Eremobatidae, Kraepelin, 1899

Garcia, Erika L., Hansen, Quincy G. & Cushing, Paula E., 2024, Camel spider trait evolution demonstrates repeated patterns of convergence (Arachnida: Solifugae: Eremobatidae), Insect Systematics and Diversity 8 (1), pp. 1-23 : 17-18

Eremobatidae Phylogeny

Here we present a phylogenomic approach and a new phylo* genetic hypothesis for the North American camel spider family Eremobatidae . Our results, we believe, give implications for new generic designations such that the genera are represented by clades of shared ancestry. Despite our limited taxon sampling for other Eremobates species groups, and lack of representation for Eremothera and Eremocosta , we expect that the well*supported clades recovered in our phylogenomic hypotheses will hold con* sistent as some of these clades are supported by morphological traits. The clade consisting of Horribates , Eremobates , Eremorhax , Eremochelis imperialis , Hemerotrecha serrata , and Eremochelis kerni to Eremochelis branchi all comprise taxa that are consider* ably large eremobatid species compared to the other taxa included in this study. Members of this clade tend to be 20 mm or more in body length, with cheliceral length being above 4.0 mm, on average. Although we did not sample some of the characteristically large species of Eremocosta in our analysis, we suspect that Eremocosta will fall within this large body size eremobatid clade, as well as Eremothera .

Several clades were generally supported by the morphological characters we examined here, and we believe that this is preliminary evidence that may support new generic*level placements within Eremobatidae . At this time, given our data, taxon sampling and results, we suggest that the Hemerotrecha branchi species and the Hemerotrecha denticulata species group merits elevation to a gen* eric level rank in future taxonomic works. There are several implica* tions that suggest that the Hemerotrecha banksi species group could be elevated to a generic rank, however, further evidence is required to determine whether Eremochelis striodorsalis and Eremochelis kastoni could be included in the same generic level rank.

We suggest the following synonymies for future taxonomic con* sideration: Hemerotrecha branchi and Hemerotrecha xena , distin* guished by the presence or absence of papillae (Muma 1951), occur in various combinations within the same clade in our analysis, therefore are likely the same species with variable papillar morph* ologies. Second, Chanbria regalis Muma 1951 and Chanbria rectus Muma 1962 , distinguished by the slight dorsal curvature of the FF in C. regalis Muma 1951 , are also probable conspecifics ( Fig. 4 ). Additionally, E. flexacus and E. acrilobatus are complementary spe* cies of the male and female, respectively. And finally, E. oregonensis a morphologically similar species to E. bidepressus and was found nested within multiple E. bidepressus representatives, thus should be synonymized.

Figures

Fig. 4. Maximum likelihood topology of Eremobatidae inferred using IQ-TREE 2 and the 75% occupancy concatenated UCE matrix with taxa that rendered>10 UCE loci with outgroups removed.Nodal support for major clades refer to maximum likelihood bootstrap values (ML) on the left and local posterior probabilities estimated based on gene tree quartet frequencies in ASTRAL (MSC) on the right.Tip colors illustrate generic designations as per current eremobatid taxonomy. Male (left column) and female (right column) structures of eremobatid species are shown on the right of the topology. Images are ordered phylogenetically. A) Eremochelis andreasana (♂, DMNS ZA.41919;♀, DMNS ZA.40822). B) Hemerotrecha marathoni (♂, CNAN loan; ♀, CNAN loan). C) Hemerotrecha xena (♂, DMNS ZA.16469; ♀, DMNS ZA.42101). D) Eremochelis bilobatus (♂, DMNS ZA.17629; ♀, DMNS ZA.17359). E) Horribates spinigerus (♂, DMNS ZA.40086; ♀, AMNH_ Holotype). F) Chanbria regalis (♂, DMNS ZA.25443; ♀, DMNS ZA.25442). G) Hemerotrecha serrata (♂, DMNS ZA.16059; ♀, DMNS ZA.22169). H) Eremochelis flexacus (♂, DMNS ZA.16134; ♀, DMNS ZA.23593). I) Hemerotrecha parva (♂, DMNS ZA.42131; ♀, DMNS ZA.42131). J) Eremochelis larreae (♂, CASENT9033550; ♀, DMNS ZA.33721). K) Eremochelis insignatus (♂, DMNS ZA.28260; ♀, DMNS ZA.26390). L) Eremochelis striodorsalis (♂, DMNS ZA.31773; ♀, DMNS ZA.23593). M) Hemerotrecha californica (♂, DMNS ZA.18288; ♀, DMNS ZA.32217).All scale bars represent 1 mm.