Revision of Madagascar's Dwarf Lemurs (Cheirogaleidae:Cheirogaleus): Designation of Species, Candidate Species Status and Geographic Boundaries Based on Molecular and Morphological Data

Abstract

The genus Cheirogaleus, the dwarf lemurs, is a radiation of strepsirrhine primates endemic to the island of Madagascar. The dwarf lemurs are taxonomically grouped in the family Cheirogaleidae (Infraorder: Lemuriformes) along with the genera Microcebus, Mirza, Allocebus, and Phaner. The taxonomic history of the genus Cheirogaleus has been controversial since its inception due to a paucity of evidence in support of some proposed species. In this study, we addressed this issue by expanding the geographic breadth of samples by 91 individuals and built upon existing mitochondrial (cytb and COII) and nuclear (FIBA and vWF) DNA datasets to better resolve the phylogeny of Cheirogaleus. The mitochondrial gene fragments D-loop and PAST as well as the CFTR-PAIRB nuclear loci were also sequenced. In agreement with previous genetic studies, numerous deep divergences were resolved in the C. major, C. minor and C. medius lineages. Four of these lineages were segregated as new species, seven were identified as confirmed candidate species, and four were designated as unconfirmed candidate species based on comparative mitochondrial DNA sequence data gleaned from the literature or this study. Additionally, C. thomasi was resurrected. Given the widespread distribution of the genus Cheirogaleus throughout Madagascar, the methodology employed in this study combined all available lines of evidence to standardize investigative procedures in a genus with limited access to type material and a lack of comprehensive sampling across its total distribution. Our results highlighted lineages that likely represent new species and identified localities that may harbor an as-yet undescribed cryptic species diversity pending further field and laboratory work.

How many species of mammals are there?

“…An incredible 148 primate species have been recognized since the publication of MSW3, including 67 de novo and 81 splits (Tables 1 and 3), a taxonomic outcome that is striking for our closest human relatives. Taxonomic revisions have centered around New World monkey families (Cebidae- Boubli et al 2012; PitheciidaeMarsh 2014) and many de novo species descriptions also occurred among Malagasy lemurs (Cheirogaleidae- Lei et al 2014;Lepilemuridae-Louis et al 2006). However, persistent taxonomic uncertainty within the family Cercopithecidae (Groves 2007a(Groves , 2007bMittermeier et al 2013) suggests that the species-level diversity of Primates is not yet stable and will continue to fluctuate.…”

Range Extension and Behavioural Observations of the Recently Described Sheth's Dwarf Lemur (Cheirogaleus shethi)

“…With the exception of the mouse lemurs, Microcebus [Schmid, 1998;Atsalis, 2000], Cheirogaleus are the only known primates to undergo extended periods of seasonal hibernation; this makes them very difficult to study during the periods they spend hidden within sleeping sites living off fat reserves stored in their tails [Wright and Martin, 1995;Schülke and Ostner, 2007;Mittermeier et al, 2010]. Unlike other nocturnal lemurs, whose geographic ranges are constrained between river systems (interriver system vicariance [Olivieri et al, 2007;Rakotondranary et al, 2011]), many Cheirogaleus species have large distributions spread throughout most of Madagascar [Mittermeier et al, 2010;Lei et al, 2014;Herrera et al, 2016]. This wide range includes several zones of Cheirogaleus sympatry that make it difficult for biogeographers and conservationists to map speciesspecific ranges and population distributions [Lahann, 2008;Lei et al, 2014].…”

“…Unlike other nocturnal lemurs, whose geographic ranges are constrained between river systems (interriver system vicariance [Olivieri et al, 2007;Rakotondranary et al, 2011]), many Cheirogaleus species have large distributions spread throughout most of Madagascar [Mittermeier et al, 2010;Lei et al, 2014;Herrera et al, 2016]. This wide range includes several zones of Cheirogaleus sympatry that make it difficult for biogeographers and conservationists to map speciesspecific ranges and population distributions [Lahann, 2008;Lei et al, 2014]. To further complicate our understanding of Cheirogaleus distributions, modern mitogenomic approaches have revealed several new species, all with overlapping geographic ranges of varying sizes [Blanco et al, 2009;Groeneveld et al, 2009;Lei et al, 2014;Frasier et al, 2016].…”

“…This wide range includes several zones of Cheirogaleus sympatry that make it difficult for biogeographers and conservationists to map speciesspecific ranges and population distributions [Lahann, 2008;Lei et al, 2014]. To further complicate our understanding of Cheirogaleus distributions, modern mitogenomic approaches have revealed several new species, all with overlapping geographic ranges of varying sizes [Blanco et al, 2009;Groeneveld et al, 2009;Lei et al, 2014;Frasier et al, 2016].…”

Evolução morfológica no crânio de Lemuriformes (Primates:Strepsirrhini)

“…As seen in correlation tests, PCs 1, 2 and 3 showed a strong signal of co-selection Figure 3.6. This indicates that phenotypic divergence had This is not the first study to report extreme high levels of variance associated with PC1 in Cheirogaleidae (Groeneveld et al, 2011;Lei et al, 2014). Masters et al (2014) this family experienced at least four independent events of body size reduction, and that the ancestor malagasy primate was as large as living folivorous Lepilemuridae genus (Masters et al, 2014).…”