Phylogenetic position of Diania challenged

  title={Phylogenetic position of Diania challenged},
  author={R. Mounce and Matthew Albion Wills},
Arising from J. Liu et al. 470, 526–530 (2011)10.1038/nature09704; Liu et al. replyLiu et al. describe a new and remarkable fossil, Diania cactiformis. This animal apparently combined the soft trunk of lobopodians (a group including the extant velvet worms in addition to many Palaeozoic genera) with the jointed limbs that typify arthropods. They go on to promote Diania as the immediate sister group to the arthropods, and conjecture that sclerotized and jointed limbs may therefore have evolved… Expand
The morphology and phylogenetic position of the Cambrian lobopodian Diania cactiformis
New observations on D. cactiformis are made using newly collected material, rejecting the evidence for sclerotized, segmented and articulated appendages; instead the appendages compare more closely to lobopods. Expand
Origins and early evolution of arthropods
Phylogenomics reconstructs an arthropod tree in which a monophyletic Arthropoda splits into Pycnogonida +-Euchelicerata and Myriapoda + Pancrustacea, and a sister group relationship between Onychophora and Arthropod is endorsed by transcriptomics and microRNAs. Expand
The early history of the metazoa—a paleontologist’s viewpoint
In the aggregate, modern data from molecular biology, palaeontology, and comparative embryology/morphology, having been revitalized by the introduction of new microscopy techniques, imply that the hypothesized planktotrophic gastrae-like common ancestor is the least likely of the diverse suggestions on the origins of the Metazoa. Expand
Cambrian lobopodians: A review of recent progress in our understanding of their morphology and evolution
The legs of Aysheaia pedunculata have a strong attachment with the body, like those of lobopodians in the Chengjiang Fauna, anditudinal wrinkles on the body of Xenusion auerswalde are regarded here as putative muscles. Expand
A Tube-Dwelling Early Cambrian Lobopodian
Comprehensive phylogenetic analyses using parsimony, Bayesian inference, and maximum likelihood all support Facivermis as a luolishaniid in a derived position within the onychophoran stem group rather than as a basal panarthropod, and conclude that Faciver Mis provides a rare early Cambrian example of secondary loss to accommodate a highly specialized tube-dwelling lifestyle. Expand
Decay of velvet worms (Onychophora), and bias in the fossil record of lobopodians
It is hypothesized that stemward slippage is unlikely to be a significant factor among the taphonomic biases that have affected organisms where decay-resistant features of the anatomy are rich in phylogenetically informative characters, and organisms which possess decay- resistant body parts but have informative characters concentrated in decay-prone tissues will be just as liable to bias as those that lack decay- resisting body parts. Expand
Worm-lobopodian assemblages from the Early Cambrian Chengjiang biota: Insight into the “pre-arthropodan ecology”?
It is hypothesized that during a time interval preceding Cambrian Stage 2, scalidophoran worms and lobopodians were the prevalent ecdysozoan component of early animal communities, and the notion of a possible “pre-arthropodan ecology” is introduced. Expand
The disparity of priapulid, archaeopriapulid and palaeoscolecid worms in the light of new data
This study samples at the species level and includes numerous fossils and some extant forms described in the last fifteen years of Priapulids, among the first groups used to test hypotheses concerning the morphological disparity of Cambrian fossils relative to the extant fauna. Expand
Pandora’s Pithos
An epidemic of Cambrian Explosion (CE) virus, a “phylagen” that was able to infect and reconfigure metazoan morphogenetic fields and genomic kernels, caused the geologically simultaneous appearance of numerous animal phyla at the base of the Cambrian. Expand
Deconstructing the long‐standing a priori assumption that serial homology generally involves ancestral similarity followed by anatomical divergence
It is shown that: (a) there are almost never cases of true ancestral similarity; (b) in evolution, such structures— for example, vertebra—and/or their subparts—for example, “transverse processes”—many times display trends toward less similarity while in many others display trends towards more similarity, that is, one cannot say that there is a clear, overall trend to anisomerism. Expand


Morphology of Luolishania longicruris (Lower Cambrian, Chengjiang Lagerstätte, SW China) and the phylogenetic relationships within lobopodians.
A new cladistic analysis suggests that fossil lobopodians are paraphyletic or even polyphyletic and L. longicruris may be an important representative of the stem lineage leading to arthropods. Expand
An armoured Cambrian lobopodian from China with arthropod-like appendages
D. cactiformis is described as an ‘armoured’ lobopodian from the Chengjiang fossil Lagerstätte (Cambrian Stage 3), Yunnan, southwestern China, remarkable for possessing robust and probably sclerotized appendages, with what appear to be articulated elements. Expand
The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution
Hurdia possesses a general body architecture similar to those of Anomalocaris and Laggania, but differs from those anomalocaridids by possessing a prominent anterior carapace structure, and provides insight into the origins of important arthropod features, such as the head shield and respiratory exites. Expand
The nature and significance of the appendages of Opabinia from the Middle Cambrian Burgess Shale
A new hypothesis for the origin of the arthropod biramous limb from an exopod like that in Opabinia is presented, which involves an endite-bearing phyllopodous limb as an intermediate stage. Expand
Probability, parsimony, and Popper
ture (Archie, 1989a, 1989b; Faith, 1990; Faith and Cranston, 1991) compare the mini? mum length of the tree found for the orig? inal character data to the length of the tree achieved forExpand
Abstract— A new method for weighting characters according to their homoplasy is proposed; the method is non‐iterative and does not require independent estimations of weights. It is based on searchingExpand
TNT, a free program for cladistic analysis
  • Cladistics 24,
  • 2008
Lobopodian phylogeny reanalysed
An cladistic analysis resolved Diania as sister-taxon to arthropods and tentatively inferred that arthropodization may have preceded arthrodization (sclerotization of body elements) inArthropod evolution, which concur with the reasoning behind this inference, but rests on a phylogenetic placement that does not reproduce. Expand
Phylogeny of Diania challenged
  • Nature
  • 2011