abstract: The genus Mazama (brocket deer) constitutes successful adaptive radiation, with a wide distribution in the Neotropical region. However, the taxonomy and systematics of its species and subspecies is still controversial. The objective of this contribution was to carry out a comparative craniometric study of specimens deposited in Brazilian museums of M. gouazoubira (Mg) and M. nemorivaga (Mn), in order to characterize these cryptic species. We performed 36 measures on 87 skulls of adult specimens (Mg = 32 females and 27 males; Mn = 14 females and 14 males). The sample was compared by analysis of variance and multivariate analysis of principal components and discriminant. In most cranial measurements, males and females of M. gouazoubira were 5% larger, with the exception of 3 measures: premolar-prosthion, basifacial axis, and least breadth between the orbits, that were larger in males and females of M. nemorivaga. This study showed significant differences between the two taxa that would validate the distinction of both species. To examine in more detail the dynamics of the variation of these two taxa it is necessary to increase the sample size in order to analyse them in a geographical and genetic context. Resumen: Diferenciación craniométrica de las especies de corzuelas pardas de Brasil. El géneroMazama constituye una exitosa radiación adaptativa, con una amplia distribución en la región Neotropical. Sin embargo, la taxonomía y sistemática sus especies y subespecies es todavía motivo de controversias. El objetivo de esta contribución fue realizar un estudio craneométrico comparativo de ejemplares depositados en museos de Brasil de M. gouazoubira (Mg) y M. nemorivaga (Mn), con el fin de caracterizar estas especies cripticas. Se tomaron 36 medidas en 87 cráneos de ejemplares adultos (Mg = 32 hembras y 27 machos; Mn = 14 hembras y 14 machos). La muestra se comparó mediante análisis de la varianza y análisis multivariados de componentes principales y discriminante. En la mayoría de las medidas craneanas los ejemplares machos y hembras de M. gouazoubira fueron un 5% más grandes, con la excepción de 3 medidas: premolar -prosthion, eje basifacial y el ancho menor entre orbitas, que presentaro...

Resurrection of the genus Subulo for the gray brocket deer, with designation of a neotype

“…The external body measurements and craniometrics of this new type series of S. gouazoubira were within the range of values recorded for this species (Rossi 2000; González et al 2018). The designation of a subadult individual as a candidate to neotype was considered for being the only male with a full set of cranial characters, such as antlers.…”

“…Yet, some authors considered M. nemorivaga as a subspecies of M. gouazoubira (Hershkovitz 1951; Cabrera 1961; Pinder and Leeuwenberg 1997). Currently, these two species are very well separated by morphology (Rossi 2000; González et al 2018), cytogenetics (Fiorillo et al 2013), molecular data (Duarte et al 2008), and reproductive isolation (Carranza et al 2017; Galindo et al 2021a). Smith (1827) originally described three species under the subgenus Subulo : Cervus (Subulo) rufus (= M. americana ), Cervus (Subulo) simplicicornis ( = M. gouazoubira ), and Cervus (Subulo) nemorivagus (= M. gouazoubira sensu Azara).…”

“…Additionally, we provide the adult cranial measurements and pictures of the skulls and mandibles of the female specimens with permanent dentition for future reference (see Supplementary Data SD2, SD3, and SD6). In the Brazilian population, the external body and cranial measurement variations of S. gouazoubira have been described as having a latitudinal trend, with specimens from northeastern Brazil being smaller than individuals from the southern regions of the country (Rossi 2000;Black-Décima et al 2010;González et al 2018).…”

Morphology, Taxonomy and Zoogeography of Argentinean Mammals: A tribute to José Yepes

“…El homenaje se cierra con la contribución de González et al (2018), quienes presentan una revisión morfológica para el género Mazama en Brasil, con énfasis en las especies del clado gris Mazama gouazoubira y Mazama nemorivaga.…”