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The Phylogeny of Antiarch Placoderms Sarah Kearsley

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The Phylogeny of Antiarch Placoderms Sarah Kearsley It is a non-parametric Wilcoxon matched-pairs signed ranks test. The number of state changes each character goes through is re goes through of state changes each character The number matched-pairs signed ranks test. Wilcoxon It is a non-parametric of the same cla actually approximations cladograms are different not two apparently or test can determine whether Templeton The with a small test statistic indicating statistically significant result. then compared are The results Ts. test statistic, Wilcoxon absolute value is the The sum with the smaller summed separately. The ranks assigned to positive and negativ assigned a rank based on absolute value. are These scores as n. is recorded scores of no The number the scores. These numbers are tree. those of the other subtracted from are of changes in one tree The number relatives within placoderms are thought to be either the arthrodires or or the arthrodires thought to be either within placoderms are relatives Thei branches of jawed vertebrates. major to be members of the placodermi, one three generally considered are Antiarchs phylogeny of the placoderms. The cladogram to the left shows the relationship of placoderms to other vertebrates. of placoderms to other The cladogram to the left shows relationship phylogeny of the placoderms. considered to be closely related. These inferences have the potential to affect the topology of the resulting trees. To learn To trees. have the potential to affect topology of resulting These inferences to be closely related. considered taxa states from character Zhu sometimes inferred not at all preserved anatomy was poorly or the relevant In cases where observation. to date (Zhu, 1996) included information not derived from phylogenetic study of antiarchs The most comprehensive that inferring characters does not help the search for accurate phylogenies. for that inferring characters does not help the search res and different The false resolution to be generated. tree although they also caused a statistically significantly different of the results the robusticity found to increase characters were The inferred performed on both data sets. test were Templeton support indices, and the characters. Bootstrap analysis, Bremer matrix with and without inferred done on Zhu’s were trees most parsimoni for several tests have been performed. Heuristic searches characters have biased the results how these inferred Character 57 52 51 45 28 12 5 4 Difference in the number of state changes in the number Difference Echinoderms Lampreys Antiarch anatomy Antiarch Sharks pectoral armor are the only parts which are commonly preserved in the fossil record. in the fossil record. commonly preserved the only parts which are are pectoral armor the head, trunk, and this reason internal skeleton. For of mineralization than the scales or degree has a higher placoderms, the dermal armor As in other jointed pectoral appendages. and bony, long, boxlike thoracic armor their are The identifying characteristics of antiarchs Templeton test Templeton - Vertebrates -1 Placoderms 1 1 1 1 1 3 1 C: Lateral view of a reconstruction view B: Ventral A: Dorsal view The figure to the left is an anatomical diagram of The figure - Jawed Vertebrates - Jawed Bony Fish Background Land Vertebrates Abstract Romundina Arthrodira Rank Ptyctodontida The cladogram on the right shows Goujet's (1984) . -4 4 4 4 4 4 8 4 Petalicthyida - Placodermi approximations of the same cladogram approximations not are so the two trees Ts=4, In this case 5 to be significant with 95% confidence. equal to must be less than or Ts n=8, For Antiarcha Bothriolepis (Ritchie, 2002) Romundina Ts=4 n=8 Rhenanida The phylogeny of antiarch placoderms ult suggest if and e scores are are e scores to a table, . nzero nzero corded. , r closest r ous dogram. as adding assumptions to data. to be questioned. Looking at only a small subset of data may just as of antiarchs groups major monophyly of one the four this. In this case, the incomplete set of most parsimonious tr reflect and the newly generated tree between the published tree The d of most parsimonious trees. based on only a small fraction of the total number are Zhu's results Therefore, completion. was not allowe most parsimonious trees for The search as well. reason another for Zhu's published phylogeny should be rejected phylogenies. positively mi This has the potential to produce topology is significantly changed. supported by data. In some cases, the tree of structur matrix is a bad idea because the added assumptions may cause recovery Inferring characters in a taxon-character cladogram. resulting test demonstrates that it had a statistically significan Templeton the a loss of parsimony and potentially accuracy. r The added assumptions, however, result. robust and more resolved a more Zhu's matrix took less time to analyze, and produced Kujdanowiaspis Kujdanowiaspis Kujdanowiaspis Romundina Romundina Romundina Yunnanolepis Unnamed Antiarch Adams consensus trees Yunnanolepis Vanchienolepis Mizia Mizia Chuchinolepis Phymolepis Phymolepis Heteroyunnanolepis Zhanjilepis Zhanjilepis Zhanjilepis Heteroyunnanolepis Heteroyunnanolepis Yunnanolepis Tree with no inferred characters with no inferred Tree Chuchinolepis Chuchinolepis Mizia Unnamed Antiarch Minicrania based on Zhu's matrix Tree Phymolepis Xichonolepis Vanchienolepis Minicrania Grenfellaspis Minicrania Grenfellaspis Xichonolepis Zhu's published tree Sinolepis Sinolepis Dayaoshania Xichonolepis Liujiangolepis Grenfellaspis Dayaoshania Luquanolepis Sinolepis Liujiangolepis Sarah Kearsley Dianolepis Liujiangolepis Wudinolepis Jiangxilepis Luquanolepis Hohsienolepis Tenizolepis Nawagiaspis Microbrachius Briagalepis Gerdalepis Tenizolepis Monarolepis Wurungulepis Briagalepis Stegolepis Monarolepis Grossilepis Asterolepis Grossilepis Bothriolepis Pambulaspis Bothriolepis Wudinolepis Remigolepis Dianolepis Microbrachius Sherbonaspis Vietnamaspis Vietnamaspis Pterichthyodes Jiangxilepis Nawagiaspis Byssacanthus Luquanolepis Gerdalepis Kirgisolepis Nawagiaspis Pterichthyodes Hunanolepis Hunanolepis Dianolepis Byssacanthus Sherbonaspis Jiangxilepis Kirgisolepis Byssacanthus Tenizolepis Pterichthyodes Kirgisolepis Briagalepis Grossaspis Wurungulepis Monarolepis Lepadolepis Stegolepis Grossilepis Gerdalepis Asterolepis Bothriolepis Sherbonaspis Pambulaspis Wudinolepis Wurongulepis Remigolepis Hohsienolepis Stegolepis Microbranchius Asterolepis Hunanolepis Vietnamaspis Pambulaspis Vanchienolepis Remigolepis Conclusion clade which is only found when inferred characters are omitted. characters are clade which is only found when inferred traced on the cladograms. In this case, shape of plate diagnoses a can be The evolutionary changes of this character bone varies in antiarchs. The shape of this The M12 plate is a small bone in the pectoral appendage. Kujdanowiaspis Kujdanowiaspis Romundina Romundina Yunnanolepis Yunnanolepis Mizia Mizia Legend: Phymolepis Phymolepis this character. primitive state of This is the plate. short and wide M12 Remigolepis Zhanjilepis Zhanjilepis Heteroyunnanolepis Heteroyunnanolepis Tree with no inferred characters with no inferred Tree Chuchinolepis Chuchinolepis Unnamed Antiarch Minicrania based on Zhu's matrix Tree Vanchienolepis Xichonolepis Minicrania Grenfellaspis Xichonolepis M12 plate M12 plate short Sinolepis Dayaoshania has a Liujiangolepis Grenfellaspis Luquanolepis Sinolepis Dianolepis Liujiangolepis Jiangxilepis Luquanolepis Tenizolepis Nawagiaspis Briagalepis Gerdalepis Wurungulepis Monarolepis Stegolepis Grossilepis Asterolepis Bothriolepis Pambulaspis M12 plate long Wudinolepis Remigolepis Microbrachius Sherbonaspis Vietnamaspis Pterichthyodes Nawagiaspis Byssacanthus Gerdalepis Kirgisolepis Pterichthyodes Hunanolepis Sherbonaspis Dianolepis t effect on the Jiangxilepis character. state of this is the derived This M12 plate. a long and thin Bothriolepis Byssacanthus Equivocal sleading Tenizolepis ees caused the Kirgisolepis Wurungulepis Briagalepis ifferences ifferences Monarolepis misleading Stegolepis Grossilepis d to run Asterolepis e not Bothriolepis esulted in Pambulaspis Wudinolepis Remigolepis Hohsienolepis Hunanolepis Microbranchius has Vanchienolepis Vietnamaspis National d'Histoire Naturelle d'Histoire National China. Yunnan, Qujing, from antiarchs Antiarcha The phylogeny of the Zhu, M. 1996. (Placodermi, Pisces), with the description of Early Devonian slide_show.htm http://www.amonline.net.au/palaeontology/field_sites/ A. 2002. Palaeontology - Canowindra slide show. Ritchie, 211-243 107: Wales Proceedings of the Linnean Society New South a new Goujet, D. 1984. Placoderm interrelationships: of placoderm classifications. with a short review interpretation numbers greater than 1.0 are shown to the right of node. than 1.0 are numbers greater support dot. Bremer marked with a red than 70% are greater nodes with bootstrap percentages In the cladograms below, tree. support than the same nodes in other bremer have a higher based on Zhu's matrix but some nodes in the tree significantly, do not differ the two trees In this case, bootstrap values for bootstrap value of 70% is accurate with 95% confidence. clade with a A values can also show the accuracy of clades. denote well supported clades. Bootstrap bootstrap percentages support numbers and supported by the data. Large Bremer phylogenies are to which the recovered indicate the degree both support indices and bootstrap percentages The Bremer Kujdanowiaspis Kujdanowiaspis Romundina Romundina Yunnanolepis Yunnanolepis Mizia Mizia and bootstrap
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