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Tuesday, November 16th, 2021
| Time | Event | ||||||
| 8:17a | [Botany • 2020] Utricularia kamarudeenii (Lentibulariaceae) • A New Species from Kerala, India
Abstract A new species of Utricularia named U. kamarudeenii, from the paddy fields of Kottayam district of Kerala, India, is described and illustrated. The new species resembles U. aurea but differs from it in the length of spur with respect to lower lip, deeply bilobed lower lip, presence of one type of trap having basal mouth without appendages and hexagonal shape of the seed. Keywords: bladderwort, insectivorous plant, Lamiales, stolons, Eudicots    Sindhu Arya, Reshma Raju, Parappurakkal Thazhe Arunraj, Walsan Kalarikkal Vishnu, Punnakot Biju and Venugopalan Nair Saradhamma Anilkumar. 2020. Utricularia kamarudeenii (Lentibulariaceae): A New Species from Kerala, India. Phytotaxa. 447(1); 68–72. DOI: 10.11646/phytotaxa.447.1.7 | ||||||
| 2:45p | [Ichthyology • 2021] Molecular Phylogeny and Phylogeography of the Freshwater Fish Genus Pethia (Cypriniformes: Cyprinidae) in Sri Lanka
Abstract Background: Sri Lanka is a continental island separated from India by the Palk Strait, a shallow-shelf sea, which was emergent during periods of lowered sea level. Its biodiversity is concentrated in its perhumid south-western ‘wet zone’. The island’s freshwater fishes are dominated by the Cyprinidae, characterized by small diversifications of species derived from dispersals from India. These include five diminutive, endemic species of Pethia (P. bandula, P. cumingii, P. melanomaculata, P. nigrofasciata, P. reval), whose evolutionary history remains poorly understood. Here, based on comprehensive geographic sampling, we explore the phylogeny, phylogeography and morphological diversity of the genus in Sri Lanka. Results: The phylogenetic analyses, based on mitochondrial and nuclear loci, recover Sri Lankan Pethia as polyphyletic. The reciprocal monophyly of P. bandula and P. nigrofasciata, and P. cumingii and P. reval, is not supported. Pethia nigrofasciata, P. cumingii, and P. reval show strong phylogeographic structure in the wet zone, compared with P. melanomaculata, which ranges across the dry and intermediate zones. Translocated populations of P. nigrofasciata and P. reval in the Central Hills likely originate from multiple sources. Morphological analyses reveal populations of P. nigrofasciata proximal to P. bandula, a narrow-range endemic, to have a mix of characters between the two species. Similarly, populations of P. cumingii in the Kalu basin possess orange fins, a state between the red-finned P. reval from Kelani to Deduru and yellow-finned P. cumingii from Bentara to Gin basins. Conclusions: Polyphyly in Sri Lankan Pethia suggests two or three colonizations from mainland India. Strong phylogeographic structure in P. nigrofasciata, P. cumingii and P. reval, compared with P. melanomaculata, supports a model wherein the topographically complex wet zone harbors greater genetic diversity than the topographically uniform dry-zone. Mixed morphological characters between P. bandula and P. nigrofasciata, and P. cumingii and P. reval, and their unresolved phylogenies, may suggest recent speciation scenarios with incomplete lineage sorting, or hybridization. Keywords: Smiliogastrinae, Morphology, Barb, Biodiversity hotspot, India        Conclusions: Despite Pethia being a widespread freshwater fish genus in South Asia, most studies so far have focused on taxonomy, with little or no emphasis on geographic sampling focusing on phylogeographic work. We focus on phylogeny, phylogeography, using nuclear DNA and mitochondrial DNA markers, and compare these results with morphology of the group. Polyphyly in Sri Lankan Pethia suggests two or three colonizations from mainland India. Strong phylogeographic structure suggests that the topographically complex wet zone harbors greater genetic diversity than the more uniform dry-zone. Mixed morphological characters between some of the taxa, and their unresolved phylogenies, may suggest recent speciation events with incomplete lineage sorting, or hybridization. The knowledge generated will not only form a foundation for systematics work, but also will help in understanding the processes of speciation and patterns of distribution, allowing for informed conservation of this charismatic group of fishes.  Hiranya Sudasinghe, Tharindu Ranasinghe, Jayampathi Herath, Kumudu Wijesooriya, Rohan Pethiyagoda, Lukas Rüber and Madhava Meegaskumbura. 2021. Molecular Phylogeny and Phylogeography of the Freshwater-fish Genus Pethia (Teleostei: Cyprinidae) in Sri Lanka. BMC Ecology and Evolution. 21: 203. DOI: 10.1186/s12862-021-01923-5 | ||||||
| 2:45p | [Paleontology • 2021] Lihuacaris ferox & Alacaris? • New Multipodomerous Appendages of Stem-group Euarthropods from the Cambrian (Stage 4) Guanshan Konservat-Lagerstätte, eastern Yunnan, China
Abstract Stem-group euarthropods are important for understanding the early evolutionary and ecological history of the most species-rich animal phylum on Earth. Of particular interest are fossil taxa that occupy a phylogenetic position immediately crownwards of radiodonts, for this part of the euarthropod tree is associated with the appearance of several morphological features that characterize extant members of the group. Here, we report two new euarthropods from the Cambrian Stage 4 Guanshan Biota of South China. The fuxianhuiid Alacaris? sp. is represented by isolated appendages composed of a gnathobasic protopodite and an endite-bearing endopod of at least 20 podomeres. This material represents the youngest occurrence of the family Chengjiangocarididae, and its first record outside the Chengjiang and Xiaoshiba biotas. We also describe Lihuacaris ferox gen. et sp. nov. based on well-preserved and robust isolated appendages. Lihuacaris ferox exhibits an atypical combination of characters including an enlarged rectangular base, 11 endite-bearing podomeres and a hypertrophied distal element bearing 8–10 curved spines. Alacaris? sp. appendages display adaptations for macrophagy. Lihuacaris ferox appendages resemble the frontal appendages of radiodonts, as well as the post-oral endopods of chengjiangocaridid fuxianhuids and other deuteropods with well-documented raptorial/predatory habits. Lihuacaris ferox contributes towards the record of endemic biodiversity in the Guanshan Biota. Keywords: Deuteropoda, Euarthropoda, Fuxianhuiida, Lihuacaris ferox, Radiodonta, Chengjiango, carididae
Systematic palaeontology SUPERPHYLUM Panarthropoda Nielsen [1995] ORDER Fuxianhuiida Bousfield [1995] FAMILY Chengjiangocarididae Hou and Bergström [1997] Type genus. Chengjiangocaris Hou & Bergström [1991] Other genera included. Alacaris Yang, Ortega-Hernández, Legg, Lan, Hou & Zhang [2018] Alacaris Yang, Ortega-Hernández, Legg, Lan, Hou & Zhang [2018] Alacaris? sp. .... 
Incertae sedis GENUS Lihuacaris gen. nov. Type species. Lihuacaris ferox gen. et sp. nov. Diagnosis. Arthropodized elongate appendage composed of a rectangular base, proximal relative to 11 tall rectangular podomeres and a long subtriangular distal element; podomeres increase in length distally, alternate with triangular articulating membranes and bear small triangular endites (one pair per podomere) that insert at the midpoint of ventral margin; distal element bears 8–10 robust curved ventral spines that increase in size towards the distal end of the appendage. Etymology. Concatenation of the first part of the name of the section where the fossils were found (Lihuazhuang), and the Latin ‘caris’ (or Greek ‘καρις’), meaning ‘crab’ or ‘shrimp’, a suffix commonly used for euarthropods. Type material. Holotype: YKLP 12438 (figure 6), a complete appendage preserved as a lateral compression; Paratype: YKLP 12439 (figure 7a), an incomplete appendage missing the base and proximalmost six podomeres, preserved as a lateral compression. Additional material. Four partial specimens YKLP 12440–12443 (figure 7b–e). Type locality and horizon: Lihuazhuang section, locality ca 2.5 km southeast of the Lihuazhuang village (figure 2). Lower part of Wulongqing Formation, Cambrian Stage 4, Palaeolenus biozone [Hu, et al., 2010]. Lihuacaris ferox sp. nov. Etymology. From ferox (Latin = ferocious) in reference to the inferred predatory habits of this animal.   Conclusion: The endemic taxa Alacaris? sp. and Lihuacaris ferox increase the known diversity of euarthropods in the Guanshan Biota. Alacaris? sp., the second fuxianhuiid reported from this exceptional biota, represents both the first occurrence of the Chengjiangocarididae in these beds and the youngest record of this fuxianhuiid family to date. The exact affinities of the new taxon Lihuacaris ferox are uncertain, but it most likely falls close to radiodonts in the euarthropod stem-lineage, or possibly fuxianhuiids as early members of Deuteropoda. Additional material of Lihuacaris ferox is critical for clarification of its relationships with other stem-group euarthropods and may potentially inform on the sequence of evolution of fundamental euarthropod characters. Appendages of Lihuacaris ferox appear adapted for capturing non-biomineralized prey. This allows predatory habits to be inferred for this enigmatic taxon and suggests that radiodonts were not the only large predators in the Guanshan Biota. The appendages of Alacaris? sp. feature gnathobasic protopodite indicative of macrophagous feeding habits. The endemism of all these taxa probably reflects the relatively proximal shelf depositional settings of the Guanshan Konservat-Lagerstätte [Jiao, et al., 2021]. De-Guang Jiao, Stephen Pates, Rudy Lerosey-Aubri, Javier Ortega-Hernández, Jie Yang, Tian Lan and Xi-guang Zhang. 2021. New Multipodomerous Appendages of Stem-group Euarthropods from the Cambrian (Stage 4) Guanshan Konservat-Lagerstätte. Royal Society Open Science. DOI: 10.1098/rsos.211134 |
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