@article {48122, title = {Tackling an intractable problem: Can greater taxon sampling help resolve~relationships within the Stenopelmatoidea (Orthoptera: Ensifera)?}, journal = {Zootaxa}, volume = {4291}, year = {2017}, month = {Nov-07-2017}, pages = {1}, abstract = {

The relationships among and within the families that comprise the orthopteran superfamily Stenopelmatoidea (suborder Ensifera) remain poorly understood. We developed a phylogenetic hypothesis based on Bayesian analysis of two nuclear ribosomal and one mitochondrial gene for 118 individuals (84 de novo and 34 from GenBank). These included Gryllacrididae from North, Central, and South America, South Africa and Madagascar, Australia and Papua New Guinea; Stenopelmatidae from North and Central America and South Africa; Anostostomatidae from North and Central America, Papua New Guinea, New Zealand, Australia, and South Africa; members of the Australian endemic Cooloola (three species); and a representative of Lezina from the Middle East. We also included representatives of all other major ensiferan families: Prophalangopsidae, Rhaphidophoridae, Schizodactylidae, Tettigoniidae, Gryllidae, Gryllotalpidae and Myrmecophilidae and representatives of the suborder Caelifera as outgroups. Bayesian analyses of concatenated sequence data supported a clade of Stenopelmatoidea inclusive of all analyzed members of Gryllacrididae, Stenopelmatidae, Anostostomatidae, Lezina and Cooloola. We found Gryllacrididae worldwide to be monophyletic, while we did not recover a monophyletic Stenopelmatidae nor Anostostomatidae. Australian Cooloola clustered in a clade composed of Australian, New Zealand, and some (but not all) North American Anostostomatidae. Lezina was included in a clade of New World Anostostomatidae. Finally, we compiled and compared karyotypes and sound production characteristics for each supported group. Chromosome number, centromere position, drumming, and stridulation differed among some groups, but also show variation within groups. This preliminary trait information may contribute toward future studies of trait evolution. Despite greater taxon sampling within Stenopelmatoidea than previous efforts, some relationships among the families examined continue to remain elusive.

}, keywords = {Anostostomatidae, Cooloola, drumming, genetic, Gryllacrididae, karyotype, Lezina, Orthoptera, sound production, Stenopelmatidae}, issn = {1175-5326}, doi = {10.11646/zootaxa.4291.110.11646/zootaxa.4291.1.1}, url = {https://biotaxa.org/Zootaxa/issue/view/zootaxa.4291.1https://biotaxa.org/Zootaxa/article/view/zootaxa.4291.1.1}, author = {Amy G. Vandergast and David B. Weissman and Dustin A. Wood and D. C. F. Rentz and Corinna S. Bazelet and Norihiro Ueshima} } @article {40435, title = {Neuroanatomy and Physiology of the Complex Tibial Organ of an Atympanate Ensiferan, Ametrus tibialis (Brunner von Wattenwyl, 1888) (Gryllacrididae, Orthoptera) and Evolutionary Implications}, journal = {Brain, Behavior and Evolution}, volume = {71}, year = {2008}, month = {Jan-01-2008}, pages = {167 - 180}, abstract = {

We investigated the neuroanatomy and physiology of the complex tibial organ of an atympanate ensiferan, the Gryllacridid Ametrus tibialis. This represents the first analysis of internal mechanoceptors in Gryllacridids. The complex tibial organ is tripartite consisting of a subgenual organ, intermediate organ and a homologue organ to the crista acustica of tympanate ensiferan taxa of Tettigoniidae, Haglidae, and Anostostomatidae. The crista homologue contains 23 \± 2 receptor neurons in the foreleg. It is associated with the leg trachea and found serially in all three thoracic leg pairs. Central projections of the sensory nerve of the complex tibial organ bifurcate in two lobes in the prothoracic ganglion, which do not reach the midline. The axonal endings project into the mVAC, the main vibratory-auditory neuropile of Ensifera. Recordings of the tibial nerve show that the tibial organ is sensitive to vibrational stimuli with a minimum threshold of 0.02 to 0.05 ms\–2 at 200\–500 Hz, but rather insensitive to airborne sound. The main function of the tibial organ is therefore vibration sensing, although the specific function of the crista homologue remains unclear. The presence of the crista acustica homologue is interpreted in phylogenetic context. Because ensiferan phylogeny is unresolved, two alternative scenarios can be deduced: (a) the crista homologue is a precursor structure which was co-opted as an auditory system and represent a morphologically highly specialized structure before acquisition of its new function; (b) a previously functional tibial ear is evolutionary reduced but the neuronal structures are maintained. Based on comparison of neuroanatomical details, the crista acustica homologue of A. tibialis could present the neuronal complement of an ear evolutionary precursor structure, which was successively made sensitive to airborne sound by elaboration of cuticular tympana, auditory spiracle and trachea for sound propagation.

}, keywords = {Ametrus tibialis, auditory system, Ensifera, Gryllacrididae, hearing organ, neuroanatomy, vibrational communication}, issn = {0006-8977}, doi = {10.1159/000114405}, url = {http://www.karger.com/doi/10.1159/000114405}, author = {Strau{\ss}, Johannes and Lakes-Harlan, Reinhard} }