Abstract Zoophycos in the Mississippian Mobarak Formation (Central Alborz, Iran) shows its potential in interpreting depositional settings, ecological features and sequence stratigraphy. Zoophycos A (ZoA), Zoophycos B (ZoB), Zoophycos/Phycosiphon (Zo/Phy) and Phycosiphon (Phy) ichnocoenoses are identified in the middle and outer ramp facies of the Mobarak Formation on the basis of shape, ichnodensity, ichnocomplexity degree and size of Zoophycos and other trace fossils. Zoophycos portrays a proximal-to-distal trend in the storm-dominated ramp sequence. In deeper parts of the ramp with long-term stable conditions and organic enrichment, Zoophycos producers selected equilibrium strategies (K-selected), whereas into the shallower parts they opted for opportunistic behavior (r-selected) due to short-term stable conditions with low food flux. The feeding behavior proposed in this study is based on general morphology as well as mode of sediment exploiting, and includes deposit feeding and the caching model. Moreover, this study confirms that the distribution pattern of the Paleozoic Zoophycos producers within a sequence stratigraphic framework that was totally different from that of the Mesozoic and Cenozoic. During the late transgressive systems tract (TST) and early highstand systems tract (HST), the excess of benthic food and the environmental stability, together with the prevalence of dysaerobic conditions, caused intense burrowing by the Zoophycos producer in proximal outer ramp to distal middle ramp. Its ethology, paleoecologic strategies and taphonomic signatures suggest that erosionally-exhumed, dewatered muddy beds (firmground) were not able to provide appropriate conditions for deposit-feeding Zoophycos producers as a consequence of their lower environmental stability. Therefore, Zoophycos as a standard component of the resident fair-weather community cannot be a good representative of the distal expression of the Glossifungites ichnofacies.

中文翻译：

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伊朗北部密西西比 Mobarak 组中古环境和层序地层的微量化石 Zoophycos 的变化

摘要 密西西比州 Mobarak 组（伊朗中部阿尔伯兹）中的 Zoophycos 显示出其在解释沉积环境、生态特征和层序地层方面的潜力。在Mobarak组的中外斜坡相中，根据形状、地层密度、地层复杂度和地层复杂度，确定了藻藻A（ZoA）、藻藻B（ZoB）、藻藻/藻藻（Zo/Phy）和藻藻藻（Phy）。 Zoophycos 和其他痕迹化石的大小。Zoophycos 描绘了风暴主导的斜坡序列中从近端到远端的趋势。在具有长期稳定条件和有机富集的斜坡的较深部分，Zoophycos 生产商选择了平衡策略（K 选择），而在较浅的部分，由于短期稳定条件，他们选择了机会主义行为（r 选择）低食物通量。本研究提出的取食行为基于一般形态和沉积物开采模式，包括沉积物取食和缓存模型。此外，本研究进一步证实了古生代动物藻生产者在一个与中、新生代完全不同的层序地层框架内的分布格局。在晚海进系统域 (TST) 和早期高位系统域 (HST) 期间，底栖食物的过剩和环境稳定性，以及厌氧条件的普遍存在，导致 Zoophycos 生产者在近端外斜坡到远端中部的剧烈挖洞坡道。它的行为学、古生态学策略和埋藏学特征表明，侵蚀出土的、由于环境稳定性较低，脱水泥浆床（硬地）无法为以沉积物为食的 Zoophycos 生产者提供适当的条件。因此，作为常住晴天群落的标准组成部分的 Zoophycos 不能很好地代表 Glossifungites ichnfacies 的远端表达。