Positional behavior and substrate use of Micromys minutus (Rodentia: Muridae): Insights for understanding primate origins

Urbani, Bernardo; Youlatos, Dionisios

doi:10.1016/j.jhevol.2012.10.006

Cited by 26 publications

(30 citation statements)

References 54 publications

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“…Other comparative studies have shown that some terminal-branch specialists such as arboreal marsupials (Cartmill 1974b;Lemelin 1999;Rasmussen 1990;Rasmussen and Sussman 2007;Schmitt and Lemelin 2002;Shapiro and Young 2010;Youlatos 2008), and chameleons (Cartmill 1974b;Herrel et al 2012) possess a hand and foot morphology that is functionally similar to that of primates, suggesting evolutionary convergence of grasping. Recent studies have also demonstrated that species lacking primate grasping adaptations, including some squirrels (Orkin and Pontzer 2011;Samaras and Youlatos 2010) and mice (Byron et al 2011;Urbani and Youlatos 2013), are also capable of moving, feeding, and foraging on thin and terminal branches.…”

Section: Introductionmentioning

confidence: 99%

Substrate Diameter and Orientation in the Context of Food Type in the Gray Mouse Lemur, Microcebus murinus: Implications for the Origins of Grasping in Primates

Toussaint¹,

Herrel

Ross

et al. 2015

Int J Primatol

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Grasping is a widespread behavior among tetrapod vertebrates. In primates, the hands and feet are involved in many tasks including arboreal locomotion and food acquisition. Yet, the origin and the evolution of prehensile capacities, which are highly diversified across this group, remain open for inquiry. Some researchers suggest that grasping evolved in an arboreal habitat consisting of fine branches associated with insect predation and/or fruit and flower exploitation. However, few studies have tested the importance of arboreal conditions and diet, e.g., frugivorous, omnivorous, on the use of the hands in food grasping. The aim of this study was to link substrate use and food grasping strategies quantitatively to test hypotheses concerning primate grasping origins. We studied a species often described as a good ecological model to study the origin of grasping in primates, Microcebus murinus, and quantified its spontaneous substrate use (diameter and orientation) in an unconstrained environment while presenting them with different food types (static and mobile). We show that 1) Microcebus murinus appears to be an opportunistic rather than a specialist user of fine branches as suggested previously, at least under laboratory conditions; and 2) food properties had an impact on the use of the hands vs. the mouth, with the hands being used more for the Int J Primatol (2015) 36:583-604 grasping of mobile prey. Our results are consistent with hypotheses for primate origins that propose adaptations to both a narrow branch environment and visually directed prey capture with the hands. However, additional studies in the wild are needed to understand better the origin and increased use of the hands in primates grasping and manipulation.

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Section: Introductionmentioning

confidence: 99%

Substrate Diameter and Orientation in the Context of Food Type in the Gray Mouse Lemur, Microcebus murinus: Implications for the Origins of Grasping in Primates

Toussaint¹,

Herrel

Ross

et al. 2015

Int J Primatol

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“…Although there remains disagreement in the literature as to primate ancestral body size (Soligo and Martin, , ; Silcox et al., ), a presumed small body size for the primate ancestral condition (i.e., less than 100 g) (e.g., Cartmill, ; Gebo, ) is well supported by the small size of the earliest fossil euprimates (Silcox et al., ; Fleagle, ), and by the fact that agreement between paleontological and molecular estimates of primate divergence times improves when molecular models account for the fast life history patterns associated with a small bodied last common ancestor (Steiper and Seiffert, ). Accordingly, insights on primate locomotor evolution have been gained from studies examining the unique biomechanical benefits and challenges encountered by small primates or other small mammals moving quadrupedally on arboreal substrates (Pridmore, ; Preuschoft et al., ; Arms et al., ; Lemelin et al., ; Lammers and Biknevicius, ; Lammers et al., ; Lemelin and Schmitt, ; Lammers, , ; Lammers and Gauntner, ; Schmidt, ; Youlatos, ; Young, ; Samaras and Youlatos, ; Schmidt and Fischer, , ; Shapiro and Young, , ; Byron et al., ; Lammers and Zurcher, ; Stevens et al., ; Urbani and Youlatos, ; Shapiro et al., ; Chadwell and Young, ; Hesse et al., ; Karantanis et al., ). Most previous studies of primate quadrupedalism have been restricted to the analysis of symmetrical gaits.…”

mentioning

confidence: 99%

“…ancestor (Steiper and Seiffert, 2012). Accordingly, insights on primate locomotor evolution have been gained from studies examining the unique biomechanical benefits and challenges encountered by small primates or other small mammals moving quadrupedally on arboreal substrates (Pridmore, '94;Preuschoft et al, '96;Arms et al, 2002;Lemelin et al, 2003;Lammers and Biknevicius, 2004;Lammers et al, 2006;Lemelin and Schmitt, 2007;Lammers, 2007Lammers, , 2009Lammers and Gauntner, 2008;Schmidt, 2008;Youlatos, 2008;Young, 2009;Samaras and Youlatos, 2010;Fischer, 2010, 2011;Young, 2010, 2012;Byron et al, 2011;Lammers and Zurcher, 2011;Stevens et al, 2011;Urbani and Youlatos, 2013;Shapiro et al, 2014;Chadwell and Young, 2015;Hesse et al, 2015;Karantanis et al, 2015). Most previous studies of primate quadrupedalism have been restricted to the analysis of symmetrical gaits.…”

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confidence: 99%

Effects of Substrate Size and Orientation on Quadrupedal Gait Kinematics in Mouse Lemurs (Microcebus murinus)

2016

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As the smallest living primate, the mouse lemur is a suitable model for reconstructing the locomotor mechanisms by which primate ancestors might have responded to the challenges of an arboreal environment. In this study, we tested the effects of substrate diameter and orientation on quadrupedal gait kinematics in mouse lemurs (Microcebus murinus). Mouse lemurs highly preferred asymmetrical to symmetrical gaits as they moved across a flat board and poles of three diameters (2.5, 1.0, and 0.5 cm), set at horizontal, 30°inclined, and 30°declined orientations. During symmetrical gaits, mouse lemurs used diagonal sequence walking and ambling gaits on the same substrates and at the same duty factors for which some similarly sized nonprimate mammals use lateral sequence gaits, suggesting that reliance on diagonal sequence walking in primates may not be explicitly a response to body size relative to substrate diameter. When using asymmetrical gaits, kinematic adjustments to small diameter and/or nonhorizontal substrates included a preference for transverse gallops over other gaits, the avoidance of whole-body suspensions, increases in limb contact duration, and increases in the time interval between the landing of trailing and leading limbs. All of these adjustments are consistent with increasing locomotor stability by dampening center of mass movements and reducing the forces imparted to the substrate. Like mouse lemurs, small-bodied ancestral primates likely used symmetrical gaits occasionally, but more frequently used asymmetrical gaits that were adjusted in response to challenging substrates. Therefore, asymmetrical gait dynamics should be incorporated into hypotheses addressing early primate locomotor evolution.

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“…Moreover, earlier studies of lab mice and the rodent genus Peromyscus have emphasized the role of tail use, increased talar neck angle, and first metatarsal morphology in climbing behaviors (Siegel, ; Siegel and Van Meter, ; Siegel and Jones, ). Recent work with the harvest mouse ( Micromys minutus ; Urbani and Youlatos, ) substantiate this approach that early stages of primate evolution can be modeled with living rodent species. By combining tiny‐size and secure hallucal grasping, those authors demonstrate that animals not typically viewed as being specialized for the fine‐branch niche can nevertheless exploit this habitat to a degree of proficiency that is between the hypothesized Stages 2 and 3 of primate evolution.…”

Section: Introductionmentioning

confidence: 94%

Mouse hallucal metatarsal cross‐sectional geometry in a simulated fine branch niche

Byron

Herrel

Pauwels

et al. 2015

Journal of Morphology

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Mice raised in experimental habitats containing an artificial network of narrow "arboreal" supports frequently use hallucal grasps during locomotion. Therefore, mice in these experiments can be used to model a rudimentary form of arboreal locomotion in an animal without other morphological specializations for using a fine branch niche. This model would prove useful to better understand the origins of arboreal behaviors in mammals like primates. In this study, we examined if locomotion on these substrates influences the mid-diaphyseal cross-sectional geometry of mouse metatarsals. Thirty CD-1/ICR mice were raised in either arboreal (composed of elevated narrow branches of varying orientation) or terrestrial (flat ramps and walkways that are stratified) habitats from weaning (21 days) to adulthood (≥4 months). After experiments, the hallucal metatarsal (Mt1) and third metatarsal (Mt3) for each individual were isolated and micro-computed tomography (micro-CT) scans were obtained to calculate mid-shaft cross-sectional area and polar section modulus. Arboreal mice had Mt1s that were significantly more robust. Mt3 cross sections were not significantly different between groups. The arboreal group also exhibited a significantly greater Mt1/Mt3 ratio for both robusticity measures. We conclude that the hallucal metatarsal exhibits significant phenotypic plasticity in response to arboreal treatment due to habitual locomotion that uses a rudimentary hallucal grasp. Our results support the hypothesis that early adaptive stages of fine branch arboreality should be accompanied by a slightly more robust hallux associated with the biomechanical demands of this niche.

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Positional behavior and substrate use of Micromys minutus (Rodentia: Muridae): Insights for understanding primate origins

Cited by 26 publications

References 54 publications

Substrate Diameter and Orientation in the Context of Food Type in the Gray Mouse Lemur, Microcebus murinus: Implications for the Origins of Grasping in Primates

Substrate Diameter and Orientation in the Context of Food Type in the Gray Mouse Lemur, Microcebus murinus: Implications for the Origins of Grasping in Primates

Effects of Substrate Size and Orientation on Quadrupedal Gait Kinematics in Mouse Lemurs (Microcebus murinus)

Mouse hallucal metatarsal cross‐sectional geometry in a simulated fine branch niche

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