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The family Inversiulidae, and its only genus Inversiula, are unique among cheilostome bryozoans owing to the reverse orientation of the operculum, which hinges distally instead of proximally. Inversiula currently includes four extant and one fossil species almost exclusively distributed in the Southern Hemisphere. A phylogenetic analysis of the Inversiulidae based on morphological characters was performed, showing the existence of two clades with contrasting development of the frontal shield. As a result of this analysis, Parainversiula gen. nov. is erected to contain inversiulid species with an umbonuloid frontal shield structure and fewer than 30 central spoked pores. Two poorly known fossil species from the early Miocene of Patagonia (Argentina), originally assigned to the genus Microporella, are here redescribed as Parainversiula sp. and P. chubutiana (Canu) comb. nov. The historical, time-calibrated biogeography of Inversiulidae was estimated using an event-based, multi-model quantitative analysis. The analyses estimated that Australasia was the ancestral area of Parainversiula and a dispersion of the genus into South America occurred between the late Eocene and Oligocene (c. 23–42 Ma), an event that could have been helped by the origin of the Antarctic Circumpolar Current. [ABSTRACT FROM AUTHOR]

Pelecanus paranensis sp. nov., a new pelican (Aves, Pelecanidae) from the marine Upper Miocene Paraná Formation, which crops out in the Province of Entre Ríos, Argentina, is described. This record constitutes the first report of a fossil pelican from Argentina and the southernmost from South America. The holotypical specimen consists of a very large and nearly complete pelvis, which is characterized by having the cristae iliacae dorsales continuous throughout its entire length and a large foramen acetabuli. The U-shaped morphology of the postacetabular section of the pelvis of the new species as well as the wide incisura sutura iliosynsacralis, allow to infer its phylogenetic position within the New World pelican species clade, showing a close relationship with the clade (P. occidentalis + P. thagus). A probable transAtlantic dispersal route for the ancestor of the New World pelicans is thus inferred. The inland Paranaense Sea, which flooded the South American Chaco-Paraná basin during the mid-Neogene, is proposed as a south-north pathway for ancestral forms of the clade (P. occidentalis + P. thagus). These regressive marine paleoenvironments of the Late Miocene may have acted as the evolutionary driver for the transition of pelican species from brackish or freshwater habitats to those inhabiting strictly marine coastlines. [ABSTRACT FROM AUTHOR]

Fossil remains of extinct mylodontine sloths have been discovered in numerous localities throughout the American supercontinent, but knowledge of them is still mainly centered on the Pleistocene forms rather than their Neogene relatives. In this contribution, previously unpublished cranial and postcranial materials herein ascribed to Glossotherium chapadmalense (Kraglievich), coming from the Pliocene Chapadmalal Formation (Province of Buenos Aires, Argentina), are presented. These remains are described and compared with those of other mylodontine species from South and North America, providing an exhaustive characterization of cranial morphology in G. chapadmalense and some preliminary insights into its postcranial anatomy. The results have revealed a unique combination of differences and similarities of this enigmatic species with the larger-sized representatives of Glossotherium. In addition, these materials allowed shedding light on the long-standing uncertainties regarding its taxonomic status, as this form has been alternately considered to belong to the genera Glossotherium or Glossotheridium over the last century. As a result, the genus Glossotherium was present, at least, at the Early–Late Pliocene transition in the Pampean region of Argentina, and is recorded by the Upper Pleistocene throughout the entire South American continent. The radiation of the Pleistocene species is associated with a consistent body mass increase that was probably a response to the cooling temperatures and higher predation pressure in South America during the Late Pliocene–Early Pleistocene. These phenomena were probably driven by the stable emergence of the Panamanian Isthmus around 3 Ma and the successive faunal turnover pulses of the Great American Biotic Interchange. [ABSTRACT FROM AUTHOR]

The cheilostome bryozoan genus Taylorius Gordon, 2014 comprises six named living and fossil species from New Zealand and one Recent species from South Africa. Taylorus nom. nov. is proposed as a replacement name for Taylorius Gordon, 2014 (Bryozoa), a secondary homonym of Taylorius Britton, 1960 (Arthropoda: Coleoptera). Here, we describe Taylorus patagonicus sp. nov. from the early Miocene of Argentine Patagonia, and two new living species from New Zealand, Taylorus microperforatus sp. nov. and Taylorus alatus sp. nov. These new finds extend the known range of Taylorus nom. nov. to areas formerly comprising the Gondwanan supercontinent. Cladistic analysis suggests that there is a basal divergence within Taylorus nom. nov. in which an extant lineage consisting of species from South Africa and New Zealand is the sister group to the remaining species. Two New Zealand fossil taxa, T. masoni and T. waiparaensis, were not recovered in an exclusively Zealandian clade. The early Miocene New Zealand species T. masoni nested with three Recent Zealandian species, this subclade being sister to a group comprising the remaining New Zealand species and that from Patagonia. These different lineages suggest that Taylorus nom. nov. originated in the Paleogene, perhaps in the early Oligocene or late Eocene. [ABSTRACT FROM AUTHOR]