Publication Date


Advisor(s) - Committee Chair

Keith Philips (chair), Albert Meier, Jarrett Johnson

Degree Program

Department of Biology

Degree Type

Master of Arts


A new genus, Coleotestudo, is proposed for the American species currently placed in the genus Niptus LeConte and are transferred herein. Two new species from Mexico are also described as C. potosi n. sp. and C. nahua n. sp. Distinguishing morphological characteristics for the North American Coleotestudo species are given. The combined set of morphological evidence, DNA sequence data, and a Western New World distribution strongly support the hypothesis that Coleotestudo does not share a recent common ancestor with N. hololeucus and both represent unrelated clades of spider beetles.

During the summer of 2021, Coleotestudo was collected mainly from caves and the burrows and nests of vertebrates across most of their known distribution within the United States. Two mitochondrial genes (CO1, 16S) and one nuclear gene (28S) were amplified and sequenced from specimens from each locality. Phylogenetic trees were constructed via Bayesian and maximum parsimony analyses, and 13 distinct lineages were identified using both phylogenetic molecular and, in most cases, morphological data.

Four new species are described for the recently described genus Coleotestudo Chambliss and Philips. The newly described species are Coleotestudo eagari, Coleotestudo jackeri, Coleotestudo microtexanum, and Coleotestudo taos. Models produced using the Generalized Mixed Coalescent Method (GMYC) with DNA fragments for Coleotestudo show strong support of three independent lineages for species delimitation among populations within a subclade of Coleotestudo

Ecological niche modeling was used to estimate distribution patterns of Coleotestudo taxa during the Last Glacial Maximum (21 Ka) and the late Pliocene (3.2 Ma) based on paleoclimatic data, revealing possible avenues for speciation and diversification within the genus. The historical distribution of the currently sympatric Coleotestudo giuliani and C. ventriculus, sensu lato estimated by ENM shows the isolation of each species to different desert glacial refugia during the Pleistocene and late Pliocene.


Biodiversity | Ecology and Evolutionary Biology | Entomology | Evolution | Life Sciences