Arumberia

Arumberia
Temporal range: Late Ediacaran
Scientific classification
Kingdom: incertae sedis
Genus: Arumberia
Glaessner et Walter, 1975
Type species
Arumberia banksi
Glaessner et Walter, 1975
Species
    • A. banksi
    • A. vindhyanensis
    • A. usvaensis
    • A. multykensis
    • A. beckeri
    • A. ollii

    Arumberia is an enigmatic fossil from the Ediacaran period[1] originally described from the Arumbera Sandstone, Northern Territory, Australia[2] but also found in the Urals,[3] East Siberia,[4] England and Wales,[5] Northern France,[5] the Avalon Peninsula[5] and India.[6] Several morphologically different species are recognized.[3]

    Description

    Arumberia appears as a poorly-delimited series of fine parallel grooves arising from a single region or point. A typical description of Arumberia banksi is given in Pandey and Kumar (2009):[6]

    It consists of array of straight to gently curved parallel to subparallel ridges about 1 – 3 mm wide and separated by flat to gently concave furrows of 1 – 7 mm in width. Relief from ridge top to furrow bottom is less than 1mm. Ridge ranges in length from 1.5 cm to 14.5 cm. Generally the ridges are parallel, but they also bifurcate. Ridges are developed on plane and rippled surfaces.

    — Pandey S.K., Kumar S. (December 2009). "NOTE ON THE OCCURRENCE OF ARUMBERIA BANKSI AND ASSOCIATED FOSSILS FROM THE JODHPUR SANDSTONE, MARWAR SUPERGROUP, WESTERN RAJASTHAN". Journal of the Paleontological Society of India 54 (2): 171–178.

    Identity

    The identity of Arumberia is controversial. Arumberia has been originally interpreted as a 5–20 cm high cup-like organism, apparently composed of flexible tissue, attached to the sea bottom by a blunt apex[2] or, later, as a colonial organism made of flexible, thin-walled tubes tightly joined together through their length.[5] Affinities with Ernietta, Conostichus, Pteridinium, Palaeoplatoda, Phyllozoon and Bergaueria and Chuaria have been conjectured.[5] Spheroidal objects found along with Arumberia have also been interpreted as "dispersable stage" of Arumberia itself.[5]

    Conversely, a non biological interpretation has been put forward[1][7] Experiments in fact reproduced Arumberia-like traces from flume experiments[8] and from the flux of water around small objects.[9] The absence of Arumberia-like structures after the Ediacaran period could be due to the unique properties of the microbial mat that covered the sea floor at the period.[1] However there is still debate, with recent analysis of Urals' Arumberia-like structures leaning towards a biological interpretation as an organism adapted to shallow water environments.[3]

    See Also

    List of Ediacaran genera

    References

    1. ↑ 1.0 1.1 1.2 McIlroy, D.; Walter, M. (1997). "A reconsideration of the biogenicity of Arumberia banksi Glaessner & Walter". Alcheringa: an Australasian Journal of Palaeontology 21: 79. doi:10.1080/03115519708619187.
    2. ↑ 2.0 2.1 Glaessner, M. F.; Walter, M. R. (1975). "New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia". Alcheringa: an Australasian Journal of Palaeontology 1: 59. doi:10.1080/03115517508619480.
    3. ↑ 3.0 3.1 3.2 Maslov, A.V., Kolesnikov, A.V.; Grazhdankin, D.V. (2012). "Arumberia-type structures in the Upper Vendian of the Urals". Doklady earth sciences 447 (1): 1233–1239. Retrieved 27 January 2013.
    4. ↑ Gómez-Pérez M., Bogolepova O.K.; Gubanov A.P.; Howard J.P. (2010). "Arumberia and other microbial mats from the Neoproterozoic-Cambrian strata of East Siberia.". Geophysical Research Abstracts. Retrieved 27 January 2013.
    5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Bland, B. H. (1984). "Arumberia Glaessner & Walter, a review of its potential for correlation in the region of the Precambrian–Cambrian boundary". Geological Magazine 121 (6): 625–633. doi:10.1017/S0016756800030776.
    6. ↑ 6.0 6.1 Pandey S.K., Kumar S. (December 2009). "NOTE ON THE OCCURRENCE OF ARUMBERIA BANKSI AND ASSOCIATED FOSSILS FROM THE JODHPUR SANDSTONE, MARWAR SUPERGROUP, WESTERN RAJASTHAN". Journal of the Paleontological Society of India 54 (2): 172. Retrieved 27 January 2013.
    7. ↑ Brasier, M. D. (1979). ""The Cambrian radiation event."". The origin of major invertebrate groups. London, New York: Academic Press. pp. 103–159.
    8. ↑ Walton, E.K., Dzulynski, S. (1965). Sedimentary Features of Flysch and Greywackes. Amsterdam: Elsevier. p. 282.
    9. ↑ Allen, J.R.L. (1982). Sedimentary structures, their character and physical basis. Part II. Amsterdam: Elsevier. pp. 1–676.