Twenty-seven Pachycrocuta brevirostris coprolites from Taurida Cave (Early Pleistocene) were studied. Eggs of parasitic worms were found in 6 of them (22.2%). Eggs of Trematoda species were identified among them, as were eggs of Taenia, Toxocara, and Capillaria. Toxocara eggs were the most common; they were found in 15% of the coprolites. This is the earliest evidence of P. brevirostris infection by these groups of helminths.

Members of the copepod family Caligidae are some of the most common parasites of marine fishes. There are 503 recognized species divided into about 30 genera, with 75% of species belonging to the 2 largest genera, Caligus and Lepeophtheirus. More than 30 caligid species are known to cause serious pathologic changes as ectoparasites in marine teleost aquaculture. This study was undertaken to provide a key to the valid genera of Caligidae, to examine their morphology in new detail with confocal laser scanning microscopy, and to review uncertainties concerning boundaries between several genera. There have been several substantial changes to the taxonomy of Caligidae over the last decade: Metacaligus, Sciaenophilus, and Sinocaligus have been synonymized with Caligus and the validity of Midias has been questioned. Here, we formally propose that Midias and Markevichus are junior subjective synonyms of Caligus. In total, we recognize 27 valid genera; provide a key to these genera; present confocal laser scanning micrographs for 25 of the genera, many of which have never been imaged before; and highlight helpful diagnostic features used in the key. We also discuss some concerns regarding the generic boundaries separating Belizia, Caritus, Parapetalus, Parechetus, Pseudechetus, and Synestius from Caligus and those separating Anuretes, Pseudanuretes, and Mappates from Lepeophtheirus.

The present work includes the description of Gyrinicola pilyolcatzin n. sp. (Nematoda: Oxyurida) collected from the large intestine of tadpoles of the Montezuma frog, Rana montezumae. Nuclear DNA and mitochondrial DNA generated via a combination of Sanger and Next Generation shotgun sequencing were used to reconstruct the species in a phylogenetic context, by including the other 4 recognized species in the genus present in North America, namely, Gyrinicola batrachiensis, Gyrinicola armatus, Gyrinicola gulabrevioris, and Gyrinicola moohsia. The distinctiveness of the species was supported by an analysis of branching patterns using Bayesian Poisson tree processes. We used morphometric evidence to enumerate the diagnostic characters that define members of this unique clade within the genus. The species shares a common ancestor with G. gulabrevioris and G. moohsia; yet it is meristically similar to G. armatus. This is the first species of the genus described in Mexico and the fifth species described in the Nearctic, as it is present in the Transvolcanic Axis of Mexico, which acts as a transition zone between the Nearctic and the Neotropics. A dichotomous key to the species in the Nearctic is offered.