Ancestral echinoderms from the Chengjiang deposits of China

  title={Ancestral echinoderms from the Chengjiang deposits of China},
  author={De-gan Shu and Simon Conway Morris and J W Han and Z.-F. Zhang and J.-N. Liu},
Deuterostomes are a remarkably diverse super-phylum, including not only the chordates (to which we belong) but groups as disparate as the echinoderms and the hemichordates. The phylogeny of deuterostomes is now achieving some degree of stability, especially on account of new molecular data, but this leaves as conjectural the appearance of extinct intermediate forms that would throw light on the sequence of evolutionary events leading to the extant groups. Such data can be supplied from the… 

The earliest history of the deuterostomes: the importance of the Chengjiang Fossil-Lagerstätte

The known diversity of Chengjiang deuterostomes are reviewed and it is argued that the vetulicolians and yunnanozoans represent very primitive deuterOSTomes, as well as new data to indicate that the yunncozoans are unlikely to be any sort of chordate.

Meiofaunal deuterostomes from the basal Cambrian of Shaanxi (China)

It is suggested that a key step in deuterostome evolution was the development of lateral openings that subsequently were co-opted as pharyngeal gills in Saccorhytus, which may help to explain the major gap between divergence times seen in the fossil record and estimates based on molecular clocks.

On the Phylum Vetulicolia

Since all vetulicolians share similar characters in their anterior section (pharynx), and on the basis of differences in their posterior section, a new classification system is proposed, with a new class, the Heteromorphida erected.

A stem-group cnidarian described from the mid-Cambrian of China and its significance for cnidarian evolution

Palaeontological data of extinct groups often sheds light on the evolutionary sequences leading to extant groups, but has failed to resolve the basal metazoan phylogeny including the origin of the


It is not possible on current evidence to reach an unequivocal conclusion regarding the phylogenetic position of the vetulicolians, but one possibility is that they are a sister group of arthropods that lost limbs but gained gill structures analogous to those of deuterostomes, but several features remain unexplained by this model.

The Fossil Record of the Cambrian “Explosion”: Resolving the Tree of Life1

In the last number of years, fossil discoveries from around the world, and particularly in China, have enabled the reconstruction of many of the deep branches within the invertebrate animal tree of

Saccorhytus is an early ecdysozoan and not the earliest deuterostome

The early history of deuterostomes, the group composed of the chordates, echinoderms and hemichordates1, is still controversial, not least because of a paucity of stem representatives of these

The first edrioasteroid echinoderm from the lower Cambrian Chengjiang biota of Yunnan Province, China

Until now, the earliest fossil echinoderms have been predominantly known from the early Cambrian of Laurentia and West Gondwana. Here, we describe Sprinkleoglobus extenuatus gen. et sp. nov. from the

Rare primitive deuterostomes from the Cambrian (Series 3) of Utah

Observations support an assignment of the banffiids to the vetulicolians, and the new taxon T. ignota represents the first discovery of a vetulicystid from beyond China and also significantly extends its stratigraphic range from Series 2 Cambrian into Series 3 Cambrian.

A New Species of Yunnanozoan with Implications for Deuterostome Evolution

A new species of Haikouella is described from the Chengjiang Lagerstätte with exceptional preservation of a number of features, which suggest that the origin of the pharyngeal clefts was independent of the gills and the diagnostic branchial arches of chordates may, therefore, be composite structures.

Primitive deuterostomes from the Chengjiang Lagerstätte (Lower Cambrian, China)

Several features of the Chengjiang fossil-Lagerstätte suggest that this group can throw light on an early stage of deuterostome diversification, and provide evidence for a new group of metazoans, the vetulicolians.

Reinterpretation of Yunnanozoon as the earliest known hemichordate

Yunnanozoon is reinterpreted here as the earliest known hemichordate, and its typical tripartite body plan is broadly consistent with that of living balanoglossid hemichor-dates (enteropneusts).

Hemichordates and deuterostome evolution: robust molecular phylogenetic support for a hemichordate + echinoderm clade

    Lindell D. BromhamB. Degnan
    Evolution & development
  • 1999
This approach provides the first statistically significant support for the hemichordate + echinoderm clade from molecular data, implying that the ancestral deuterostome had features that included an adult with a pharynx and a dorsal nerve cord and an indirectly developing dipleurula‐like larva.

The phylogenetic position of the pterobranch hemichordates based on 18S rDNA sequence data.

    K. Halanych
    Molecular phylogenetics and evolution
  • 1995
It is suggested that ciliated gill slits and the dorsal hollow nerve chord are pleisomorphic features of the Deuterostomia, the last common ancestor of the hemichordates and echinoderms.

An Early Cambrian tunicate from China

A probable tunicate Cheungkongella ancestralis from the Chengjiang fauna is reported that resembles the extant ascidian tunicate genus Styela whose morphology could be useful in understanding the origin of the vertebrates.

Vetulicolians--are they deuterostomes? chordates?

    T. Lacalli
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2002
This report summarizes the fossil evidence for the reinterprets of Vetulicola and related forms as basal deuterostomes and evaluates a possible alternative, that vetulicolians may instead be tunicate-like chordates.

A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China

Abstract  The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite

Are homalozoans echinoderms? An answer from the extraxial-axial theory

The Extraxial-Axial Theory (EAT) identifies body-wall homologies, common ontogenetic patterns, and major events in bodyplan evolution and strongly suggests that the bizarre asymmetry of homalozoans is a derived characteristic, and not indicative of plesiomorphic morphology for either chordates or echinoderms.

A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China

The genus and species Yuyuanozoon magnificissimi, a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China, showing the general characteristics of Ventulicolia, but the exclusive "atrial cavity" and external gill observed indicate that the new form is different from those previously described.