A new species of Rhinatrema Duméril &amp;amp; Bibron (Amphibia: Gymnophiona: Rhinatrematidae) from Guyana

Gower, David J.; Wilkinson, Mark; Sherratt, Emma; Kok, Philippe J. R.

doi:10.11646/zootaxa.2391.1.3

Cited by 14 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…they are encountered in pitfall traps; Gower et al. ). These species possess the most well‐developed visual systems, with exposed eyes and maintenance of visual innervation (Wake, ; Fritzsch & Wake, ).…”

Section: Discussionmentioning

confidence: 99%

“…Early diverging caecilian species are considered to be predominantly leaf litter inhabitants, rather than deep-tunnel dwellers (e.g. they are encountered in pitfall traps; Gower et al 2010). These species possess the most well-developed visual systems, with exposed eyes and maintenance of visual innervation (Wake, 1985;Fritzsch & Wake, 1988).…”

Section: Evolution Of Inner Ear Traits Within Caeciliansmentioning

confidence: 99%

See 1 more Smart Citation

Influence of fossoriality on inner ear morphology: insights from caecilian amphibians

Maddin

Sherratt

2014

Journal of Anatomy

Self Cite

View full text Add to dashboard Cite

It is widely accepted that a relationship exists between inner ear morphology and functional aspects of an animal's biology, such as locomotor behaviour. Animals that engage in agile and spatially complex behaviours possess semicircular canals that morphologically maximise sensitivity to correspondingly complex physical stimuli. Stemming from the prediction that fossorial tetrapods require a well-developed sense of spatial awareness, we investigate the hypothesis that fossoriality leads to inner ear morphology that is convergent with other spatially adept tetrapods. We apply morphometrics to otic capsule endocasts of 26 caecilian species to quantify aspects of inner ear shape, and compare these with a sample of frog and salamander species. Our results reveal caecilians (and also frogs) possess strongly curved canals, a feature in common with spatially adept species. However, significantly shorter canals in caecilians suggest reduced sensitivity, possibly associated with reduced reliance on vestibulo-ocular reflexes in this group of visually degenerate tetrapods. An elaboration of the sacculus of caecilians is interpreted as a unique adaptation among amphibians to increase sensitivity to substrate-borne vibrations transmitted through the head. This study represents the first quantitative analyses of inner ear morphology of limbless fossorial tetrapods, and identifies features within a new behavioural context that will contribute to our understanding of the biological consequences of physical stimuli on sensory function and associated morphological evolution.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Evolution Of Inner Ear Traits Within Caeciliansmentioning

confidence: 99%

Influence of fossoriality on inner ear morphology: insights from caecilian amphibians

Maddin

Sherratt

2014

Journal of Anatomy

Self Cite

View full text Add to dashboard Cite

show abstract

“…Observations of external morphology are based on a series of adult Rhinatrema bivittatum collected in multiple expeditions since 2004 from Patawa, Kaw Mountains, French Guiana by Mark Wilkinson, David Gower, Alex Kupfer and Gabriela Bittencourt (specimen numbers given in Gower et al . ). Due to the rarity of the species, only a single animal was available for histological study.…”

Section: Methodsmentioning

confidence: 97%

“…Gower et al . ). Here, we describe and illustrate the eye of R. bivittatum , compare it with those of other caecilians and consider its implications for understanding the evolution of the caecilian visual system.…”

Section: Introductionmentioning

confidence: 97%

The eye of the caecilian Rhinatrema bivittatum (Amphibia: Gymnophiona: Rhinatrematidae)

Mohun

Wilkinson

2014

Acta Zoologica

Self Cite

View full text Add to dashboard Cite

Mohun, S.M. and Wilkinson, M. 2015. The eye of the caecilian Rhinatrema bivittatum (Amphibia: Gymnophiona: Rhinatrematidae). -Acta Zoologica (Stockholm) 96: 147-153.The reduction in the visual system of the Gymnophiona has been noted by many authors. Adult caecilian amphibians eyes are small, covered by skin and sometimes bone, with retinal cells that contain only rod opsins and co-option of structures usually associated with the visual system used for novel sensory structures and functions. Here, we provide a description of the eye of Rhinatrema bivittatum, the first of any rhinatrematid caecilian, and consider its significance for our understanding of the nature of the eye in the last common ancestor of living caecilians. Characters discovered include zonule fibres, an aqueous humour and the remnants of an attachment that could be a protractor lentis muscle.

show abstract

“…Field observations suggest that adults of terrestrial caecilians vary from dedicated burrowers to more surface-active animals (e.g. Burger et al 2004;Gower et al 2004Gower et al , 2010, although detailed ecological studies are lacking for most species. As far as is known, all adult caecilians practice some head-first burrowing, even the aquatic and semi-aquatic species (Moodie 1978), but burrowing ability differs among species (Ducey et al 1993;Herrel and Measey 2010).…”

Section: Introductionmentioning

confidence: 99%

Evolution of Cranial Shape in Caecilians (Amphibia: Gymnophiona)

et al. 2014

Self Cite

View full text Add to dashboard Cite

Insights into morphological diversification can be obtained from the ways the species of a clade occupy morphospace. Projecting a phylogeny into morphospace provides estimates of evolutionary trajectories as lineages diversified information that can be used to infer the dynamics of evolutionary processes that produced patterns of morphospace occupation. We present here a large-scale investigation into evolution of morphological variation in the skull of caecilian amphibians, a major clade of vertebrates. Because caecilians are limbless, predominantly fossorial animals, diversification of their skull has occurred within a framework imposed by the functional demands of head-first burrowing. We examined cranial shape in 141 species, over half of known species, using X-ray computed tomography and geometric morphometrics. Mapping an existing phylogeny into the cranial morphospace to estimate the history of morphological change (phylomorphospace), we find a striking pattern: most species occupy distinct clusters in cranial morphospace that closely correspond to the main caecilian clades, and each cluster is separated by unoccupied morphospace. The empty spaces in shape space are unlikely to be caused entirely by extinction or incomplete sampling. The main caecilian clades have different amounts of morphological disparity, but neither clade age nor number of species account for this variation. Cranial shape variation is clearly linked to phyletic divergence, but there is also homoplasy, which is attributed to extrinsic factors associated with head-first digging: features of caecilian crania that have been previously argued to correlate with differential microhabitat use and burrowing ability, such as subterminal and terminal mouths, degree of temporal fenestration (stegokrotaphy/ zygokrotaphy), and eyes covered by bone, have evolved and many combinations occur in modern species. We find evidence of morphological convergence in cranial shape, among species that have eyes covered by bone, resulting in a narrow bullet-shaped head. These results reveal a complex history, including early expansion of morphospace and both divergent and convergent evolution resulting in the diversity we observe today.

show abstract

A new species of Rhinatrema Duméril & Bibron (Amphibia: Gymnophiona: Rhinatrematidae) from Guyana

Cited by 14 publications

References 11 publications

Influence of fossoriality on inner ear morphology: insights from caecilian amphibians

Influence of fossoriality on inner ear morphology: insights from caecilian amphibians

The eye of the caecilian Rhinatrema bivittatum (Amphibia: Gymnophiona: Rhinatrematidae)

Evolution of Cranial Shape in Caecilians (Amphibia: Gymnophiona)

Contact Info

Product

Resources

About