Topic
Myoscolex
About: Myoscolex is a research topic. Over the lifetime, 5 publications have been published within this topic receiving 202 citations.
Papers
TL;DR: Glaessner et al. as mentioned in this paper reported the oldest phosphatized muscle tissue from the Lower Cambrian Emu Bay Shale of South Australia, which is the most abundant soft-bodied taxon in the Big Gully fauna.
Abstract: Most of the specimens of Myoscolex ateles Glaessner, 1979, the most abundant soft-bodied taxon in the Big Gully fauna from the Lower Cambrian Emu Bay Shale of South Australia, preserve only the phosphatized trunk muscles, in striking contrast to the organic residues that characterize other Burgess-Shale-type biotas. This is the oldest phosphatized muscle tissue and the first thus far reported from the Cambrian. The extent of phosphatization implies a source in addition to the animal itself, and this is reflected in high levels of phosphate in the Big Gully sequence compared to other shales. The apparent anomaly posed by the extensive preservation of labile muscle tissue as opposed to the more decay resistant cuticle is explained by the role of bacterial processes in the preservation of soft tissues. New specimens of Myoscolex reveal a variable number of trunk somites with possible tergites, and flap-like appendages. There is evidence for at least three eyes on the head, and a proboscis may have been present. An annelid affinity is rejected and Myoscolex is reinterpreted as an Opabinia-like animal with possible affinities with the arachnomorph arthropods.
50 citations
TL;DR: The lower Cambrian sediments of the Flinders Ranges, South Australia can be divided into three sequence sets as mentioned in this paper : sequence set ϵ1 comprises lower clastic units overlain by a carbonate dominated marine succession that shows marked lateral and vertical facies changes.
Abstract: The lower Cambrian sediments of the Flinders Ranges, South Australia can be divided into three sequence sets. They rest unconformably on the Ediacaran succession. Sequence set ϵ1 comprises lower clastic units overlain by a carbonate dominated marine succession that shows marked lateral and vertical facies changes. Sequence sets ϵ2 and ϵ3 together comprise a largely clastic dominated succession of marginal marine to non-marine sediments with subordinate shallow marine carbonates. Sequence set ϵ1 is richly fossiliferous at some levels with biostratigraphy established for trilobites, archaeocyaths, brachiopods, small shelly fossils, acritarchs and molluscs. The Emu Bay Shale Lagerstatte (Cambrian Series 2) from the north coast of Kangaroo Island occurs within a clastic-rich shelf succession dominated by conglomerate and sandstone. The fossil content is dominated by trilobites in terms of relative abundance and currently over 50 taxa are known including, Anomalocaris, the bivalved arthropods Isoxys and Tuzoia, the nektaspids Emucaris and Kangacaris, the megacheiran Oestokerkus amongst a variety of other arthropods. Other common taxa include palaeoscolecid worms, Myoscolex, sponges, hyoliths, brachiopods, a vetulicolian and several other enigmatic forms. The oldest known well preserved complex arthropod eyes occur in this biota.
46 citations
TL;DR: Dzik, J. (2004).
Abstract: Dzik, J. (2004). Anatomy and relationships of the Early Cambrian worm Myoscolex. —Zoologica Scripta, 33, 57–69.
Numerous fossil specimens of Myoscolex ateles Glaessner, 1979 from the late Early Cambrian Emu Bay shale of Kangaroo Island, South Australia with phosphatized organic matter-rich tissues show its muscular body wall penetrated by rows of rod-like structures — possible chaetae. The body wall was composed of an external layer with transverse (circular) fibres. This layer was thickest in lateral parts of the body and very thin dorsally. In the ventro-lateral quarter of the body circumference, a belt of longitudinal fibres extended along the body. Longitudinal fibres also occurred in the dorsal region of the body. Along the venter extended a narrow longitudinal belt of probably oblique cords, crossing themselves perpendicularly. In having a virtually smooth, laterally flattened body, Myoscolex closely resembles the slightly geologically younger Pikaia from the Burgess shale of British Columbia, generally believed to be one of the oldest chordates. Being the oldest probable annelid, at least superficially similar to the opheliid polychaetes, Myoscolex may appear not too distant from the ancestor of the phylum. The lateral body flattening of Myoscolex was apparently an adaptation to swimming by undulation of the body in transverse plane, similar to today's errant polychaetes but without using chaetae or appendages in propulsion.
21 citations
TL;DR: The Lower Cambrian Emu Bay Shale contains in its lower part, exposed near White Point on the north coast of Kangaroo Island, an unusual assemblage of phyllocarid crustaceans and annelid worms that appears to be a thanatocoenosis deposited in a reducing environment but preservation of the worms is largely due to diagenetic calcification of their soft tissues.
Abstract: The Lower Cambrian Emu Bay Shale contains in its lower part, exposed near White Point on the north coast of Kangaroo Island, an unusual assemblage of phyllocarid crustaceans (Isoxys communis sp. nov., Tuzoia australis sp. nov.) and annelid worms (Palaeoscolex antiquus sp. nov., Myoscolex ateles gen. et sp. nov., Vetustovermis planus gen. et sp. nov.), together with Estaingia and redlichiid trilobites. This appears to be a thanatocoenosis deposited in a reducing environment but preservation of the worms is largely due to diagenetic calcification of their soft tissues.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2012 | 1 |
| 2004 | 1 |
| 1997 | 2 |
| 1979 | 1 |