Repository logo
 

New reconstruction of the Wiwaxia scleritome, with data from Chengjiang juveniles.


Loading...
Thumbnail Image

Type

Article

Change log

Authors

Zhang, Zhifei 
Smith, Martin R 
Shu, Degan 

Abstract

Wiwaxiids are a problematic group of scale-covered lophotrochozoans known from Cambrian Stages 3-5. Their imbricating dorsal scleritome of leaf-like scales has prompted comparison with various annelids and molluscs, and has been used as a template to reconstruct the articulation pattern of isolated Small Shelly Fossils. The first articulated specimens of Wiwaxia from the Cambrian Stage 3 Chengjiang Konservat-Lagerstätte show that the Wiwaxia scleritome comprised nine equivalent transverse rows associated with outgrowths of soft tissue, but did not possess a separate zone of anterior sclerites. This serial construction is fundamentally incompatible with the circumferential disposition of sclerites in early molluscs, but does closely resemble the armature of certain annelids. A deep homology with the annelid scleritome must be reconciled with Wiwaxia's mollusc-like mouthparts and foot; together these point to a deep phylogenetic position, close to the common ancestor of annelids and molluscs.

Description

This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/srep14810

Keywords

Animals, Annelida, Fossils, Mollusca, Paleontology

Journal Title

Sci Rep

Conference Name

Journal ISSN

2045-2322
2045-2322

Volume Title

5

Publisher

Springer Science and Business Media LLC
Sponsorship
We acknowledge funding from the National Natural Science Foundation of China (NSFC 41425008, to ZZF), the Fok Ying Tung Education Foundation (G121016, to ZZF), the Ministry of Education of China (NCET-11-1046, to ZZF), the Geological Society of America (MRS) and Clare College, Cambridge (MRS). Fossil collection was partly financed by the National 973 Program (2013CB835002) and 111 Projects of China (P201102007).