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Sunday, May 8th, 2022
| Time | Event | ||||
| 1:29p | [Ichthyology • 2022] Biogeographic Reconstruction of the Migratory Neotropical Fish Family Prochilodontidae (Teleostei: Characiformes)
Abstract Geographically, widespread Neotropical fish lineages offer opportunities to reconstruct historical biogeography patterns and infer processes leading to modern ichthyological diversity and distribution. The characiform family Prochilodontidae is well suited for such reconstruction because their migrations limit population substructure within river systems. Therefore, their biogeographic history should match closely the history of connectivity among Neotropical river basins. Here, we combine a time-calibrated phylogeny with biogeographic model testing to recover the history of this family's diversification. Results support the Miocene rise of the Andean Eastern Cordillera as a dispersal barrier, but also indicate a much earlier Eocene origin of the trans-Andean genus Ichthyoelephas. Despite the early origin of the family and its three constituent genera, most prochilodontid lineages originated during the Miocene in Greater Amazonia, likely due to drainage reorganizations caused by Andean uplift. Subsequent speciation appears linked to interbasin exchanges and expansions of Amazonian lineages into Brazilian coastal systems. The modern richness of Prochilodus in easterly drainages appears to be relatively young, with only Prochilodus vimboides likely reaching that region prior to the late Miocene. The rise of the Vaupes Arch coincides with two splits between Orinocoan and Amazonian lineages circa 9 million years ago (Ma). However, two instances of later dispersal between these drainages reveal the permeability of the Vaupes Arch, suggesting that it may promote periodic speciation. This study illustrates how model-based biogeographic studies of widespread groups can reconstruct historic paths of dispersal and help reveal how landscape evolution promoted modern diversity patterns. Keywords: Amazon, BioGeoBEARS, Eastern Cordillera, historical biogeography, Ostariophysi
 Benjamin W. Frable, Bruno F. Melo, João P. Fontenelle, Claudio Oliveira and Brian L. Sidlauskas. 2022. Biogeographic Reconstruction of the Migratory Neotropical Fish Family Prochilodontidae (Teleostei: Characiformes). Zoologica Scripta. DOI: 10.1111/zsc.12531  | ||||
| 1:29p | [Mollusca • 2022] Solaropsis caperata • A New Species of Solaropsis (Gastropoda: Solaropsidae) from Amapá , Brazil triggering uncertainty about the Genus and Redefinition of Some Species
ABSTRACT An attempt to analyse the taxonomy of the genus Solaropsis, aiming to allocate a new species collected in Rio Cajari Extractive Reserve, Laranjal do Jari, Amapá State, Brazil, revealed that a nebula of uncertainties surrounds the genus, from the family level to the validity of several species. An initial taxonomic treatment is given for some taxa herein, resulting in modifications such as S. pellisserpentis (Gmelin, 1791) as an objective synonym of S. undata ([Lightfoot], 1786); and S. cicatricata (Beck, 1853) as the oldest name of the depression-bearing species. This taxonomic treatment is intended only to allow the description of the new species. Solaropsis caperata is, thus, introduced, having as its main distinguishing features the globose shell, strongly depressed half a whorl before the peristome, slightly convex whorls, large aperture and umbilicus, and cream colour with brown spots.  Solaropsis caperata Fernanda S. Silva, Raimundo N.G. Mendes-Júnior and Luiz Ricardo L. Simone. 2022. A New Species of Solaropsis from Amapá , Brazil (Gastropoda: Solaropsidae) triggering uncertainty about the Genus and Redefinition of Some Species. Journal of Natural History. 56(1-4); 79-89. DOI: 10.1080/00222933.2022.2033333 | ||||
| 2:42p | [PaleoBotany • 2022] Pandanus estellae (Pandanaceae) • A Fossil Syncarpous Fruit from Australia Provides Support for a Gondwanan History for the Screw Pines
Abstract Premise of research. The Capella region in central Queensland has yielded diverse, three-dimensionally preserved, permineralized floras that are associated with 32–28 Ma Cenozoic volcanics. A new fossil infructescence that was recently discovered from a new locality is shown to have affinities with Pandanus Parkinson, and it is described herein as Pandanus estellae sp. nov. Methodology. The affinities of the material were assessed according to a literature review of families that have syncarpous fruits or cones. The specimen was studied and photographed using conventional macromorphological approaches. Micro–computed tomography scanning was used to ascertain whether the internal structure of the fruit was preserved. Pivotal results. The single infructescence consists of several basally connate segments that lack a clear phyllotactic pattern and are variable in size and shape; the external surface of each segment is irregularly pentagonal-hexagonal and strongly coalescent. Each segment is interpreted as multicarpellate. Collectively, these features allow interpretation of the fossil as syncarpous, and the morphological features support placement in the monocot family Pandanaceae. The arrangement of segments is consistent with the polydrupes that characterize most species of Pandanus, but the small size of the infructescence of P. estellae differs from fruits of modern species in the genus, which are typically much larger. The anatomy of P. estellae is not preserved. The inferred Early Oligocene age for the fossil fruit predates current estimates, which are based on molecular data and limited calibration points, by about 8–10 Myr for the split of Benstonea Callm. and Buerki from Pandanus. Conclusions. The new species P. estellae is significant because it provides credible pre-Pleistocene evidence of the genus and is the oldest unequivocal fruit of Pandanus currently known. Its occurrence in Australia supports a Gondwanan history for the family.  Pandanus estellae sp. nov. Andrew C. Rozefelds, Paula J. Rudall, Matt C. Herne, Anita K. Milroy and Joe Bridgeman. 2022. A Fossil Syncarpous Fruit from Australia Provides Support for a Gondwanan History for the Screw Pines (Pandanus, Pandanaceae). International Journal of Plant Sciences. 183(4); DOI: 10.1086/719431 |
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