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Miocene siderite specimens from Salmon Creek, Washington. A, B, C, E, and G are coprolite-like extrusions that show pointed ends and longitudinal striations; D is a botryoidal concretion; F is an extruded mass with botryoidal encrustations.

Miocene siderite specimens from Salmon Creek, Washington. A, B, C, E, and G are coprolite-like extrusions that show pointed ends and longitudinal striations; D is a botryoidal concretion; F is an extruded mass with botryoidal encrustations.

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Excrement-shaped masses of siderite and limonite have been reported from clay-rich sedimentary rocks that range in age from Late Permian to Holocene, These objects have been widely accepted as being coprolites, but the ferruginous composition, absence of internal inclusions, and scarcity of associated vertebrate remains suggest that they may instea...

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... masses are abundant in massive beds of silty tuffaceous clay that resulted from alteration of water-laid andesitic tephra. Bot- ryoidal concretions (Fig. 3D) far outnumber excrement-shaped masses. Composite forms are common; they consist of extruded siderite that later became encrusted with botryoidal concretionary layers (Fig. 3F). Irregular mas- ses of siderite weighing several kilograms or more were observed eroding from these clay beds (Fig. 4). Roberts (1958) reported numer- ous ...
Context 2
... masses are abundant in massive beds of silty tuffaceous clay that resulted from alteration of water-laid andesitic tephra. Bot- ryoidal concretions (Fig. 3D) far outnumber excrement-shaped masses. Composite forms are common; they consist of extruded siderite that later became encrusted with botryoidal concretionary layers (Fig. 3F). Irregular mas- ses of siderite weighing several kilograms or more were observed eroding from these clay beds (Fig. 4). Roberts (1958) reported numer- ous disc-shaped siderite concretions along Ce- dar Creek, a tributary of Salmon Creek (secs. 30 and 31, T. 11 N., R. 1 E., and sec. 36, T. 11 N., R. 1 W.). This site also contains ...

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Abstract⎯The paper presents the lithological, mineralogical, and geochemical characteristics of the composition, structure, and organic matter of siderite nodules and host mudstones in the Lower Carboniferous (Tournaisian–Visean) siderite-bearing sequence exposed along the Kozhym River on the western slope of the Subpolar Urals. The obtained result...

Citations

... The fecal-like specimens of the Readlyn deposit have been consistently interpreted as coprolites by all studies of the deposit (Broughton et al. , 1978Broughton 1981Broughton , 2017Broughton , 2021Binda 1989, 1991;Schmitz and Binda 1991). In contrast, there is an extensive literature on the controversial origin of ferruginous specimens with similar external morphologies recovered from the Salmon Creek deposit since their discovery in the 1930s (Dake 1939;Major 1952;Amstutz 1958;Danner 1968Danner , 1994Spencer and Tuttle 1980;Spencer 1993;Seilacher et al. 2001;Mustoe 2001;Yancey et al. 2013;Mustoe and Leopold 2014). Debate is focused on whether the Salmon Creek specimens are coprolites from an unknown animal or animals, or are pseudo-coprolites that resulted from inorganic diagenetic processes consistent with the production of biogenic gas. ...
... The novel application of the micro-CT scans confirms this inwardly directed layering process for specimens of both the Readlyn and Salmon Creek deposits. This model contrasts with earlier models (Mustoe 2001;Yancey et al. 2013;Mustoe and Leopold 2014) for the origin of ferruginous Salmon Creek deposit specimens due to inorganic siderite precipitation from upwelling methane. ...
Article
The kaolin-rich lacustrine sediments of the Maastrichtian Whitemud Formation in southern Saskatchewan, western Canada, accumulated 3-dimensional goethite casts of fruits associated with innumerable coprolites. The interiors of the fruits and fecal droppings display evidence consisting of microbial mat activities that resulted in ferrihydrite-goethite transformation. The deposit provides the opportunity to compare how the taphonomic processes vary between fruit and fecal matter and resulted in differing biomineral fabrics developed concurrently in a single deposit. Rapid microbial ferrihydrite precipitation and transformation to goethite resulted in thin encrustations of goethite at the fruit-sediment and coprolite-sediment interfaces , cementing kaolin and quartz grains into a rigid framework. The entombment retarded decay and preserved mm-thick 3-dimensional molds, often with impressions of external surface textures in fine detail. Concentric growth layers of goethite progressed inward as the organic residues were consumed by microbial mats. The ferruginous casts were not the consequence of outwardly directed growth of siderite within the encasing kaolin sediment followed by an alteration to goethite, but the reverse process by which inwardly directed microbial-initiated growth fronts precipitated ferrihydrite-goethite. The resulting ferruginous casts preserve arrays of voids formerly occupied by bacterial colonies that developed into hollow goethite spherulites of radial-fibrous crystallites with varying coalescence. The abrupt reduction of microbial mat activity replacing organic residues terminated the growth of the concentric layers, but resulted in other goethite fabrics within interior core areas of fruits and fecal droppings. The interior core fabrics of fecal droppings consist of randomly oriented abiotic goethite platelets. In contrast, fruit interior fabrics consist of mixtures of biotic hollow spherulites and coalesced abiotic goethite platelets, indicative that microbial mat activity persisted throughout the taphonomy.
... Multi-metre thick kaolin beds of the Whitemud Formation (Maastrichtian) in southern Saskatchewan (Broughton et al. 1978;Broughton 2017) and the Wilkes Formation (Miocene) in Washington State (Mustoe 2001;Yancey et al. 2013) host two of the largest known terrestrial accumulations of coprolites or alternatively pseudo-coprolites. The distribution of these innumerable coprolites associated with each formation is constrained to a single narrowly defined deposit, one in Maastrichtian strata in southern Saskatchewan at the Readlyn deposit ( Fig. 1A; Broughton et al. 1978) and another in Miocene strata at a site along Salmon Creek near Toledo, Washington State (Fig. 1B;Mustoe 2001;Seilacher et al. 2001;Mustoe et al. 2009;Yancey et al. 2013). ...
... Multi-metre thick kaolin beds of the Whitemud Formation (Maastrichtian) in southern Saskatchewan (Broughton et al. 1978;Broughton 2017) and the Wilkes Formation (Miocene) in Washington State (Mustoe 2001;Yancey et al. 2013) host two of the largest known terrestrial accumulations of coprolites or alternatively pseudo-coprolites. The distribution of these innumerable coprolites associated with each formation is constrained to a single narrowly defined deposit, one in Maastrichtian strata in southern Saskatchewan at the Readlyn deposit ( Fig. 1A; Broughton et al. 1978) and another in Miocene strata at a site along Salmon Creek near Toledo, Washington State (Fig. 1B;Mustoe 2001;Seilacher et al. 2001;Mustoe et al. 2009;Yancey et al. 2013). The Whitemud Formation consists of continental kaolin beds regionally distributed across southern Saskatchewan and Alberta, and for the Wilkes Formation (Miocene) across southwestern Washington State. ...
... Each deposit has readily collectable 3-D casts of coprolites numbering in the hundreds of thousands (Fig. 2). The morphogenesis of these ferruginous faecal (or faecal-like) specimens has been controversial for decades, resulting in polarized interpretations as to representing faecal by-products of animal activity, albeit of unknown taxonomic affinity (Broughton 2017), or entirely inorganic products resulting from concretionary siderite diagenesis and thereby pseudo-coprolites (Spencer 1993;Mustoe 2001;Yancey et al. 2013). ...
Article
Two spatiotemporally distant deposits in western North America on differing sides of the K-Pg boundary are recognized to have accumulated innumerable ferruginous faecal-like specimens consisting of 3-D casts suspended in kaolin clay fills of lacustrine and riparian areas proximal to fluvial channels. Evidence presented interprets these specimens as organic in origin, consisting of coprolites and other bromalites (cololites), at the Readlyn deposit of the Whitemud Formation (Maastrichtian) in southern Saskatchewan and the Salmon Creek deposit of the Wilkes Formation (Miocene) near Toledo, Washington State. Comparable taphonomic processes at each deposit are suggested by preservation of identical, metre-long, enigmatic casts of the digestive system (cololites) of an unknown animal associated with the innumerable coprolites. Micro-fabrics of specimen interiors suggest that microbial mats entombed faecal and other organic entities in kaolin-rich lacustrine muds. This research proposes that microbial-induced ferrihydrite precipitation rapidly transformed into thin encrustations of goethite, encasing faecal droppings and other organic remains. Ferrihydrite-goethite-hematite biomineral sequencing cemented kaolin and quartz silt grains at the interface with the organic remains, precluding significant decay and thereby preserving external surface morphologies as encrustations. The mm-thick layers of the cemented sediment enveloped the organic droppings as rigid goethite moulds, preventing the collapse of the encasement morphologies as the organic residues were replaced by biominerals. Concentric growth layers of microbial mat-induced ferrihydrite-goethite cement progressed inward, resulting in 3-D casts. Only external morphologies were preserved, but often with finely detailed surface textures. The interiors of the casts preserve evidence of interconnected fabrics of pseudomorphed bacterial cell walls consisting of radially arranged jackets of acicular (Readlyn deposit) or platy (Salmon Creek deposit) goethite crystallites. Concretionary siderite replacement fabrics in some specimens resulted in the obliteration of the earlier microbial induced biomineral fabrics. Previous interpretations that the Wilkes Formation specimens resulted from inorganic processes only, thereby pseudo-coprolites, have been reappraised as faecal droppings comparable to coprolites of the Whitemud Formation.
... But scientists who've looked into this are not sure that they are coprolites at all. In a paper published way back in 1993, Patrick Spencer proposed a completely different explanation for the occurrence of the would-be coprolites (Spencer 1993; see also Mustoe 2001). Imagine a rotting hollow log. ...
Book
The practice of paleontology has an aesthetic as well as an epistemic dimension. Paleontology has distinctively aesthetic aims, such as cultivating sense of place and developing a better aesthetic appreciation of fossils. Scientific cognitivists in environmental aesthetics argue that scientific knowledge deepens and enhances our appreciation of nature. Drawing on that tradition, this Element argues that knowledge of something’s history makes a difference to how we engage with it aesthetically. This means that investigation of the deep past can contribute to aesthetic aims. Aesthetic engagement with fossils and landscapes is also crucial to explaining paleontology’s epistemic successes.
... According to these authors, the coprolites taxonomy is limited by the similarity of the faeces produced by both related and non-related taxa (Chin & Gill 1996;Chin & Kirkland 1998;Ambwani & Dutta 2005;Chin 2007b;Bianchi et al. 2011;Mil an 2012;Bajdek et al. 2014); the variability of the morphologies and contents of the faeces produced by the same individual or species depending on seasonal, ontogenetic or health variables (Chin 2007b;Bisceglia et al. 2008;Mil an 2012); and the preservational bias of the coprolites after biostratinomic and diagenetic conditions (Hunt et al. 1994;Chin & Kirkland 1998;Tapanila et al. 2008). Further, coprolite-shaped inorganic structures (pseudo-coprolites) are often confused with fossil scats when only the morphology is considered (Spencer 1993;Mustoe 2001;Francischini et al. 2016). Following this discussion, it is difficult to apply the binomial coprotaxonomy on the Santa Maria Formation coprolites in order to recognize two or more ichnotaxa. ...
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Terrestrial tetrapod coprolites are abundant in the Middle to Late Triassic of southern Brazil, but only few specimens have been described in just a couple of papers. Here we revisit the already-known specimens and describe new materials, including their size, shape, external modifications, matrix composition and rare inclusions. Regarding size and shape, the measurements of 152 specimens show that the Triassic coprolites of Brazil follow a normal distribution, in which length and width are positively correlated variables, so that they are not useful for taxonomic purposes. Notwithstanding, two ichnotaxa, Santamariacopros elongatus and Rhynchocopros soutoi, were previously described from the Middle/Upper Triassic Santa Maria Formation, based mainly on morphological (length/width ratio) and preservational features, but we discuss here the validity of such taxa. Once the Santa Maria Formation encompasses at least three tetrapod Assemblage Zones (AZ), Dinodontosaurus AZ, Santacruzodon AZ and Hyperodapedon AZ (from the oldest to the youngest, respectively), it is difficult to attribute these coprolites to any specific animal producers. In addition, the rarity of inclusions and the carbonated composition of the coprolites, related to early diagenetic processes, complicate this attribution too. Nevertheless, some rare inclusions as a hair-like structure and a parasite egg were found in this study. Although the coprotaxonomy fails to represent the Santa Maria Formation coprolites and the recognition of their producers is a problematic task, these fossil dungs are important elements in the knowledge of the Middle to Late Triassic environments of southern Brazil.
... Enigmatic excrement or intestine-shaped sideritic and limonitic structures are known from various formations, including the Upper Permian of China, the Upper Cretaceous of Saskatchewan and Madagascar, the Upper Miocene of the state of Washington, USA, as well as the Paleocene of North Dakota (Broughton et al., 1978;Seilacher et al., 2001;Broughton, 2016). Their origins have been variously interpreted as coprolites or pseudofossils (see Mustoe, 2001). Seilacher et al. (2001) suggested that they are cololites (intestinal casts) and that the absence of bone remains and phosphate could be explained by the action of roll-fronts of oxidized groundwater that destroyed phosphatic bones, but favored siderite precipitation. ...
Article
Residues of twenty-five coprolite fragments collected from the Upper Permian of Vyazniki (European Russia) were studied in detail. The phosphatic composition, general shape and size, and bone inclusions of these specimens indicate that medium to large-sized carnivores, such as therocephalian therapsids or early archosauriforms, were the most likely coprolite producers. The contents of the examined fossils (i.e. scale, bone and tooth fragments, mineral grains, and microbial structures) do not differ significantly among the samples, implying fairly comparable feeding habits of their producers. Fragments of large tooth crowns in two of the analyzed samples imply that either (1) the coprolite producer swallowed the cranial elements of its prey or (2) the coprolite producer broke and swallowed its own tooth while feeding (such tooth damage is known in archosaurs that have tooth replacement, e.g. crocodiles and dinosaurs). Indeed, the most complete tooth fragment in these fossils is serrated, most likely belonging to an early archosauriform known from skeletal records from the Late Permian of Vyazniki. Another coprolite fragment contains the etched tooth of a lungfish, while putative actinopterygian fish remains (scales and small fragments of bones) are abundant in some samples. Mineral particles (mostly quartz grains, feldspars and mica) may have been swallowed accidentally. The preserved microbial colonies (mineralized fossil fungi and bacteria or their pseudomorphs), manifested in the coprolites as Fe-rich mineral structures, seem to have developed on the expelled feces rather than on the items before they were swallowed.
... Polarized interpretations on the morphogenesis of these coprolites, alternatively pseudo-coprolites, have focused on the massive deposit in the Wilkes Formation (upper Miocene) at the lower Horseshoe Bend site along Salmon Creek in southern Washington State, USA (Spencer 1993;Mustoe 2001). For more than 50 years, this deposit has been widely studied and is the most controversial of the three major deposits hosting these similar sideritic specimens. ...
... Many specimens are observed to have a continuous unbroken extrusive flow, but others, usually larger specimens (>5 cm) have shapes that suggest welded overlapping tubular forms. The shapes of specimens recovered from the Wilkes Formation site have been extensively documented by numerous authors, including Spencer & Tuttle (1980), Spencer (1993) and Mustoe (2001), and those from the Whitemud Formation site by Broughton et al. (1978) and . Fewer detailed descriptions are available for specimens from the Golden Valley Formation site in North Dakota (Jepsen 1963;Seilacher et al. 2001). ...
... For example, concretionary crystalline masses without resemblance to any faecal-like forms are widely distributed at the Wilkes Formation site, in contrast to only infrequent observations (<1%) at the Whitemud Formation site. Microscopic to mm scale bowtie-shaped siderite crystals and spherulitic aggregates occur in both the Wilkes Formation (Mustoe 2001) and Whitemud Formation beds (Fritz et al. 1971;Binda et al. 1991). Such incipient sideritic crystallization is commonplace in kaolinitic palaeosols. ...
... Taking this problem into consideration, some authors have reviewed the authenticity of several fossilized faeces. Spencer (1993) and Mustoe (2001) analyzed the sideritic, spindleeshaped, coiled and concretionary structures of the Upper Cretaceous Whitemud and Wilkes formations of North America, diagnosed as coprolites by Roberts (1958). Due to their ferruginous composition, absence of internal inclusions and scarcity of vertebrate remains at this locality, the authors proposed that these excrementeshaped structures are in fact pseudoecoprolites produced by the methanogenesiserelated deformation of the organicerich silt and clay, forcing the sediment injects into hollow logs. ...
Article
Pseudo-coprolites are inorganic structures often confused with fossil faeces. The absence of some diagnostic features, such as inclusions, coprofabrics, grain adhesion, and defined shape, suffices to disregard these structures as coprolites. Herein we revise the soecalled “coprolites” from the Serra da Galga Member of the Marília Formation (Maastrichtian of Bauru Group, Paraná Basin), at “Ponto 1 do Price” locality near the town of Peirópolis (Uberaba municipality, Minas Gerais State, Brazil) and conclude that they are, in fact, pseudo-coprolites related to calcretes. These data also agree with the geological setting of “Ponto 1 do Price”, composed mainly of coarse sandstones and conglomerates, in which these pseudo-coprolites were found. In addition, some of these specimens exhibit superficial traces, here described as a new boring ichnospecies, Asthenopodichnium fallax isp. nov., produced by invertebrates in Late Cretaceous freshewater settings of Brazil.
... Taking this problem into consideration, some authors have reviewed the authenticity of several fossilized faeces. Spencer (1993) and Mustoe (2001) analyzed the sideritic, spindleeshaped, coiled and concretionary structures of the Upper Cretaceous Whitemud and Wilkes formations of North America, diagnosed as coprolites by Roberts (1958). Due to their ferruginous composition, absence of internal inclusions and scarcity of vertebrate remains at this locality, the authors proposed that these excrementeshaped structures are in fact pseudoecoprolites produced by the methanogenesiserelated deformation of the organicerich silt and clay, forcing the sediment injects into hollow logs. ...
Article
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The Paleontological Site “Ponto 1 de Price” (19°43’24.6’’S / 47°44’45.4’’W) is an important and historically known outcrop located near the Peirópolis town (Uberaba County, Minas Gerais State, Brazil). The succession in this locality has been referred to the Maastrichtian Serra da Galga Member of the Marília Formation (Bauru Group, Paraná Basin). The outcrop includes a caliche (carbonatecemented claystone) layer at the base, followed by a cyclic succession of cross-bedded fine- to coarse-grained sandstones and conglomerates, recording deposition within a fluvial system. The sandstone beds contain isolated (e.g., eggshells, teeth, turtles shells, bones remains and coprolites) and semi-articulated elements (e.g., the peirosaurid Uberabasuchus and the titanosaur Trigonosaurus) of several groups, such as fish, anurans, turtles, crocodiliforms and dinosaurs, and invertebrate trace fossils (aff. Arenicolites and Skolithos). Contrarily, the conglomerates only contain fragmentary remains. We report here the discovery of non-oriented bierosion structures, consisting of concave, long, rod-like shape borings with a length mean of 8.6 mm, width of 2 mm and a depth of 2.8 mm (n=9). These ichnofossils are preserved in elypsoid to irregular carbonate-rich structures, which are interpreted as vertebrate coprolites. The presence of cracks crosscutting the trace fossils in some coprolites suggests that they dried and desiccated after the production of the borings. Therefore, the presence in both sandstones and conglomerate facies indicates that the vertebrate-feces should have already been lithified before their transportation and deposition. The trace fossils are randomly located, concentrated on one hemisphere of the coprolite, commonly forming clusters where one trace fossil could overlaps another, and be absent on the opposite sides. They resemble the shape of Petroxestes pera Wilson & Palmer and Cubiculum ornatus Roberts et al., made by marine boring bivalves and continental osteophagous insects, respectively. Despite P. pera is produced on carbonate rocks (or hardgrounds) and C. ornatus on bones, the aforementioned ichnofossils were made in a fecal matrix, possibly by an insect in the pupation period (e.g. dung flies or beetles). In some specimens, sub-transversal lines (bioglyphs) are preserved and can be interpreted as excavation and accommodation traces before the pupation. Thus, the ichnological record from the Marília Formation is extended, encompassing not only invertebrate burrows and vertebrate coprolites, but also the pupation marks here reported, representing the first record of Pupichnia in Brazil and the first occurrence of this behavior on a coprolite surface.
... Similar ichnofossils occur in the Permian of China, and in the Cretaceous of Canada and Madagascar, and there has been a long debate as to their origin (coprolites, pseudofossils or casts of internal organs), particularly with regard to those from the late Miocene of Washington (e.g., Amstutz, 1958;Brown, 1962;Broughton et al., 1977;Broughton, 1981;Schmitz and Benda, 1991;Spencer, 1993;Mustoe, 2000;Seilacher et al., 2001). Seilacher et al. (2001) convincingly argued that these specimens are both ichnofossils and cololites (sensu Agassiz, 1833;Hunt and Lucas, 2012a) that represent fossilized sections of the gastro-intestinal tract of vertebrates. ...
... Discussion: These ichnofossils have been identified from the Permian of China, the Cretaceous of Canada and Madagascar, and the Paleocene and Miocene of the United States and have variously been interpreted as coprolites, pseudofossils or casts of internal organs (Amstutz, 1958;Broughton et al., 1977;Broughton, 1981;Schmitz and Benda, 1991;Spencer, 1993;Mustoe, 2000;Seilacher et al., 2001). Seilacher et al. (2001) argued that they are both ichnofossils and cololites and we concur with this conclusion. ...
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The National Museum of Natural History (Smithsonian Institution, Washington, D. C.) contains one of the largest collections of vertebrate coprolites (and other bromalites) in the world. Specimens come from the middle-upper Paleozoic (
... Subsequently, McAllister (1988) convincingly argued that the specimens described by Williams (1972) and Stewart (1978) were, in fact, evacuated materials and therefore coprolites. Seilacher et al. (2001) discussed the origin of trace fossils from the Permian of China, the Cretaceous of Canada and Madagascar, and the Miocene of the United States that had often been variously been interpreted as coprolites, pseudofossils, or casts of internal organs (Amstutz, 1958;Broughton et al., 1977;Broughton, 1981;Schmitz and Benda, 1991;Spencer, 1993;Mustoe, 2000). They convincingly argued that they are both ichnofossils and cololites. ...
Article
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Buckland introduced the term coprolite for fossil excrement. During the last 50 years, an increasing number of workers have discussed the terminology of coprolites and associated trace fossils (e.g., gastro-intestinal tract infillings and regurgitated material), particularly with regard to spiral forms. More clarity and consistency is needed in the use of terminology for vertebrate trace fossils. Ichnofossils use a different terminology than modern animal traces, and several principles are important in assessing the nomenclature of vertebrate trace fossils: (1) ichnofossils should have a terminology distinct from that applied to Recent traces; (2) priority of terminology is important; (3) stability of nomenclature should be maintained; (4) universality of usage should be considered in the choice of terms; (5) when possible, there should be consistency in etymology and usage; and (6) the terminology should have practical utility. We propose a comprehensive and internally consistent hierarchical terminology for bromalites and related ichnofossils. Some of the most important terms are " coprolite " (all trace fossils that represent food items that have entered the oral cavity or gastrointestinal tract and have been expelled or retained within them), " consumolite " (fossilized food material preserved in, or partially in, the body cavity), " demalite " (skeletal material preserved within the body cavity of an animal that do not pertain to it), " cumulite " (fossil accumulation of organic or inorganic material concentrated by an organism), " gignolite " (trace fossils and body fossils related to reproduction) and " gastrolith " (a hard object of no caloric value that is, or was, retained in the digestive tract of an animal).