| Autor: |
Randle, Emma, Sansom, Robert |
| Jazyk: |
angličtina |
| Rok vydání: |
2017 |
| Předmět: |
|
| Zdroj: |
Randle, E & Sansom, R 2017, ' Phylogenetic relationships of the ‘higher heterostracans’ (Heterostraci: Pteraspidiformes & Cyathaspididae), extinct jawless vertebrates. ', Zoological Journal of the Linnean Society . https://doi.org/10.1093/zoolinnean/zlx025 |
| Popis: |
Heterostracans are a clade of extinct jawless fishes that were a largecomponent of early vertebrate ecosystems. They are key members of thegnathostome stem, and as such they, are central to our interpretation andunderstanding of early vertebrate evolution. Our knowledge ofheterostracan inter-relationships is incomplete, with previous phylogeneticanalyses focusing on the intra-relationships of individual clades. The twolargest clades of heterostracans, Cyathaspididae and Pteraspidiformes,comprise Janvier’s ‘higher heterostracans’ and have been interpreted asmonophyletic sister groups. Here we present a new parsimony basedphylogeny for the Pteraspidiformes and Cyathaspididae includingquantitative data. Our results indicate the Cyathaspididae are aparaphyletic assemblage with respect to a monophyletic Pteraspidiformes(which includes the Psammosteidae). Furthermore, we show theAnchipteraspididae are sister group to the Pteraspidiformes, when usingpteraspid-type bauplan to interpret their anatomy. Application ofstratigraphic range data and congruence measures was used to assess theperformance of different treatments of phylogenetic data in terms ofstratigraphic consistency; equal weighting of quantitative and qualitativecharacters was found to consistently outperform implied weighting. Ourcombined results indicate that inclusion of quantitative characters cangreatly improve resolution of ostracoderm phylogenies and provides aframework to consider the intra- and inter-relationships of heterostracansmore broadly. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
