Fractofusus
| Fractofusus | ||||||||
|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||
| Ediacarium | ||||||||
| 575 to 560 million years | ||||||||
| Locations | ||||||||
| Systematics | ||||||||
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| Scientific name | ||||||||
| Fractofusus | ||||||||
| Gehling and Narbonne , 2007 | ||||||||
Fractofusus is a fossil from the Ediacarium Newfoundland , which iscountedamong the Rangeomorpha and was previously described in the genus Fractofusus misrai .
Discovery and type locality
Fractofusus misrai was discovered in the summer of 1967 by the Indian geologist SB Misra during his master's thesis at Mistaken Point on the Avalon Peninsula in Newfoundland. The discovery of the Mistaken Point biota was published in the science journal Nature in 1968 . The first scientific description of the taxon was not until 2007 by Gehling and Narbonne, who named it after Professor Misra. The first descriptors described a second species of the genus, Fractofusus andersoni , in the same work .
etymology
The generic name Fractofusus ('broken spindle') is a compound word created from the Latin fractus ('broken, broken') and fusus ('spindle'). The species name misrai is the Latin genitive of the discoverer's name.
description
Fractofusus reached body sizes with a length between 3 and 22 centimeters and a width of 1 to 8 centimeters. The organism had a flat, spindle-shaped body made up of at least two flat leaf-shaped structures that met at a zigzag-shaped central commissure. The top and bottom were not morphologically differentiated from one another. Each sheet consisted of elongated modules that extended from this central axis to the outer edge. The overall shape was oval, the modules in the middle were larger than those at both ends, each leaf consisted of 15 to 25 modules. The modules consisted of sub-modules, the shape of which corresponded to a smaller version of the overall module ( fractal organization).
In his diploma thesis from 1968, Misra describes in detail the fauna community found at Mistaken Point, their chronological position, the prevailing ecological conditions and the causes of their sudden disappearance. Another detailed report of the biota was published in 1969 in the Bulletin of the Geological Society of America .
Misra divided the fauna community into five groups:
- Spindles
- leaves
- Round shapes
- Dendrites
- Radial emitters
Each of these groups was defined by its particular distribution, physical appearance, sub-categories and biological affinity.
Misra described the geological conditions of the fossil-bearing sediments and the ecological conditions in what was then the Conception Sea in two subsequent papers from 1971 and 1981.
Taphonomy
Fractofusus is preserved in the sediments of the Mistaken Point Formation as an imprint or hollow form in fine-grained siltstone, which goes back to volcanic ash deposits. A submarine ash stream suddenly covered here apparently the busy ocean floor with the "fern frond-like" organisms (fronds), said fractofusus misrai -Fronds initially remained preserved and were molded by their decay into negative relief from the ashes. The first descriptors conclude from the conservation conditions that, unlike most Frondomorpha, they did not stand upright on the ocean floor in life, but rather crept on the surface.
Ecological reserve
The site is now part of the Mistaken Point Ecological Reserve , a 5.7 square kilometer stretch of coast where the fossil-bearing rocks are protected.
Individual evidence
- ↑ Anderson, MM and Misra, SB: Fossils found in pre-Cambrian Conception Group of southeastern Newfoundland . In: Nature . tape 220 , 1968, pp. 680-681 , doi : 10.1038 / 220680a0 .
- ↑ a b c Gehling, James G., Narbonne, Guy N .: Spindle-shaped Ediacara fossils from the Mistaken Point assemblage, Avalon Zone, Newfoundland . In: Canadian Journal of Earth Sciences . tape 44 (3) , 2007, pp. 367-387 , doi : 10.1139 / e07-003 .
- ↑ Misra, SB: Late Precambrian (?) Fossils from southeastern Newfoundland . In: Geological Society of America Bulletin . tape 80 (11) , 1969, pp. 2133-2140 , doi : 10.1130 / 0016-7606 (1969) 80 [2133: LPFFSN] 2.0.CO; 2 .
- ^ Misra, SB: Stratigraphy and Depositional History of Late Precambrian Coelenterate-Bearing Rocks, Southeastern Newfoundland . In: Geological Society of America Bulletin . tape 82 (4) , 1971, pp. 979-988 , doi : 10.1130 / 0016-7606 (1971) 82 [979: SADHOL] 2.0.CO; 2 .
- ^ Misra, SB: Depositional Environment of the Late Precambrian Fossil-Bearing rocks of Southeastern Newfoundland, Canada . In: Journal of Geological Society of India . tape 22 (8) , 1981.