DOI: 10.1016/j.palaeo.2016.11.053
论文题名: Palaeoecology and taphonomy of spatangoid-dominated echinoid assemblages: A case study from the Early-Middle Miocene of Sardinia, Italy
作者: Mancosu A. ; Nebelsick J.H.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 466 起始页码: 334
结束页码: 352
语种: 英语
英文关键词: Bioturbation
; Infaunal tiering
; Preservation potential
; Spatangoids
; Sublittoral environments
英文摘要: The Early-Middle Miocene marine sedimentary succession of the Borutta Formation cropping out at Porto Torres (northern Sardinia) represents one of the most diverse and well-preserved spatangoid-dominated sedimentary successions in the Miocene of the Mediterranean area. The echinoid-bearing succession is studied with the twofold purpose of firstly reconstructing the palaeoenvironmental setting in which these echinoids occurred, and secondly investigating factors influencing the preservation potential of spatangoid echinoids in the fossil record. These goals are accomplished by 1) detailed logging of sedimentary facies, 2) applying functional morphological interpretations of echinoid skeletons in order to reconstruct their behaviour and life habits, 3) quantifying the relative abundance of taxa and taphonomic features of test preservation, and 4) analyzing associated trace fossils within the beds. The sedimentary succession is composed mainly of fine-grained sandstones which are intensely bioturbated by Thalassinoides-like burrows. Spatangoid abundance is high throughout the profile declining only in intercalated dm-thick rhodolith beds. A 20-cm-thick bed with a bedding surface of approximately 250 m2 was investigated in detail with respect to relative abundance of spatangoid taxa and taphonomic signatures. The echinoids consist almost exclusively of deposit-feeding irregular forms with a dominance of the spatangoids Ova and Brissopsis and the minute clypeasteroid Echinocyamus. The spatangoids Opissaster, Holanthus, Metalia and Hemipatagus as well as the clypeasteroid Clypeaster marginatus are also present. A low energy, moderately deep, outer sublittoral environment with high rates of bioturbation and episodes of sediment deposition by storms is inferred. Interspecific competition among deposit-feeding echinoids appears to be limited by their different burrowing depths, feeding strategies and resource partitioning. The gregarious behaviour of spatangoid echinoids, their habitat in quiet, deeper environments and episodes of rapid deposition seem to represent the main factors leading to this spatangoid-bearing deposit. Since both shallow- and deep-burrowing spatangoid echinoids are well represented as complete specimens, mode of life does not appear to play a major role in their preservation potentials. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68021
Appears in Collections: 过去全球变化的重建
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作者单位: Dipartimento di Scienze Chimiche e Geologiche, Università degli studi di Cagliari, Via Trentino 51, Cagliari, Italy; Institut für Geowissenschaften, Universität Tübingen, Sigwartstraße 10, Tübingen, Germany
Recommended Citation:
Mancosu A.,Nebelsick J.H.. Palaeoecology and taphonomy of spatangoid-dominated echinoid assemblages: A case study from the Early-Middle Miocene of Sardinia, Italy[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,466