Complex behavioural patterns and ethological analysis of the trace fossil Zoophycos: evidence from the Lower Devonian of South China

The trace fossil Zoophycos is abundant in the shallow‐marine deposits (tempestites) of the Lower Devonian (Emsian) Yangmaba Formation in Ganxi of Sichuan, South China. It often occurs as part of complex trace fossils that comprise different integrated elements: scratch traces, simple to complex spreiten structures with marginal tubes (Zoophycos) and vertical tunnels. The complex Zoophycos burrows consist of spreiten with a marginal tube, preserved as convex hyporeliefs on the sole of an erosion surface. The exquisite, complex spreiten are interpreted to have been formed by deposit‐feeding behaviour, where the animal constructed the trace upwards without leaving faeces in the spreiten. The width of the marginal tube in different whorls is almost constant. The scratches are observed on the wall of the marginal tubes. The Zoophycos intergrades with Spongeliomorpha and Chondrites and was later cut by vertical shafts. All these features together indicate that the Zoophycos‐maker might have been a vermiform polychaete instead of a predator such as a decapod crustacean (Spongeliomorpha producer). Based on stratigraphical and ichnological features, the complex trace fossils resulted from the complex activity of different opportunistic organisms (r‐strategist) that quickly occupied and thrived within the quiet, nutrient‐rich environment after storm events.     

贵州独山中泥盆世动藻迹生态习性探讨

贵州独山中泥盆统产有丰富的遗迹化石Zoopkycos,现从其产出的特征和古生态等方面对其生活习性进行探讨。认为分布于静水、贫氧、有机质丰富环境的Zoopkycos为螺旋向上的内生觅食构造;边缘管一端通过中央通道与海水相通,呈“J”形;蹼状构造系造迹生物觅食区域的扩大、边缘管增大而形成;同一个体的Zoopkycos可以分出许多的与蹼状构造变化规律相近的、具同一边缘管的觅食序列(food-system),每一觅食序列的边缘管具有一端向上与中央通道相通,另一端向下与相邻觅食序列的边缘管相联;螺旋的疏密、大小与相对沉积速度有关。产于独山地区中泥盆统的Zoopkycos的造迹生物可能是星虫类(sipunculids)。     

Balanoglossites Mägdefrau, 1932 from the middle triassic of Germany: part of a complex trace fossil probably produced by burrowing and boring polychaetes

The ichnogenusBalanoglossites Mägdefrau, 1932 is re-described from its type area and is interpreted as part of a complex trace fossil comprising both burrow and boring components. The type ichnospecies,B. triadicus, consists of predominantly deep U- or Y-shaped tunnel elements, whereasB. ramosus n. isp. encompasses irregularly ramified galleries. Both ichnospecies occur frequently in firmground and hardground substrates with sporadic epikarst features. In the underlying softground, they may integrate intoLabyrintichnus terrerensis Uchman &; Álvaro, 2000, a network of irregular galleries and communicating shafts. On the omission surface, the tunnels are linked to elongated or winding grooves in hard or firm substrates. Further elements of the complex trace fossil include lobate burrows similar toZoophycos andRhizocorallium, mainly occurring in firmground and softground, shallow to deep U-shaped pouches and winding tunnels (Maeandropolydora sulcans Voigt, 1965) in hard and firm substrates. Finally, some tunnel portions and well preserved top surfaces of the ichnofabrics are scattered with the faecal pelletsCoprulus oblongus Mayer, 1952.C. oblongus has a rounded shape and a homogeneous structure and belongs to the Coprulidae n. ichnofam. Based on the numerous fingerprints preserved in the complex trace fossil, polychaete worms are identified as possible tracemakers. This is in accordance with the close combination of borings and burrows, a tunnel system highly variable in shape and size, blind ending side-branches and tunnel terminations, association with scolecodonts and exceptionally preserved polychaete remains. In addition, different commensals may have contributed to the modification of the complex trace fossil.     

Behavioural interpretation of a rosetted spreite trace fossil: Dactyloidites ottoi (Geinitz)

Excellently preserved specimens of the trace fossil Haenrzschelinia onoi (Geinitz) allow its three-dimensional reconstruction and interpretation of the behaviour underlying the morphological pattern. H. onoi is a rosette-shaped endogenic trace fossil comprising central tube and branching incomplete radial protrusive spreiten. The basic behaviour pattern (rosetted vertical spreiten with central shaft) is the same as that of Brooksella Walcott 1896 and Dactyloidites Hall 1886. Haentzschelinia is therefore placed in synonymy with Dactyloidites , which has priority.     

Lower Cretaceous (Albian) shell-armoured and associated echinoid trace fossils from the Sácaras Formation, Serra Gelada area, southeast Spain

The Sácaras Formation (Albian, Lower Cretaceous) of the Serra Gelada succession (Prebetic of Alicante), southeast Spain, comprises carbonate‐rich, upwards thickening parasequences in which many types of trace fossils have been identified. The present study focuses on two types of tubular trace fossil characterized by features of their external coating. The first type is represented by a shell‐covered, structured trace fossil, up to 4?cm in diameter and 40?cm in length, built horizontally, from rectilinear (type 1) to gently curved (type 2), which envelopes an unstructured pipe of grey silty sediment. The coating is characterized by imbricated, flat particles, mainly orbitolinid foraminifers and other planar bioclasts, forming thin concentric layers; in cross section the bioclasts produce a typical plumed structure. This trace fossil represents a new ichnogenus and ichnospecies, here named Ereipichnus geladensis. Particle arrangement of the external coating is similar to that of terebelloid tubes, but Ereipichnus is a horizontal trace fossil, whereas structured worm tubes are vertical. The second type is a grain‐coated trace fossil, tubular in shape, with a simple internal structure. The coating is often reddish with respect to the neighbouring dark grey sediment and shows a slightly coarser‐grained texture, which envelopes the internal muddy pipe. This type, which yielded echinoids, was produced by irregular or heart‐shaped sea‐urchins (spatangoids) and is attributed to Scolicia or Cardioichnus. Facies analysis of the Serra Gelada succession with Ereipichnus and Scolicia or Cardioichnus locally shows other types of branched trace fossils (primarily represented by different forms of Thalassinoides) and bioturbation is developed in tiers, increasing upwards in abundance and diversity.     

Paleoecology of the Zoophycos producers

Kotake, Nobuhiro 1989 07 15: Paleoecology of the Zoophycos producers. Lethaia , Vol. 22. pp. 327–341. Oslo. ISSN 0024–1164.
Well-preserved Zoophycos and Spirophyton- like burrows occur in the Upper Pliocene deep-sea sediments exposed along the southern coast of Boso Peninsula, central Japan. They consist of an axial tunnel and helically coiled spreite with fecal pellets. In most cases the two kinds of trace fossil are found separately. In several complete specimens, however, the upper and lower portions represent a Spirophyton- like burrow and Zoophycos , respectively. The downward increase in size of the spreite and fecal pellets in a single burrow suggests that the complete Zoophycos was built successively as the producing animal grew. The occurrence of incomplete Zoophycos may have resulted from post-mortem destruction by echinoid locomotion and turbidity currents. In some cases, the uppermost portion of the axial tunnel is covered with a thin tuff layer. Fecal pellets in such burrows consist of the same tuffaceous material which must have originated from the overlying tuff layer. This fact indicates that the burrow producer did not feed on organic matter within the sediments but foraged detritus on the sea floor. The animal could probably stretch a part of the body from the top of the axial tunnel for feeding and systematically pack the fecal pellets into the sediments. Such segregation between the feeding place and the excretory space is interpreted as an efficient feeding strategy for the detritus-feeding burrowers in the deep sea. D Zoophycos, Spirophyton-like burrow, paleoecology, feeding and excretory behavior, Boso Peninsula, Japan .     

Ethological analysis of the trace fossil Zoophycos: hints from the Arctic Ocean

Löwemark, L. 2011: Ethological analysis of the trace fossil Zoophycos: Hints from the Arctic Ocean. Lethaia, Vol. 45, pp. 290–298. The distribution of the trace fossil Zoophycos in Quaternary marine sediments from the Arctic Ocean was studied in twelve piston and gravity cores retrieved during the Swedish icebreaker expeditions YMER80, Arctic Ocean‐96 and LOMROG I & II. The sampled cores span an area from the Makarov Basin to the Fram Strait. Zoophycos was only found in two cores taken at more than 2 km water depth on the slope of the Lomonosov Ridge, but was absent in cores obtained at shallower depth, confirming earlier observations of the trace maker’s bathymetric preferences. The two cores containing Zoophycos are characterized by quiet sedimentation and slightly enhanced food flux compared with the general Arctic. The occurrence of Zoophycos in these cores in a setting that is characterized by extreme seasonal variations in food flux due to the total ice coverage during winters and high primary productivity during the long summer days, is interpreted to be a cache‐behaviour response to pulsed flux of food to the benthic realm. □Arctic Ocean, ethology, Quaternary, spreiten, trace fossils, Zoophycos.     

再论假裸枝叠层石科*

内蒙古桌子山地区中奥陶统公乌素组遗迹化石十分丰富.本文共鉴定、描述14个遗迹属、17个遗迹种,其中1新遗迹属——Biscopulatichnus、4新遗种和6未定种.并根据不同遗迹属在不同层位中的相对丰度,建立了4个遗迹组合,自下而上的顺序是:1. Taenidium-Phycodes 组合;2. Volkichnium 组合;3. Helminthopsis 组合;4. Granularia-Circulichnus 组合,大致相当于 Seilacher (1967) 的 Zoophycos 遗迹相,反映出公乌素组沉积期,水体较深且宁静、缺氧、有机质含量高,推测应为大陆斜坡环境.     

Deep-sea echiurans: possible producers of Zoophycos

Kotake, N. 1992 07 15: Deep-sea echiurans: possible producers of Zoophycos.
The trace fossil Zoophycos in the upper Pliocene deep-sea deposits (Shiramazu Formation) distributed in the southernmost part of Boso Peninsula, central Japan, appears to be a product of feeding and excretory behavior by surface deposit-feeders inhabiting middle bathyal depths. Ecology and anatomy of modern deep-sea echiurans are consistent with those of the Zoophycos producers based on the Pliocene examples. Consequently, deep-sea echiurans may be producers of Zoophycos . Systematic lamellae structures of the spreite reflect excretory behavior in sediment resulting from deposit-feeding on the sea-floor. Z oophycos , deep-sea echiurans, Pliocene, Boso Peninsula, Japan .     

Zoophycos size may indicate environmental gradients

Detailed examination through a continuous stratigraphic interval representing nearly the entire Lower Devonian Onesquethawan Stage shows that the presence and size of the trace fossil Zoophycos varies systematically throughout the unit. The lithofacies of this sequence are interpreted to represent a double offshore-nshore cycle. Both maximum and mean diameters of the Zoophycos web (=spreite) are relatively large within a more offshore setting and become progressively smaller towards both margins of this geographic (= stratigraphic) zone. Close inspection of Zoophycos morphology reveals a nearly perfect correlation (r = 0.96) between Zoophycos web diameter and meniscus height. Meniscus height bears a constant relationship to the maximum body diameter of the animal creating the burrow, consequently, size of the web is directly proportional to body size. Thus the animal is largest near the center of its environmental range and smallest near the margins. Other ichnofossils in the section ( Scalarituba, Phycodes, Chondrites ), measured on a more limited scale, show similar size variations with smaller forms at the margins of their respective ranges. Therefore, trace fossil size may be a sensitive indicator of paleoenvironmental gradients.     

A modern analogue for the trace fossil Gyrolithes: burrows of the thalassinidean shrimp Axianassa australis

The tidal flats at Praia do Araça, Brazil have muddy siliciclastic sediments on the surface and a layer of heavily packed shells down to 30–40 cm depth. The most obvious element of the infauna is the thalassinidean shrimp Axianassa australis. Several animals were captured with a yabby pump. Burrow openings were characterized by a low mound (1-2 cm high and 10–30 cm in diameter at the base) with one or two simple holes nearby (20-70 cm away). Counts along two transects showed a mean density of Axianassa burrow openings of 1.4 m⁻² (range: 0–7), mounds ranged in density from 0 to 3 m⁻² (mean 1.25). Three nearly complete (and several incomplete) resin casts showed a unique burrow shape, with spiral shafts leading to wide horizontal galleries from which several evenly proportioned corkscrew-shaped spirals branched off, leading to further horizontal galleries at greater sediment depths. Burrows had up to 15 such spirals and a total length of over 8 m. The total burrow depth was between 106 and 130 cm. The role of the spirals and the similarity of Axianassa burrows to the trace fossil Gyrolithes are discussed.     

The oldest Mesozoic nearshore Zoophycos: evidence from the German Triassic

The trace fossil Zoophycos has been described from the Middle Triassic carbonates of the German Basin for the first time. It occurs in a calcilutite bed at the top of a shallowing-upward cycle (parasequence) in the transgressive systems tract of the Middle to Upper Muschelkalk sequence of Thuringia (Germany). Based on sedimentological and palaeontological features, the studied interval is interpreted as deposited in a marine nearshore environment with proximal storm deposits (tempestites). Zoophycos occurs in a very simple planar form with lobate spreiten, which were most likely produced by a worm-like animal by strip mining. The upper tier of the ichnofabric consists of Zoophycos, whereas the lower tier is occupied by cylindrical trace fossils of unknown taxonomic affiliation and with decreasing size towards the bottom. Associated trace fossils such as Rhizocorallium, Balanoglossites and Trypanites indicate a partly firm to hard substrate. No mixed layer is developed at the top of the trace fossil bearing succession. The ichnofabric together with the sedimentological features (disseminated pyrite, blue-grey colour) and palaeontological circumstances (poor benthic fauna, meiofauna with a small body size) support an interpretation of a dysaerobic environment. In the view of evolutionary change, Palaeozoic Zoophycos occurs in both deep and shallow marine deposits, whereas Mesozoic and Cenozoic Zoophycos is only common in shelfal and deeper-marine deposits. The new finding from the shallow-marine Middle Triassic represents the first reliable occurrence of Zoophycos after the end-Permian mass extinction and shows close similarities to its Palaeozoic precursors. It demonstrates that the producer survived the end-Permian mass extinction, became re-established in the nearshore realm and progressively colonized deeper-marine environments during the Mesozoic and Cenozoic.     

A new possible bivalve burrow Oblongichnus solodukhoi from the late Kazanian (middle Permian) stratotype section in Russia

A burrow previously assigned to the ichnotaxon Palaeophycus insignis is redescribed, and a new ichnotaxon Olongichnus solodukhoi n. igen. n. isp is erected for this flattened, slightly curved, multi-oriented, smooth burrow that has a thick lining with internal and external very fine-grained mucuous layers. It shows subrectangular to oblong form in cross section. O. solodukhoi is collected from the lowermost part of the Member D (Seryi Kamen Member, Pechishchi Beds) of the late Kazanian (middle Permian) stratotype section (East European Platform). It occurs in yellowish grey dolostone formed within open shallow-marine environments. O. solodukhoi records combined feeding and dwelling behaviours of a suspension-feeding organism. It could be produced by burrowing organisms with a simple flattened morphology, such as flatworms or polychaetes; however, we favour elongate and ultra-elongate bivalves as the potential tracemakers of the reported burrows.     

Possible traces of feeding by beetles in coniferophyte wood from the Kazanian of the Kama River basin

Possible traces of feeding by wood-boring beetle larvae (Coleoptera, ?Permocupedidae) are described from the Middle Permian locality Tikhie Gory (Tatarstan, right bank of the Kama River, Kazanian Stage). The traces in the form of perpendicular tunnels and shafts were left in picnoxylic wood of some coniferophytes s.l. (the orders Pinales, Cordaitales, or Vojnovskyales).     

The Complex Fungal Microboring Trace Saccomorpha stereodiktyon isp. nov. Reveals Growth Strategy of its Maker

A complex microboring trace of fungal affinity is described in shells as a new ichnotaxon Saccomorpha stereodiktyon isp. nov. and compared with the earlier established ichnotaxon Saccomorpha terminalis Radtke, 1991. The new trace is characterized by a three-dimensional network of tunnels composed of a bifurcate horizontal (parallel to substrate surface) network with an upright (perpendicular to surface) system of tunnels and by the formation of cylindrical to multilobate terminal sporangial swellings. The new trace shares with Saccomorpha terminalis Radtke, 1991 the terminal position of sporangial swellings but differs from this ichnotaxon by its complexity in spatial arrangement, segmented construction, and ramification of tunnels. The horizontal parts of the network in the new taxon adhere to the substrate surface and regularly produce thinner tunnels that explore the interior of the substrate, allowing the producer to participate in digestion of organic lamellae incorporated in the shell. Microborings similar to the new trace fossil have been observed in modern bivalve shells of the Atlantic Ocean, North Sea, Adriatic Sea and Red Sea at depths ranging from the intertidal down to 1,550 m. The fossil record of the trace reaches back to the Jurassic and the type material stems from a Lower Oligocene oyster shell. The study shows that complex microboring traces reflect both behaviour and developmental strategy of their makers.     

Lunulichnus Tuberosus Ichnogen. and Ichnosp. Nov. from the Early Eocene Wasatch Formation,Fossil Butte National Monument,Wyoming: An Arthropod-Constructed Trace Fossil Associated with Alluvial Firmgrounds

A new trace fossil, Lunulichnus tuberosus, is described from fluvial deposits of the Wasatch Formation (early Eocene) at Fossil Butte National Monument, southwestern Wyoming, USA. L. tuberosus are straight, vertical to obliquely oriented, unlined cylindrical burrows with pronounced crescent-shaped wall sculptings. In situ examples of these trace fossils are most commonly preserved as sand-filled casts emanating from the erosional bases of fluvial channel sandstone bodies into underlying floodplain mudstone/siltstone beds. L. tuberosus is interpreted as the dwelling trace of a stream-dwelling decapod crustacean. Excellent preservation of fine detail, particularly their diagnostic crescent-shaped wall sculptings, support the hypothesis that L. tuberosus were excavated in firm substrata subjacent to fluvial erosional surfaces. As such, they are interpreted as constituents of alluvial Glossifungites trace fossil assemblages.     

A new ichnospecies of Fuersichnus from the Cretaceous of Antarctica and its paleoecologic and stratigraphic implications

A new ichnotaxon is recognized in the Hidden Lake Formation, Upper Cretaceous of James Ross Island, Antarctica. Fuersichnus striatus consists of horizontal to subhorizontal, isolated or loosely clustered, U‐shaped, curved to banana‐like burrows, characterized by distinctive striations parallel to the trace axis. It is interpreted as a dwelling structure probably produced by crustaceans or polychaetes. This recording of Fuersichnus extends its stratigraphic range from the Triassic‐Jurassic to the Cretaceous and its environmental setting from nonmarine to marine environments. F. striatus typified consolidated, but unlithified substrates. Accordingly, it must be considered a member of the Glossifungites ichnofacies.     

Reappraisal of Schaubcylindrichnus: A probable dwelling/feeding structure of a solitary funnel feeder

The ichnogenus Schaubcylindrichnus has been considered as a cluster of multiple J-shaped tubes, all of which show congruency. Based on such a reconstruction, the trace fossil has commonly been regarded as dwelling tubes of gregarious, head-down deposit-feeding animals.

Well-preserved specimens of Schaubcylindrichnus are found in Miocene and Pleistocene strata of Japan. The trace fossil consists of a bundle of closely spaced, thickly lined tubes, each of which shows a gentle bow-like bend curving downward in a vertical to oblique plane. As individual tubes in a single bundle frequently show size-gradation of diameter, branching and/or cross-cutting, it is probable that the bundle was formed through successive burrowing by a solitary producer. In a longitudinal section of well-preserved specimens, a funnel-like, sediment-filled structure, which is attached to an upper end of a limb of the bow-shaped bundle, is observed. At the other end of the limb, there is a mound-like structure of sediment that is piled up from the bedding surface. The trace fossil was probably a burrow system of a solitary funnel-feeding animal, like an enteropneust.

According to comparisons with type specimens of the ichnospecies of Schaubcylindrichnus, namely, topotypes of Schaubcylindrichnus coronus and holotype and paratypes of S. freyi, S. freyi can be regarded as a junior synonym of S. coronus. As the topotype specimens of S. coronus have many common features with the traces in Japan, the latter should be included in the former. S. coronus therefore is concluded as the burrow system of a solitary funnel feeder.     

Intertidal burrows of the air-breathing eel goby, <Emphasis Type="Italic">Odontamblyopus lacepedii</Emphasis> (Gobiidae: Amblyopinae)

Odontamblyopus lacepedii inhabits burrows in mudflats and breathes air at the surface opening. Investigations of the intertidal burrows using resin casting demonstrated a highly branched burrow system. The burrows are composed primarily of branching patterns of interconnected tunnels and shafts that communicate into two to seven surface openings. Bulbous chambers (i.e., dilated portions of the burrow) at branching sections of the tunnels or shafts are common features of the burrow. The presence of these chambers accords the fish adequate space to maneuver inside the burrow, and thus constant access to the surface. The combination of all burrow characteristics and previously reported variability in air breathing patterns are ostensibly of selective value for aerial predator avoidance during air breathing in O. lacepedii.     

陕西宁强埃迪卡拉系顶部管状化石Sinotubulites形态学与古生态学新知

陕西宁强选将坪地区埃迪卡拉系灯影组高家山段上部的碎屑白云岩中产出大量磷酸盐化三维立体保存的Sinotubulites化石,这为埃迪卡拉纪末期生物的演化及多样性研究提供了一个很好的窗口。文中通过对Si-notubulites的形态结构、纹饰特征、保存特征等方面的观察研究,认为Sinotubulites管体外壁上不规则的褶皱状纹饰是变形过程中展现出的各种形态,而不是管体固有的纹饰形态特征。并且根据管体内外层管壁的不同形态学特征以及在原始生态条件下弯曲生长的管体,将Sinotubulites解释为表栖平躺生物。Sinotubulites可能具有一定的蠕动能力,而不规则褶皱状外壁在变形过程中可以产生微弱的蠕动力,使得管体对自身的位置得以调整。