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A catalog of the type specimens (holotypes, paratypes, lectotype, and paralectotype) of the species of the family Scenopinidae (Diptera) described by T. Becker, N.P. Krivosheina, and M.G. Krivosheina, which are stored in the collection of the Zoological Institute, Russian Academy of Sciences, in St. Petersburg, is presented. Photographs of the holotypes and lectotype and of their labels are given.

Horseshoe crabs as a group are renowned for their morphological conservatism punctuated by marked shifts in morphology associated with the occupation of non-marine environments and have been suggested to exhibit a consistent developmental trajectory throughout their evolutionary history. Here, we report a new species of horseshoe crab from the Ordovician (Late Sandbian) of Kingston, Ontario, Canada, from juvenile and adult material. This new species provides critical insight into the ontogeny and morphology of the earliest horseshoe crabs, indicating that at least some Palaeozoic forms had freely articulating tergites anterior to the fused thoracetron and an opisthosoma comprising 13 segments.

Premise of research. Abundant fossil and molecular evidence suggests that all extant conifer families were established by the Early Cretaceous. However, the recognition and understanding of the lineages that lead to the evolution of these extant families remain incomplete. Late Paleozoic to Early Mesozoic Voltziales conifers—also known as transitional conifers, usually with multilobed ovuliferous scales—have been hypothesized to be among the stem lineages of modern crown conifers. This article describes an exquisitely preserved voltzian seed cone from the Aptian-Albian of Mongolia that introduces new taxonomic diversity and morphological data into the complex pattern of conifer evolution. Methodology. Bulk lignite samples collected from the Tevshiin Govi locality were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. Fossils were examined using LM, SEM, and X-ray microtomography. Pivotal results. Krassilovia mongolica gen. et sp. nov. has seed cones with helically arranged, imbricated, and tightly interlocked bract-scale complexes. Each mature bract-scale complex consists of an inconspicuous bract partially fused to the stalk of a five-lobed scale. Three of the lobes are distal (always pointing away from the cone base), while the other two are proximal (always pointing toward the cone base). Up to five inverted winged seeds are present on the adaxial side of the ovuliferous scales. A systematic review of Late Paleozoic to Early Cretaceous multilobed ovuliferous scales—together with a morphological cladistic analysis—supports the placement of the Mongolian material in a new genus within the voltzian clade of the Voltziales. Conclusions. Krassilovia mongolica provides evidence of the additional diversity of extinct voltzian conifers and shows that some persisted to inhabit forest-moor swamp environments in eastern Asia during the Early Cretaceous. The new fossil taxon also shows novel morphological adaptations of the bract-scale complexes and the cone (i.e., imbrication and interlocking) for the protection of the ovules/seeds that are broadly concurrent with the appearance of new insect and other animal feeding strategies.

ABSTRACT Chrysichthys nigrodigitatus (Lacépède) specimens were sampled in the Sanaga River and in the Dibamba River. Three new species, Protoancylodiscoides edeaensis sp. nov., P. yombai sp. nov. from both rivers, and P. dibambaensis sp. nov. from the Dibamba River alone, are described. Protoancylodiscoides edeaensis sp. nov., close to P. mansourensis El-Naggar, 1987 and P. chrysichthes Paperna, 1969 by the morphology of the haptor sclerotised parts, differs from these species by the penis length and the morphology of the vagina. Protoancylodiscoides yombai sp. nov. is close to P. edeaensis sp. nov., P. mansourensis, and P. chrysichthes by the morphology of some sclerotised parts of the haptor (ventral bar, ventral anchors, dorsal onchium and hooks). However, it differs from these species by the morphology of the vagina, of the outer root of the dorsal anchor, and the size of some sclerotised parts (dorsal anchor total length, dorsal bar length, ventral anchor length, and penis length). Protoancylodiscoides dibambaensis sp. nov. is close to P. ivoiriensis Bouah, N’Douba & Pariselle, 2021 by the lack of the onchium and the morphology of some sclerotised parts of the haptor. However, it differs from this species by the morphology of the dorsal bar, penis length, dorsal bar length, and of the ventral anchor total length. This study on monogeneans raises the question of ichthyofauna exchange between adjacent streams; it also reveals a longitudinal gradient of Protoancylodiscoides species richness in the Sanaga River.

A catalogue of type specimens (holotypes, paratypes, lectotypes, and paralectotypes) of species of the family Xylomyidae (Diptera) described by Th. Pleske and N.P. Krivosheina and deposited in the collection of the Zoological Institute of the Russian Academy of Sciences in St. Petersburg, Russia is presented. Photographs of the specimens and labels of the holotypes and lectotype are given.

A catalog of the types (holotypes, paratypes, lectotypes, paralectotypes) of the species of the family Xylophagidae (Diptera), described by F.D. Pleske (Th. Pleske), N.P. Krivosheina and B.M. Mamaev, and also by V.G. Kovalev, which are stored in the collection of the Zoological Institute of the Russian Academy of Sciences in St. Petersburg, is presented. Photographs of the holotypes and lectotypes and of their labels are given.

The Eulert pliosaurid remains (FHSM VP-321) housed at the Sternberg Museum of Natural History (Kansas, U.S.A.) include one of the world's best examples of a Cretaceous pliosaurid plesiosaur skull. The specimen's original assignment to Brachauchenius lucasi was based solely upon the skull (dorsal surface) and left lower jaw (lateral view) because the specimen was embedded in a plaster mount. The history of B. lucasi is similarly problematic, because the type and a referred skull were formerly visible only in ventral and dorsal views, respectively. Further preparation and comparison of these specimens reveal new data about the arrangement of cranial elements. The Eulert pliosaurid bears several distinct autapomorphies as compared with B. Lucasi, including cranial proportions (pretemporal length of palate longer, shorter temporal fenestrae), configuration of skull roof elements (frontals participate in premaxilla-parietal suture, suture occurs further forward), and configuration of the palate (posterior vomers not masked by medial alar extensions of the palatines, caudal vomerian fenestrae positioned further posterior, long slit-like anterior pteryoid vacuity present). Furthermore, FHSM VP-321 possesses double-headed cervical ribs, a feature previously unknown in Cretaceous pliosaurids. This combination of characters merits separation of the Eulert pliosaurid and a referred specimen to a new taxon, Megacephalosauris eulerti. The type and paratype skulls of M. eulerti are 1.5 m and 1.75 m in length, respectively, and thus 50% and 75% larger than the known 1-m-long skulls of B. lucasi, suggesting that M. eulerti may attain larger size than B. lucasi.

With its short and pointed rostrum, the small fossil dolphin Brachydelphis mazeasi, from late middle to early late Miocene deposits of Chile and Peru, was originally described as an unusual member of the family Pontoporiidae (Cetacea, Odontoceti), presently only represented by the long-snouted Pontoporia blainvillei, a relict species from the eastern coast of South America. However, the phylogenetic relationships of Brachydelphis were debated in subsequent works. Based on a sample of well-preserved specimens from the late Miocene of the Pisco Formation (Tortonian, about 9 Ma) in the Sacaco Basin, southern coast of Peru, we describe a new species of Brachydelphis, B. jahuayensis, sp. nov. Also recorded in Chile, B. jahuayensis differs mostly from the type species in its considerably longer snout and higher tooth count. From a functional standpoint, the new species is interpreted as less specialized for suction feeding than the type species, relying more on its toothed jaws for prey capture. The inclusion of the long-snouted B. jahuayensis in future phylogenies will likely provide further support to the referral of Brachydelphis to the family Pontoporiidae. Finally, a review of the Mio-Pliocene vertebrate levels of the Pisco Formation in the Sacaco Basin clarifies the marine mammal content, succession, and stratigraphic correlation of each level, especially in the Aguada de Lomas locality. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Pseudoseisuropsis wintu sp. nov. is described from cranial material that had formerly been designated as a paratype of the extinct Pseudoseisuropsis nehuen. Thorough comparisons were made between the cranial specimens ascribed to Pseudoseisuropsis and many extant furnariid species. This new species is lower Pleistocene in age and increases the known diversity of Pseudoseisuropsis to three species. Cladistic analyses were performed using 43 cranial characters and a backbone constraint based on a well-supported phylogeny from a recent molecular analysis. In the most parsimonious tree, Pseudoseisuropsis was retrieved as a sister group of woodcreepers (Dendrocolaptinae) with low support. However, slightly suboptimal hypotheses, which could not be completely ruled out, suggest that this genus may be more closely related to other clades of Furnariidae. Hence, we agree with previous authors in regarding Pseudoseisuropsis as Furnariidae Incertae sedis. In addition, two fragmentary fossils ascribed to Pseudoseisuropsis were included in taxonomic comparisons: P. cuelloi, in order to assess the possibility that P. wintu sp. nov. belongs to that species, and another paratype of P. nehuen, to reassess its taxonomic identity.