Strict consensus tree from three most parsimonious trees of Bai et al. (2016), each with 96 steps |
Differing hypotheses of the scissor apparatus' function; B=defensive (Bai et al., 2018) |
Type specimen of Aethiocarenus burmanicus |
Grant viridifluvius (a) and Chimaeroblattina brevipes (b), with respective putative models (Vršansky et al., 2018) |
Rather more questionable are the methods Vršansky et al. (2018) used to infer the phylogenetic position of Al. brachyelytrus and kin, from which they concluded that these roachoids are in fact members of the Blattaria (true cockroaches and termites; Inward et al., 2007; Legendre et al., 2015). Rather than try to test the conclusions of Bai et al. (2016, 2018) by utilizing the character matrix of Bai et al. (2016), their dataset consisted of all known alienopterids excepting Alienopterella, an undescribed alienopterid from the Crato Formation, and Ae. burmanicus; several taxa belonging to the Mesozoic dictyopteran superfamily Umenocoleoidea, a taxon that is minus Umenocoleus equivalent to the Cratovitismoidea of Nel et al. (2014); and one other dictyopteran outgroup. Outgroups from other insect clades (as in Bai et al. [2016, 2018]) are conspicuously absent. As the sampling of Vršansky et al. (2018) overlaps little with previous phylogenies, no comparisons can be drawn with the studies of Bai et al. (2016, 2017), which attenuates the replicability of any conclusions drawn from these data.
50% majority rule cladogram, bootstrapped (Vršansky et al., 2018) |
With this tree supported to their satisfaction, Vršansky et al. (2018) propose sinking the Alienoptera to familial level within their conception of Umenocoleoidea, with Aethiocarenidae a junior synonym of the Alienopteridae. Since the Umenocoleoidea have been "proven to possess standard cockroach morphology" (Vršansky et al., 2018), they are assigned to the order Blattaria. No revised definition of the Blattaria including Alienopteridae is provided. Vršansky et al. (2018) excuse this by asserting that, first, "orders are not truly formalized units" (perhaps alluding to the fact that these are not under the purview of the International Code of Zoological Nomenclature); and second, that alienopterids' cockroach identity is axiomatic given their position within the Umenocoleoidea, making synonymization superfluous.
Forewing of Strephocladus permianus (Anthracoptilidae), with arrows marking M and Cu (Guan et al., 2016) |
Reconstruction of Mesotitan (formerly Clatrotitan) andersoni (Mesotitanini), photographed by John Augier |
In the end, there is nothing resembling consensus on the phylogenetic relationship of the Umenocoleoidea to extant Dictyoptera, or indeed the phylogeny of fossil Dictyoptera in general; and by granting the question of phylogeny only superficial coverage, Vršansky et al. (2018) fail to convince that the Alienopteridae are indeed umenocoleoids, and moreover, that by being umenocoleoids these are not stem-group Mantodea. Before we can wrangle with alienopterids' ordinal assignment, concerted effort at synthesizing a comprehensive picture of dictyopteran phylogeny must be made.
Well, it is almost 2019, and we are only partway to the imagined dystopias of yesteryear.
*An (arguable) model of phylogenetic inference that holds the phylogeny which requires the least amount of ad hoc character state changes is the optimal one, in keeping with Occam's Razor.
†Named for "a grant (financial support)" (Vršansky et al., 2018). I applaud the name choice.
‡With downward-directed mandibles.
§Non-parametric bootstrapping is a statistical method first applied to phylogenetics by Felsenstein (1985): it entails simulating datasets (pseudoreplicates) from subsets of the actual dataset, which are sampled with replacement. Confidence in a given node's existence is then expressed as the percentage of pseudoreplicates in which it appears. Hence, the clade that here excludes Vitisma and Liberiblattina was recovered in 90% of all pseudoreplicates (Vršansky et al., 2018).
||An internal node on a phylogeny that cannot be resolved into a dichotomy.
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