Mollisonia symmetrica
| Mollisonia symmetrica | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| lower to middle Cambrian | ||||||||||||
| 515 to 500 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Mollisonia symmetrica | ||||||||||||
| Walcott , 1912 | ||||||||||||
Mollisonia symmetrica is an extinct species from the genus Mollisonia with an uncertain position within the arthropods (Arthropoda).
features
Mollisonia symmetrica was elongated, almost rectangular in the dorsal and almost triangular in the transverse view. The dorsal exoskeleton , consisting of an almost rectangular head shield, seven thorax segments ( tergites ) and a rather elongated tail shield , had an axial crest. The thorax segments were all roughly the same in length and width. The tail shield had three pairs of transverse extensions on the surface.
Limbs have not been preserved.
Locations
Specimens of this species have been found in the Burgess Shale in Canada and in the Wheeler Formation in Utah .
Systematics
Mollisonia symmetrica is the type species of Mollisonia and one of three known species of the genus established by Charles Walcott in 1912 .
swell
literature
- Zhang X.-L., Zhao Y.-L., Yang R.-D., Shu D.-G .: The Burgess Shale arthropod Mollisonia (M. sinica new species): New occurrence from the middle cambrian Kaili fauna of southwest China . Journal of Paleontology 76 (6), 2002: 1106-1108. HTML
- DEG Briggs, BS Lieberman, JR Hendricks, SL Halgedahl, RD Jarrard: Middle Cambrian Arthropods from Utah . Journal of Paleontology 82 (2), 2008: 238-254. HTML
Individual evidence
- ^ CD Walcott: Middle Cambrian branchiopoda, malacostraca, trilobita, and merostomata. Cambrian Geology and Paleontology II . Smithsonian Miscellaneous Collections 57, 1912: 145-228.