The Winneshiek Lagerstätte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerstätte has yielded an atypical marine fauna including phyllocarid crustaceans, eurypterids, conodonts, linguloid brachiopods, and jawless fish. Associated with these taxa are vermiform fossils: elongate, morphologically variable, and often three-dimensionally preserved bromalites of uncertain organisms. The preservational state of these bromalites is significantly different from that of other components of the Winneshiek biota. Here we present a compositional and microstructural analysis of the vermiform fossils in order to elucidate their taphonomy and biological affinities. The majority of studied specimens are preserved three-dimensionally and composed of calcium phosphate, while a minority are preserved as carbonaceous compressions. Winneshiek bromalites exhibit important similarities to examples documented from both older and younger sediments. They provide independent evidence of predation in the Winneshiek assemblage during the Great Ordovician Biodiversification Event.

A new ichnofossil-Lagerstätte from the Miocene Vilanova Basin (NE Spain) is described. It is characterized by bioerosion structures that are exceptionally preserved as positive casts, many associated with internal and external molds of mollusk shells (gastropods and bivalves). Five main ichnotaxa were identified: Caulostrepsis contorta, C. taeniola, Entobia cateniformis, E. geometrica, and Gastrochaenolites dijugus, produced by annelids, sponges and bivalves, respectively. Combination of ichnological, taphonomical, and systematic data allows the concentration to be interpreted as the result of several storm events that mixed shells from a diverse array of marine environments during the biostratinomical phase. Bioerosive episodes took place before and after storms, and diagenetic processes produced external and internal shell molds and fine casts of the borings.

Horizontal and inclined U-shaped trace fossils are commonly associated with the Cruziana and Glossifungites ichnofacies, but have rarely been described as a component of the Teredolites ichnofacies (xylic substrates). This study provides several examples of morphologies of Glossifungites saxicava from the Campanian Sunnyside Coal (Blackhawk Formation) that exhibit both xenoglyphs and bioglyphs. Glossifungites along this surface are locally present as compound ?Thalassinoides suevicus-Glossifungites, which may represent a combination of commensalism, an exploited structural weakness, refugium from predators, and/or a secondary behavior of the presumed crustacean tracemakers. The trace-fossil assemblage also contains Teredolites clavatus and Teredolites longissimus and Radichnus isp. locally. Stratigraphically, this trace assemblage is important because it marks a marine flooding surface/transgressive surface of erosion between the Sunnyside and Grassy members of the Blackhawk Formation.

Here we report a locality containing exceptionally preserved (soft-bodied) fossils of mid-Late Ordovician age from the geologically complex Martinsburg Formation in central Pennsylvania. The fossils, which resemble specimens from Burgess Shale-type deposits, include enigmatic specimens (problematica) and phyllocarid arthropods (with preserved appendages) which are associated with graptolites. The locality is notable for preservation of a low diversity community of soft-bodied planktic animals, likely captured and rapidly buried by a turbidity current. The problematica lack sufficient anatomical detail for confident systematic placement; however, they can be superficially compared to a number of possible metazoans including: nominally/non- shelled mollusks (including veligers), cnidarians, lophophorates, or possibly aberrant tube-dwelling priapulids or polychaetes. Overall, the problematica may belong to one (or several) extinct clades or some unknown clade of animal life. The complex geologic history of the region has reduced the resolution of the problematica's original exceptional preservation, yet the fossils retain many key features. Hence, this locality has implications for our understanding of exceptional preservation, its alteration over geological history, and the planktic communities of “The Great Ordovician Biodiversification Event” (GOBE) in the planktic realm.