New Artiopodan Arthropods from the Early Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia

Title
New Artiopodan Arthropods from the Early Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia
Publication Date
2012
Author(s)
Paterson, John R
( author )
OrcID: https://orcid.org/0000-0003-2947-3912
Email: jpater20@une.edu.au
UNE Id une-id:jpater20
Garcia-Bellido, DC
Edgecombe, GD
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Paleontological Society
Place of publication
United States of America
DOI
10.1666/11-077.1
UNE publication id
une:12275
Abstract
The Emu Bay Shale Konservat-Lagerstätte (Cambrian Series 2, Stage 4) on Kangaroo Island, South Australia, is the source of two new non-biomineralized artiopodan arthropods. 'Squamacula buckorum' n. sp. is the first record outside of China of a genus otherwise known only from its type species, 'S. clypeata', from the Chengjiang biota. The Australian species displays the long cephalic doublure and spiniform exopod setae that are apomorphic for this genus, provides new information on the alimentary tract and mid gut glands (the latter preserved as three-dimensional, permineralized structures), and indicates inter specific variability in trunk segment numbers. The distribution of 'Squamacula' strengthens the bio geographic connections between early Cambrian "Burgess Shale-type" biotas of Australia and South China. 'Australimicola spriggi' n. gen. nsp. represents a monotypic genus resolved in a cladistic analysis of Cambro-Ordovician artiopodans as most closely related to or within Conciliterga (a clade containing 'Helmetia', 'Kuamaia', 'Kwanyinaspis', 'Rhombicalvaria', 'Saperion', 'Skioldia', and 'Tegopelte'). Compared with other members of this clade from Chengjiang and the Burgess Shale, the new genus is diagnosed by an elongate trunk with 23 thoracic tergites having spatulate pleural tips and a small pygidium possessing a single, elongate pair of pleural spines, with specimens also showing a hypostome attached to an anterior (or prehypostomal) sclerite, antennae, short endopods, an annulated alimentary tract, and a series of three-dimensional, permineralized mid gut glands. An alternative relationship between 'Australimicola' and the Early Ordovician-Early Devonian Cheloniellida explains the shared anterior flexure of trunk pleurae but forces dubious homologies in other characters, such as dorsally-articulated furcae versus spines.
Link
Citation
Journal of Paleontology, 86(2), p. 340-357
ISSN
1937-2337
0022-3360
Start page
340
End page
357

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