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… 

Origins and early evolution of arthropods

With respect to the interrelationships of the three extant clades of Panarthropoda, a sister group relationship between Onychophora and Arthropoda is endorsed by transcriptomics and microRNAs, although this hypothesis forces homoplasy in characters of the segmental ganglia that are shared by tardigrades and arthropods.

The morphology and phylogenetic position of the Cambrian lobopodian Diania cactiformis

This study challenges the previous description of anteroposterior orientation, terminal claws and trunk tagmosis as expressed by differentiated anterior and posterior appendages in Cambrian lobopodians, and revisits the phylogeny of stem arthropods.

The early history of the metazoa—a paleontologist’s viewpoint

  • A. Zhuravlev
  • Geography, Environmental Science
    Biology Bulletin Reviews
  • 2015
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.

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.

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.

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.

The evolution of biramous appendages revealed by a carapace-bearing Cambrian arthropod

A new arthropod, Erratus sperare gen. et sp.



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.

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.

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.

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 for


  • P. Goloboff
  • Computer Science
    Cladistics : the international journal of the Willi Hennig Society
  • 1993
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 searching

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.

Phylogenetic Analysis Using Parsimony (*and Other Methods) Version

  • 2002