Refine
Document Type
- Article (1)
- Part of Periodical (1)
Language
- English (2)
Has Fulltext
- yes (2)
Is part of the Bibliography
- no (2)
Keywords
- Brachiopoda (1)
- Brachiozoa (1)
- Bryozoa (1)
- Camaenidae (1)
- Compositional bias (1)
- Ectoprocta (1)
- Indonesia (1)
- Java (1)
- Kryptrochozoa (1)
- Landouria (1)
Institute
Background: Within the complex metazoan phylogeny, the relationships of the three lophophorate lineages, ectoprocts, brachiopods and phoronids, are particularly elusive. To shed further light on this issue, we present phylogenomic analyses of 196 genes from 58 bilaterian taxa, paying particular attention to the influence of compositional heterogeneity.
Results: The phylogenetic analyses strongly support the monophyly of Lophophorata and a sister-group relationship between Ectoprocta and Phoronida. Our results contrast previous findings based on rDNA sequences and phylogenomic datasets which supported monophyletic Polyzoa (= Bryozoa sensu lato) including Ectoprocta, Entoprocta and Cycliophora, Brachiozoa including Brachiopoda and Phoronida as well as Kryptrochozoa including Brachiopoda, Phoronida and Nemertea, thus rendering Lophophorata polyphyletic. Our attempts to identify the causes for the conflicting results revealed that Polyzoa, Brachiozoa and Kryptrochozoa are supported by character subsets with deviating amino acid compositions, whereas there is no indication for compositional heterogeneity in the character subsets supporting the monophyly of Lophophorata.
Conclusion: Our results indicate that the support for Polyzoa, Brachiozoa and Kryptrochozoa gathered so far is likely an artifact caused by compositional bias. The monophyly of Lophophorata implies that the horseshoe-shaped mesosomal lophophore, the tentacular feeding apparatus of ectoprocts, phoronids and brachiopods is, indeed, a synapomorphy of the lophophorate lineages. The same may apply to radial cleavage. However, among phoronids also spiral cleavage is known. This suggests that the cleavage pattern is highly plastic and has changed several times within lophophorates. The sister group relationship of ectoprocts and phoronids is in accordance with the interpretation of the eversion of a ventral invagination at the beginning of metamorphosis as a common derived feature of these taxa.
Revision of the land snail genus Landouria Godwin-Austen, 1918
(Gastropoda, Camaenidae) from Java
(2019)
A revision of the land snail genus Landouria Godwin-Austin, 1918 (Camaenidae) from Java reveals that this group represents the most diverse land snail radiation on that island. Only six species of Landouria were recognized from Java in the last revision of the genus based on shell characters. Our investigation, which also considers the genitalia as well as DNA sequences, shows that the diversity in Java is much higher. Based on newly collected specimens as well as museum material, twenty-eight species of Landouria from Java are described and figured. To stabilize the nomenclature, neotypes are designated for L. winteriana (Pfeiffer, 1842) and L. rotatoria (Pfeiffer, 1842). Sixteen species are described as new to science, i.e., L. naggsi sp. nov., L. parahyangensis sp. nov., L. nusakambangensis sp. nov., L. petrukensis sp. nov., L. tholiformis sp. nov., L. madurensis sp. nov., L. abdidalem sp. nov., L. sewuensis sp. nov., L. tonywhitteni sp. nov., L. sukoliloensis sp. nov., L. nodifera sp. nov., L. pacitanensis sp. nov., L. zonifera sp. nov., L. pakidulan sp. nov., L. dharmai sp. nov. and L. menorehensis sp. nov. Landouria conoidea (Leschke, 1914) comb. nov., L. intumescens (Martens, 1867) comb. nov., L. moussoniana (Martens, 1867) comb. nov., L. schepmani (Möllendorff, 1897) comb. nov. and L. leucochila (Gude, 1905) comb. nov. are considered valid species of the genus Landouria for the first time. Plectotropis kraepelini Leschke, 1914 syn. nov. is considered a probable synonym of L. winteriana (Pfeiffer, 1842), P. trichotrochium Möllendorff, 1897 syn. nov. is a synonym of L. epiplatia (Möllendorff, 1897) and the preoccupied name Helix squamulosa Martens, 1867 syn. nov. is a synonym of L. madurensis sp. nov. We estimate that there are actually more than fifty species of Landouria in Java because many shell samples could not be classified and because no material is available from several regions of the island. A molecular phylogeny reveals that the species from Java do not form a monophyletic group, but that at least one species from Timor is nested within Javanese clades. This means that the Oriental Landouria crossed Wallace's line, the supposed border between the Oriental and Australo-Papuan regions, at least twice and supports the conclusion that Wallace's line does not represent a more severe barrier for terrestrial organisms than other straits through the archipelago. Within the Javanese clades, species from western and eastern Java are mixed, indicating frequent dispersals also within Java.