Mark Wilson

College of Wooster · Department of Geology

A Late Pennsylvanian (Gzhelian) Tubiphytes reef from Guizhou Province, southern China, is a new type of triple hybrid carbonate buildup mainly constructed by in situ Tubiphytes, microbes, corals, and abundant marine synsedimentary cement. The Tubiphytes reef indicates the formation of a notable abiotic-microbial-skeletal hybrid carbonate in a high-...

The Ediacaran taxon Conotubus hemiannulatus has been discovered in the Terreneuvian blue clays of Estonia. Alongside Conotubus, Gaojiashania-like tubes are also found in these clays. These tubes are fully compressed and pyritized. The well-developed peristomes of Conotubus might have provided stability if the living worm was partially buried in the...

2024. New parasitic organisms in a productid brachiopod Eomarginifera lobata from the lower Carboniferous of the Moscow Basin, Russia. Acta Palaeontologica Polonica 69 (3): 403-410. Bioclaustrations are among the best ways that parasitic associations are preserved. A new bioclaustration, Haplorygma productidophilia csp. nov., is here described from...

The Upper Silurian exposures on Saaremaa Island, mostly represented by small coastal cliffs, are the best in Estonia. Among these exposures are two coastal cliffs that are in many ways unique. The Pridoli crinoid fauna at Kaugatuma and the Ohesaare cliffs contains several endemic genera such as Methabocrinus, Saaremaacrinus, and Velocrinus, which o...

Two new spirorbin species, Neomicrorbis israelicus sp. nov. and Spirorbis? hagadolensis sp. nov., are here described from the Callovian of Israel, together with two new variations of Neomicrorbis israelicus from the late Bathonian of northern France and Callovian of Madagascar. These are the geologically earliest true Spirorbinae. Our new data, and...

Four species of Conchicolites and two species of Cornulites occur in the Hirnantian of Estonia. Two new cornulitids Conchicolites corbalengus sp. nov. and Cornulites levigatus sp. nov. have been described from the Siuge Member. This Hirnantian cornulitid tubeworm association is dominated by species of Conchicolites. Most likely, the studied tubewor...

A new cornulitid genus and species, Porkuniconchus fragilis new genus and species, is here described from the Ärina Formation (Hirnantian, Porkuni Regional Stage) of northern Estonia. This new taxon differs from most cornulitids by having a fusiform ornamentation pattern that is somewhat similar to that of Kolihaia . All studied specimens are attac...

The abundant shells and hardgrounds in the Cincinnatian Group (Upper Ordovician, Katian) of the upper midwestern United States were commonly encrusted and bored by a variety of organisms. Numerous studies of these sclerobiont communities have provided valuable data for models of ecological succession, sym�biosis, space and food resource competiti...

Non-destructive 3D imaging technology is used to determine if it can aid taxonomic identification of Palaeozoic palaeostome bryozoans. In previous studies it has not proved very successful with calcified specimens because the density contrast between the walls and zooecial infill is too weak to resolve the interior details. However, X-ray Micro Co...

A steinkern of an endoceratid nautiloid siphuncle contains a Trypanites sozialis boring with a lingulate brachiopod Rowellella sp. shell inside. The steinkern of this endoceratid formed during early lithification of the sediment on the seafloor. The lithified steinkern of this siphuncle was either initially partially exposed to the seawater or was...

The evolution of brachiopod symbiosis is closely tied to the evolution of brachiopod faunas and their partner groups during the early Palaeozoic. Brachiopod groups with a larger number of taxa had more symbiotic associations, and there was no specific group that was more prone to symbiosis during this time interval. The first symbiotic associations...

There was a sudden increase in the diversity of bioclaustrations in the Sandbian (Late Ordovician) that continued somewhat more slowly in the Katian. The Sandbian was also the time when bioclaustrations became common, at least in Baltica. The major increase in the diversity of bioclaustrations in the Late Ordovician was an outcome of the GOBE, and...

Nine crinoids are described from the Wooster Shale Member of the Cuyahoga Formation from Wayne and Ashland counties, Ohio, USA. Identifiable elements of the fauna include five camerate crinoids, one flexible crinoid, and three other eucladid crinoids. Five new species are described, including Cactocrinus woosterensis n. sp., Cusacrinus brushi n. sp...

The fossil record yields a peculiar phenomenon in different kinds of molluscan shells: bioclaustrations formed around (epi)symbionts during growth of the hosts' shell margin. Four morphologies, two of them formerly considered bioerosion traces, are here united in the para-taxonomy of bioclaustration structures under the revised cecidogenus Rodocana...

Trepostome bryozoans, with their thick calcitic skeletons, formed the largest number of symbiotic associations with endobionts in the Phanerozoic. Such associations were also formed by cystoporates, fenestrates, cy-clostomes and cheilostomes. Bryozoans formed most of their symbiotic associations with endobiotic cnidarians, and markedly fewer with e...

Valves of the strophomenid brachiopod Sowerbyella tenera are often encrusted by trepos-tome bryozoan colonies in the lower Katian of Estonia. In some cases, the encrustation of Sowerbyella likely took place syn vivo. A single Sowerbyella tenera contains three Palaeosabella prisca borings that were bored post mortem into the interface between the en...

Stromatolites, among the earliest fossils in Earth's history, are widely distributed on the margins of the North China Precambrian carbonate platform. The formation processes of stromatolites reveal the biomineralization and evolution of early life in the Precambrian. The well-preserved stromatolitic dolostones recorded in the Ganjingzi Formation a...

Seven species of cornulitids, one unidentified tubicolous shell, and the problematic bryozoan Lagenosypho Spandel, 1898 are here described from the Katian of Baltica. Three new species— Cornulites lindae new species, Cornulites meidlai new species, and Conchicolites kroegeri new species—are described. The unidentified tubicolous organism has puncta...

Endobiotic cornulitids formed symbiotic associations with tabulate corals and stromatoporoids in the Katian (Late Ordovician) of Estonia. The cornulitids benefited from a stable substrate and additional protection against predators offered by the skeleton of their hosts. Symbiotic lingulates and Chaetosalpinx-like bioclaustration structures are her...

A new bioclaustration of a symbiont is here described from the mantle cavity of the strophomenatan brachiopod Clitambonites schmidti. It is the second bioclaustration in brachiopods known from the Kukruse Regional Stage (Sandbian) of Estonia. It shares affinities with the bioclaustrations Burrinjuckia and Haplorygma. The outgrowth in the ventral va...

Bryozoans were common benthic invertebrates in the Silurian seas. The large biodiversity among Silurian benthic organisms prompted diversified interactions, and as a result bryozoans hosted many other organisms as symbionts. Here we analyse the cystoporate bryozoan Fistulipora przhidolensis and unidentified trepostomes intergrown with auloporid tab...

A crinoid attachment structure has been found with its radices extending into the skeleton of a stromatoporoid (Clathrod-ictyon variolare) from the Adavere Regional Stage of Estonia (early Silurian, Telychian). This boring made by a crinoid is provisionally assigned to the ichnogenus Podichnus. The crinoid likely used chemical means for boring into...

Nine rhynchonellid brachiopods from the Matmor Formation (Jurassic, Callovian) of Hamakhtesh Hagadol (Kurnub Anticline), southern Israel are described herein. Two new species are erected: Baeorhynchia begini n. sp. and Kallirhynchia radulovici n. sp. The Matmor Formation consists of Middle-Late Callovian alternating carbonates that reach a thicknes...

A phoronid-like hederelloid that formed a symbiotic association with the rugosan coral Entelophyllum has been found in the Pridoli Series of Estonia. The skeletons of the hederelloid and rugosan are partially intergrown. The hederelloid apertures are located at the margin of the rugosan calice. The hederelloid lophophore was likely placed between t...

We report morphology and microstructure of the stromatolites of the Ganjingzi Formation in southern Liaoning. Sedimentologic and morphologic analyses indicate that the lower stromatolite mounds formed in a transgressive succession, while the stromatolite columns in the more complex upper biostrome changed vertically from dispersed growth to dense c...

Parasitic associations involving colonial animals are farily evenly distributed through the post-Cambrian Phanerozoic and have a long evolutionary history. Parasitism may have played an important role in the evolution of colonial animals. In the Paleozoic, the majority of marine symbioses involved colonial animals, and it is likely that colonial an...

Ooimmuration is here defined as a taphonomic process by which fossils are preserved within ooids. It is a form of lithoimmuration, although depending on the role of microbes in the formation of the ooid cortex, ooimmuration can also be considered a type of bioimmuration. Fossils enclosed within ooids are protected from bioerosion as well as the abr...

Molecular evidence has long indicated that aquatic animals called bryozoans should be found among the fossils of the Cambrian period, around 541 million years ago. Yet they have been conspicuously absent, until now. The discovery of elusive fossils provides insight into animal evolution.

Anoigmaichnus bioclaustrations (A. odinsholmensis, A. bretti, and A. isp.), unidentified large bioclaustrations, small conical bioclaustrations, cornulitids and conulariids occur in the Sandbian trepostome bryozoans of Estonia. The most abundant symbionts in the middle Sandbian bryozoans were Anoigmaichnus odinsholmensis bioclaustrations, making up...

Multiple calcareous worm-like boring casts occur on the inner surface of the calcitic external layer of the bivalve Leptodesma sp. from the Kaugatuma Formation (lower Přídolí, Upper Silurian) of Saaremaa Island, Estonia. Most of the boring casts are oriented with their apertures towards the posterior margin of Leptodesma sp. The worm-like casts wer...

A new ichnospecies, Caupokeras badalloi, is here erected from the Emsian (Lower Devonian) Aguión Formation of Asturias, NW Spain. It is a bioclaustration structure produced by the host-specific symbiotic intergrowth of two host bryozoan species, Leioclema elegans and Loxophragma cf. leptum, and a soft-bodied modular symbiont, possibly a hydroid. Th...

Rare Oichnus simplex drill holes occur in mature obolid shells from the Cambrian/Ordovician boundary beds of northern Estonia (Iru and Ülgase) and the uppermost Cambrian of NW Russia (Lava River). The drill holes are significantly more common in the central rather than the marginal regions of the obolid valves. Drilling predators attacked Ungula in...

Relatively few Hirnantian (Late Ordovician) crinoids are known, and none has been previously described from the palaeocontinent of Baltica. This has impaired our ability to understand the patterns of extinction and biogeographic dispersal surrounding the Late Ordovician mass extinction, which triggered a major turnover in crinoid faunas. Here, we d...

The Cambrian explosion (CE) and the great Ordovician biodiversification event (GOBE) are the two most important radiations in Paleozoic oceans. We quantify the role of bioturbation and bioerosion in ecospace utilization and ecosystem engineering using information from 1367 stratigraphic units. An increase in all diversity metrics is demonstrated fo...

A new bioclaustration structure is described from the Emsian (Lower Devonian) Aguión Formation of Asturias, NW Spain. It is the result of intergrowth of two bryozoan species, Leioclema elegans and Loxophragma cf. leptum, hosting an unknown soft-bodied modular symbiont. These structures point to the development of host-specific symbiotic association...

In the Silurian, the most common hosts of endobiotic rugose corals were stromatoporoids followed by tabulate corals. Here we describe the relationship between rugose corals and a bryozoan. Solitary rugosans and the cystoporate bryozoan Fistulipora przhidolensis Kopajevich, 1990 formed a symbiotic association in the late Silurian (Pridoli) of Saarem...

Bioconstructions (five biostromes, one patch reef, and one large reef) of the colonial coral Fomichevella are well exposed, if infrequent, in the Upper Pennsylvanian-lower Permian of the Houchang area (southern Guizhou, China). Though they are primarily built by the same species, different growth morphologies and internal constructions are evident,...

Cornulites sp. and Fistulipora przhidolensis formed a symbiotic association in the Pridoli (latest Silurian) of Saaremaa Island, Estonia. This Cornulites sp.–F. przhidolensis association is the youngest example of cornulitid–bryozoan symbiosis. Symbiosis is indicated by intergrowth of both organisms. The cornulitids are completely embedded within t...

In this study, we report the chemical composition of early carbonate cement precipitates in carbonate hardgrounds to understand the geochemical signature of near‐surface carbonate mineral precipitation. As carbonate hardgrounds lithify at or near the sediment‐water interface, they acquire cements that may be minimally evolved from paleoseawater. Us...

Three new Llandovery (early Silurian) crinoids from Estonia provide an improved understanding of the paleogeographic aspects of the crinoid diversification following the end-Ordovician extinctions. The new taxa are Euspirocrinus hintsae new species (Rhuddanian eucladid), Oepikicrinus perensae new genus new species (Aeronian camerate), and Rozhnovic...

A light grey nautiloid conch has a dark brown colony attached to its internal surface. This colonial fossil resembles hederellids and bryozoans, but is in fact a crustoid graptolite (Hormograptus? sp.). The colony has been lithoimmured inside this nautiloid conch by early cementation. Crustoid graptolites were a part of the encrusting communities i...

The earliest Petroxestes borings were excavated in large trepostome bryozoans in the Sandbian (earliest Late Ordovician) of Estonia. The Estonian specimens are morphologically similar to the type material from the later Katian of North America. Petroxestes pera is rare in the Sandbian of Estonia and occurs only in biogenic hard substrates. Petroxes...

Compared to modern counterparts, bioerosion is rare in Paleozoic reefs, especially macro-bioerosion. The unique and enigmatic Silurian reefs from Gotland (Sweden), composed of bryozoans and microbial laminates, show evidence of a large amount of bioerosion. The samples contain Trypanites trace fossils, as well as a large number of undescribed macro...

A new rugose coral-cystoporate bryozoan association is described here from the Devonian of NW Spain. It is the first evidence of intergrowths between Devonian rugose corals and bryozoans. In this case bryozoans provided a suitable substrate for the settlement of corals, which were subsequently encrusted by the bryozoans. The hypothesis of intergrow...

The Kalana Lagerstätte of early Aeronian (Llandovery, Silurian) age in central Estonia preserves a diverse shallow marine biota dominated by non-calcified algae. This soft-tissue flora and decalcified and calcified crinoids are preserved in situ, in a lens of microlaminated, dolomitized micrite interbedded in a sequence of dolomitized packstones an...

The trepostome bryozoans Diplotrypa abnormis, D. bicornis, D. petropolitana, Esthoniopora communis, Esthoniopora subsphaerica, Mesotrypa excentrica, M. expressa, M. raritabulata, and Monotrypa jewensis have symbiotic associations with the conulariid Climacoconus bottnicus in the Upper Ordovician of Estonia. All bryoimmured conulariids are very smal...

Thirteen bryozoan species are described from the Brewer Dock (Hickory Corners) Member of the Reynales Formation (lower Silurian, Aeronian) at the locality Hickory Corners in western New York, USA. Three species are new: trepostomes Homotrypa niagarensis n. sp. and Leioclema adsuetum n. sp. and the rhabdomesine cryptostome Moyerella parva n. sp. Onl...

A combination of encrusting calcitic bryozoans and early seafloor dissolution of arago-nitic shells recorded in the Cincinnatian Series of the upper Midwest of North America allowed the preservation of abundant moulds of mollusc fossils bioimmured beneath the attachment surfaces of the bryozoans. We here call this preservational process 'bryoimmura...

A bryozoan-dominated fauna that inhabited small caves underneath a carbonate hardground is here described from the Corryville Formation (Upper Ordovician, Katian) exposed near Washington, Mason County, Kentucky, USA. The dominant bryozoan, Stigmatella personata (a trepostome), is found both growing downwards from the cave ceilings and upwards on th...

The studied cases of bioclaustration appear in the green and red marls unit, between La Vela Cape and the Arnao beach, which is 24 m thick. This unit is renowned for its rich marine fauna including abundant bryozoans, echinoderms, corals and brachiopods. Here we show interactions between bryozoans and corals and other unindentified fauna.

Pyritized filamentous cyanobacteria have been discovered by scanning electron microscopy of Ordovician brachiopods from nineteenth century collections in the Natural History Museum, London. The cyanobacteria form mats on strophomenid brachiopods from the Cincinnatian Group (Upper Ordovician, Katian) near or in Cincinnati, Ohio. There is no addition...

Well-preserved encrusting chaetetids are widespread and easily observed in limestones of the Benxi Formation (Moscovian, Upper Carboniferous) in the Benxi area, eastern Liaoning Province, North China. Chaetetids and colonial corals were the framework-building organisms, with chaetetids as the most common fossils in several small-scale reefs of the...

Ancient and modern marine carbonate hardgrounds offer unusual opportunities to study the evolution of communities from the Early Cambrian into the Holocene. Throughout this time the general physical conditions of a hardground community have been similar. The substrate is hard so sessile organisms must either attach to its surface, nestle in cavitie...

The Global Ordovician Biodiversification Event (GOBE) was undoubtedly one of the most significant evolutionary events in the history of the marine biosphere. A continuous increase in ichnodiversity occurs through the Ordovician in both shallow- and deep-marine environments. The earlier view that early Paleozoic deep-marine ichnofaunas are of low al...

Rhuddanian crinoid faunas are poorly known globally, making this new fauna from the Hilliste Formation of western Estonian especially significant. The Hilliste fauna is the oldest Silurian fauna known from the Baltica paleocontinent, thus this is the first example of the crinoid recovery fauna after the Late Ordovician mass extinction. Hiiumaacrinu...

Ichnodisparity has been recently introduced as a concept to assess the variability of morphologic plans in biogenic structures, revealing major innovations in body plan, locomotory system and/or behavioral program. Whereas ichnodiversity is measured in terms of the number of ichnotaxa (i.e. ichnogenera or ichnospecies), ichnodisparity is evaluated...

Zigzagopora wigleyensis n. gen. n. sp. is an Upper Ordovician (Sandbian, early Caradoc) cyclostome bryozoan from the Arbuckle Mountains of Oklahoma, USA. It has runner-type colonies characterized by a mostly uniserial, geniculate arrangement of monomorphic zooids that bud alternately left and right, producing a zig-zag pattern of growth. This new g...

Significance The majority of body plans were established during the Cambrian Explosion (CE), whereas the significant taxonomic increases during the Great Ordovician Biodiversification Event (GOBE) were manifest at lower taxonomic levels. Data on the diversity and disparity of bioturbation and bioerosion indicate that soft and hard substrate communi...

Conichnus conicus and Amphorichnus papillatus occur in clay-rich carbonate rocks in the Ordovician of Estonia. Conichnus conicus also occurs in clay-rich carbonates of the early Silurian of Estonia. Lateral adjustment traces are more common in C. conicus than previously recorded. The lack of adjustment traces in Amphorichnus, together with its morp...

Thirteen symbiotic associations occur in the Silurian of Baltica. Symbiosis was especially prominent among colonial animals, most commonly with stromatoporoids. These sponges hosted the most diverse fauna of endobiotic symbionts (including rugosans, Syringopora, ‘polychaetes’, cornulitids and lingulids). This pattern can be explained by the abundan...

Bryozoans are among the most abundant fossils in the Ordovician, especially in the Cincinnatian Series of northern Kentucky, which makes understanding their interactions with other fauna critical for interpretation of Ordovician ecosystems. Bioclaustrations are formed when a soft-bodied organism settles on a living skeletal organism and the skeleto...

Rare pits attributed to Tremichnus have been found in crinoids from the Silurian of Estonia. The Rhuddanian Tremichnus is the earliest symbiont in crinoid columnals of Baltica. These pits presu-mably were domiciles of unknown organisms. Tremichnus had a negative effect on the host crinoid as demonstrated by swollen columnals. Tremichnus in the Silu...